Indiana University of Pennsylvania
Knowledge Repository @ IUP
Theses and Dissertations
5-2014
Laryngeal Diadochokinetic Task Consistency in
the Geriatric Population
Jaclyn K. Hynson
Indiana University of Pennsylvania
Follow this and additional works at: http://knowledge.library.iup.edu/etd
Recommended Citation
Hynson, Jaclyn K., "Laryngeal Diadochokinetic Task Consistency in the Geriatric Population" (2014). Theses and Dissertations. Paper
1204.
This Thesis is brought to you for free and open access by Knowledge Repository @ IUP. It has been accepted for inclusion in Theses and Dissertations
by an authorized administrator of Knowledge Repository @ IUP. For more information, please contact [email protected].
LARYNGEAL
DIADOCHOKINETIC
TASK
CONSISTENCY
IN
THE
GERIATRIC
POPULATION
A
Thesis
Submitted
to
the
School
of
Graduate
Studies
and
Research
in
Partial
Fulfillment
of
the
Requirements
for
the
Degree
of
Master
of
Science
Jaclyn
K.
Hynson
Indiana
University
of
Pennsylvania
May
2014
©
2014
by
Jaclyn
K.
Hynson
All
Rights
Reserved
ii
Indiana
University
of
Pennsylvania
School
of
Graduate
Studies
and
Research
Department
of
Special
Education
and
Clinical
Services
We
hereby
approve
the
thesis
of
Jaclyn
K.
Hynson
Candidate
for
the
degree
of
Masters
of
Science
3‐24‐14
Signature
on
file
___________________________
______________________________________________
3‐24‐14
___________________________
Lori
E.
Lombard,
Ph.D.,
CCC‐SLP
Professor
of
Speech‐Language
Pathology,
Advisor
Signature
on
file
_________________________________________________
3‐24‐14
__________________________
David
W.
Stein,
Ph.D.,
CCC‐SLP
Professor
of
Speech‐Language
Pathology
Signature
on
file
_________________________________________________
Cynthia
McCormick
Richburg,
Ph.D.,
CCC‐A
Professor
of
Audiology
ACCEPTED
Signature
on
file
________________________________________________
Timothy
P.
Mack,
Ph.D.
Dean
School
of
Graduate
Studies
and
Research
iii
________________________________
Title:
Laryngeal
Diadochokinetic
Task
Consistency
in
the
Geriatric
Population
Author:
Jaclyn
K.
Hynson
Thesis
Chair:
Dr.
Lori
E.
Lombard
Thesis
Committee
Members:
Dr.
David
W.
Stein
Dr.
Cynthia
McCormick
Richburg
Consistent
production
of
repetitive
phonatory
tasks
requires
intact
fine
motor
control
of
laryngeal
musculature.
Repetition
of
glottal
syllables
/hʌ/
and
/ʌ/,
the
two
laryngeal
diadochokinetic
(LDDK)
tasks,
isolates
laryngeal
functioning
by
eliminating
oral
involvement
during
phonation.
Existing
literature
has
identified
LDDK
task
performance
as
an
assessment
of
laryngeal
function
with
the
potential
to
identify
the
presence
of
neuromuscular
disorders.
However,
current
research
on
LDDK
does
not
provide
sufficient
normative
data
for
its
use
as
a
meaningful
clinical
measure.
The
purpose
of
this
study
was
to
collect
and
compare
data
for
/ʌ/
and
/hʌ/
to
determine
production
consistency
in
47
normal
participants
between
the
ages
of
60
and
90
years.
Gender
comparisons
were
also
identified.
Mean,
standard
deviation,
and
range
were
established
for
male
and
female
participants
60
to
90
years
of
age.
Results
revealed
no
statistically
significant
task
or
gender
differences.
iv
ACKNOWLEDGEMENTS
Without
the
contributions
of
following
individuals,
this
thesis
would
not
have
been
possible,
much
less
the
enjoyable
and
enriching
process
that
it
was:
Dr.
Lori
Lombard
Caleb
McKelvy
Alan
and
Victoria
Hynson
The
McKelvy
and
Murphy
Families
Hanna
Gratzmiller
Megan
Liptak
Caitlin
Ferry
Kathryn
Young
Lauren
Azeles
Maggie
Bodenlos
Dr.
Lisa
Price
Dr.
Cynthia
Richburg
Dr.
David
Stein
IUP
SLP
Class
of
2014
With
sincerest
gratitude,
I
wish
to
thank
you
all
for
your
assistance,
guidance,
and
encouragement
during
this
process.
v
TABLE
OF
CONTENTS
Chapter
Page
I
REVIEW
OF
THE
LITERATURE.......................................................................................... 1
Introduction..........................................................................................................................................1
Diadochokinesis..................................................................................................................................2
Laryngeal
Diadochokinesis........................................................................................................4
Anatomy
and
Physiology
of
the
Larynx....................................................................................5
Anatomy
and
Physiology ............................................................................................................5
Innervation .................................................................................................................................... 10
Neurologic
Disease ..................................................................................................................... 11
Aging
of
the
Larynx .................................................................................................................... 13
Gender
Considerations ............................................................................................................. 15
Common
Tests
of
Laryngeal
Function.................................................................................... 16
Laryngeal
Diadochokinesis......................................................................................................... 17
Existing
LDDK
Research........................................................................................................... 18
Tasks
and
Procedures ............................................................................................................... 19
Variables
Affecting
LDDK
Values.......................................................................................... 21
Sample
Size
and
Generalizability ......................................................................................... 24
Implications
of
Current
Literature .......................................................................................... 25
II
PURPOSE ...................................................................................................................................28
III
RATIONALE..............................................................................................................................30
IV
METHOD....................................................................................................................................31
Design................................................................................................................................................... 31
Participants........................................................................................................................................ 31
Recruitment................................................................................................................................... 31
Inclusion
and
Exclusion
Criteria........................................................................................... 32
Final
Sample
Size......................................................................................................................... 32
Data
Collection
Procedures......................................................................................................... 33
Ethical
Use
of
Data .......................................................................................................................... 35
Statistical
Analysis .......................................................................................................................... 36
V
RESULTS....................................................................................................................................38
VI
DISCUSSION .............................................................................................................................42
VII
LIMITATIONS ..........................................................................................................................44
VIII
IMPLICATIONS........................................................................................................................48
REFERENCES .........................................................................................................................49
APPENDIX:
CONSENT
FORMS........................................................................................54
vi
LIST
OF
TABLES
Table
Page
1
Multivariate
Analysis
of
Task ...........................................................................................39
2
Descriptive
Statistics
for
Consistency
of
LDDK
Production................................40
3
Univariate
Analysis
of
Gender..........................................................................................41
vii
CHAPTER
I
REVIEW
OF
THE
LITERATURE
Introduction
Several
measures
are
available
to
evaluate
laryngeal
function.
Such
assessments
are
used
to
reveal
both
structural
and
neurologic
changes
affecting
the
vocal
folds
and
their
vibratory
patterns.
Surgery,
aging,
lesions,
and
neurologic
disease
can
all
cause
disruptions
in
laryngeal
functions,
such
as
phonation
and
swallowing.
Laryngeal
diadochokinesis
(LDDK),
the
topic
of
this
study,
examines
fine
motor
control
of
laryngeal
muscles
by
measuring
the
rate
and
consistency
of
phonatory
tasks
that
require
rapid,
voluntary
adduction
and
abduction
of
the
vocal
folds.
Variations
in
the
ability
to
adduct
and
abduct
the
vocal
folds
quickly
and
consistently,
as
measured
by
LDDK
task
performance,
demonstrate
changes
in
the
fine
motor
control
necessary
for
phonation
and
swallowing.
Abnormal
LDDK
values
may
be
early
predictors
of
systemic
neurologic
disease
or
other
conditions
affecting
fine
motor
control
in
the
larynx.
However,
to
use
LDDK
as
a
predictive
and/or
diagnostic
measure
of
laryngeal
function,
data
must
be
collected
from
the
normal
population.
Sufficient
data
do
not
currently
exist
to
determine
whether
the
LDDK
values
obtained
from
a
patient
are
abnormal.
The
larger
study,
of
which
this
study
is
a
part,
aims
to
collect
sufficient
LDDK
data
to
calculate
normative
values
for
male
and
female
participants
between
the
ages
of
20
and
90
years.
This
smaller
study
has
three
purposes:
(a)
to
determine
if
there
is
a
difference
between
LDDK
consistency
of
production
for
/hʌ/
and
/ʌ/;
(b)
to
establish
normative
values
for
non‐disordered
participants
between
the
ages
of
60
and
90
years;
and
(c)
to
compare
male
and
female
values
in
that
population.
1
Diadochokinesis
Diadochokinesis
(DDK)
is
a
widely
used
method
of
detecting
motor
function
abnormalities.
Leeper
and
Jones
(1990)
define
DDK
as
“the
function
of
arresting
one
motor
impulse
and
substituting
one
that
is
diametrically
opposed….
commonly
examined
through
the
use
of
rapid
alternating
motions”
(p.
880).
Oral
DDK
is
frequently
used
as
a
perceptual
method
of
oral‐motor
assessment,
but
it
does
not
have
clearly
defined
parameters
with
regard
to
task
design
or
administration
procedures
(Williams
&
Stackhouse,
2000).
It
is
most
often
used
by
speech‐language
pathologists
in
the
clinical
setting
to
evaluate
fine
motor
control
of
oral
articulators
(e.g.,
lingua
and
labial
muscles)
as
a
way
to
screen
for
neuromotor
disorders
(Wang,
Kent,
Duffy,
Thomas,
&
Weismer,
2004).
The
diametrically
opposed,
rapidly
alternating
motions
described
by
Leeper
and
Jones
(1990)
are
created
by
tasks
of
repeating
syllables
(e.g.,
/pʌ/,
/tʌ/,
and
/kʌ/)
individually
and
in
various
combinations
of
sequences.
Oral
DDK
has
been
shown
to
be
“a
sensitive
indicator
of
the
presence
and
severity
of
neurological
impairment
and
evolution
of
changes
over
time
in
both
developmental
and
acquired
disorders”
(Gadesmann
&
Miller,
2008,
p.
42).
However,
the
selected
syllables
are
variable,
as
is
the
use
of
sequences
or
lone
syllables,
dependent
upon
examiner
choice
(Kent,
Kent,
&
Rosenbek,
1987).
Nonsense
syllables
(e.g.,
/pʌtʌkʌ/)
are
preferable
as
stimuli
over
linguistically
meaningful
stimuli,
as
DDK
is
not
designed
to
measure
linguistic
skill,
but
instead
neuromotor
ability.
Thus,
“one
of
the
underlying
assumptions
in
DDK
tasks
is
that
the
observed
level
of
performance
is
predominantly
the
result
of
neuromotor
abilities
and
not
linguistic
competencies”
(Williams
&
Stackhouse,
2000,
p.
267).
It
stands
to
reason
that
this
same
assumption
is
applicable
to
DDK
performed
by
the
laryngeal
muscles
only
(i.e.,
glottal
syllable
repetition
for
LDDK
tasks).
2
Oral
DDK
research
also
evidences
the
sensitivity
of
consistency,
accuracy,
and
rate
of
production
as
measures
of
neuromotor
control.
Williams
and
Stackhouse
(2000)
even
found
that
consistency,
the
measure
being
examined
in
this
study,
was
a
more
sensitive
measure
than
accuracy
and
rate
in
children
between
the
ages
of
3‐
and
4‐years.
In
that
study,
children
with
phonological
delays
were
inaccurate,
but
consistent
in
their
errors,
while
children
with
motor
programming
deficits
had
inconsistent
productions.
Although
Williams
and
Stackhouse
(2000)
examined
DDK
productions
of
children
and
not
adults,
Wang
et
al.
(2004)
found
that
adult
TBI
participants
had
longer
and
less
consistent
DDK
syllable
durations
than
the
control
group,
as
well
as
slower
rates.
Furthermore,
Ackermann,
Hetrich,
and
Hehr
(1995)
found
that
patients
with
Parkinson’s
disease,
Huntington’s
chorea,
Fredreich’s
ataxia,
and
cerebellar
syndromes
demonstrated
abnormal
DDK
performance
regarding
at
least
one
of
four
measures:
rate,
median
syllable
duration,
variance
of
median
syllable
duration,
and
articulatory
precision.
Ackermann
et
al.
(1995)
also
found
that
patients
with
Parkinson’s
disease
and
Friedrich’s
ataxia
had
a
“highly
specific
profile
of
diadochokinesis
performance”
(p.
15).
This
evidence
supports
the
contention
that
DDK
rate
and
consistency
are
sensitive
measures
for
assessing
and
even
differentiating
among
motor
disorders.
Although
there
are
limited
normative
data
available
for
DDK,
secondary
to
the
perceptual
nature
and
variable
task
designs,
there
is
sufficient
evidence
that
DDK
is
a
valid
and
sensitive
test
of
neuromotor
abilities.
Despite
the
limited
normative
data,
oral
DDK
is
a
widely
used,
practical
method
of
assessing
motor
coordination
and
control
as
a
way
to
screen
for
motor
and
neurologic
disorders.
The
evidence
of
its
sensitivity
gives
support
to
the
idea
that
DDK
may
have
clinical
utility
for
any
body
mechanism
that
can
perform
diametrically
opposed
tasks
in
rapid
3
succession
(e.g.,
the
larynx).
However,
research
has
shown
that
without
the
combination
of
oral
DDK
perceptual
measurement
with
an
objective
measure
of
performance
(e.g.,
simultaneous
sound
spectrogram)
and
collection
of
data
with
standardized
tasks
and
procedures,
reliability
is
subject
to
human
error
(Gadesmann
and
Miller,
2008).
Therefore,
when
applying
DDK
assessment
to
the
larynx
(i.e.,
LDDK)
with
the
intention
of
using
the
assessment
as
a
diagnostic
or
outcome
measure,
procedures
and
tasks
must
be
defined
and
standardized,
as
well
as
objectively
measured.
Normative
data
must
then
be
obtained
if
LDDK
is
to
be
established
as
a
reliable
protocol
for
the
detection
of
dysfunction.
Laryngeal
Diadochokinesis
Verdolini
&
Palmer
(1997)
describe
LDDK
as
a
clinical
test
used
to
assess
laryngeal
function
through
the
“repeated
production
of
glottal
plosives
for
several
seconds
as
consistently
and
quickly
as
possible”
(p.
219).
The
repetitive
production
of
glottal
syllables
requires
the
arytenoid
cartilages
to
open
and
close
in
a
controlled,
rapid
and
repetitive
manner.
Because
the
syllables
are
produced
at
the
level
of
the
glottis
and
do
not
involve
oral
articulation,
laryngeal
function
can
be
isolated
in
assessment.
Like
DDK,
LDDK
has
been
shown
to
be
a
sensitive
and
valid
test
of
neuromotor
function,
but
sufficient
normative
data
do
not
exist
(Boutsen,
Cannito,
Taylor
&
Bender,
2002;
Fung
et
al.,
2001;
Leeper
&
Jones,
1991;
Modolo,
Berretin‐Felix,
Genaro,
&
Brasolotto,
2011;
Ptacek,
Sander,
Maloney
&
Jackson,
1966;
Sander,
Maloney,
&
Jackson,
1966;
Shanks,
1966;
Renout,
Leeper,
Bandur
&
Hudson,
1995;
Verdolini
&
Palmer,
1997).
The
current
study
aims
to
provide
such
normative
LDDK
data,
but
first,
it
is
important
to
understand
the
anatomical
and
physiologic
integrity
of
the
larynx,
crucial
to
the
ability
to
perform
the
diametrically
opposed
glottal
tasks
in
rapid
succession.
4
Anatomy
and
Physiology
of
the
Larynx
Understanding
the
structures,
movements,
and
innervation
of
the
larynx
is
critical
to
comprehending
laryngeal
functions
of
phonation
and
swallowing,
as
well
as
the
fine
motor
control
required
to
perform
LDDK
tasks.
The
laryngeal
mechanism’s
ability
to
perform
functions
that
are
both
vegetative
(e.g.,
coughing,
swallowing,
thoracic
fixation)
and
communicative
(e.g.,
phonation)
is
reliant
upon
the
integrity
of
the
cartilaginous
framework,
the
articulation
of
laryngeal
muscles
with
laryngeal
cartilages,
and
the
innervation
of
those
muscles.
Changes
or
damage
to
this
anatomy
can
affect
functioning
of
the
entire
mechanism,
functioning
that
can
be
measured
through
LDDK
assessment.
Five
aspects
of
laryngeal
functioning
are
important
to
understand:
1)
the
anatomy
and
physiology;
2)
the
innervation;
3)
the
effects
of
neurologic
disease;
4)
the
effects
of
aging;
and
5)
gender
considerations.
Anatomy
and
Physiology
The
larynx,
located
at
the
level
of
the
third
through
sixth
cervical
vertebrae
in
the
anterior
neck,
is
a
mostly
cartilaginous
organ
that
connects
the
respiratory
system
to
the
vocal
tract.
It
is
suspended
from
the
hyoid
bone
by
infrahyoid
muscles,
enabling
the
larynx
to
be
elevated
during
a
swallow.
The
larynx’s
vegetative
and
communicative
functions
are
enabled
by
the
complex
arrangement
of
connective
tissue,
muscles
and
mucous
membranes
(Stemple,
Glaze,
&
Klaben,
2010).
Congenital
or
acquired
deviations
from
normal,
possibly
resulting
from
surgery,
lesions,
aging
or
disease,
often
cause
functional
deviations.
There
are
nine
laryngeal
cartilages
including
three
single
cartilages
(epiglottic,
thyroid
and
cricoid)
and
three
sets
of
paired
cartilages
(arytenoid,
corniculate,
and
5
cuneiform).
These
cartilages
protect
and
support
the
soft
tissues
that
preserve
the
airway.
There
are
three
levels
of
airway
protection
that
comprise
the
laryngeal
valve.
The
aryepiglottic
folds
form
the
upper
boundary
of
the
larynx,
connecting
the
epiglottis
and
arytenoid
cartilages.
During
a
swallow,
the
epiglottis
tips
posteriorly
and
inferiorly
to
cover
the
entrance
of
the
larynx
and
protect
the
airway,
serving
as
the
first
sphincter
of
the
laryngeal
valve.
The
ventricular
folds
are
superior
to
the
thyroarytenoids
and
the
ventricle
of
Morgagni,
providing
medial
closure
if
necessary
and
forming
the
second
sphincter
of
the
laryngeal
valve.
The
ventricular
folds,
or
false
vocal
folds,
may
be
activated
during
effortful
voice
production
(e.g.,
muscle
tension
dysphonia)
or
to
increase
intrathoracic
pressure
for
extreme
vegetative
functions
(e.g.,
coughing
and
sneezing).
The
thyroarytenoids,
or
true
vocal
folds,
are
the
third
and
final
sphincter
of
the
laryngeal
valve,
providing
medial
closure
for
vegetative
and
non‐speech
tasks,
protecting
the
airway
(Stemple
et
al.,
2010).
The
true
vocal
folds
are
also
the
source
of
phonation.
As
air
is
exhaled
from
the
lungs
in
a
controlled
manner
with
the
activation
of
thoracic
and
abdominal
muscles,
the
thyroarytenoids
adduct
and
abduct
to
command
the
airflow.
Vocal
fold
adduction
causes
the
airway
to
form
a
narrow
constriction.
Air
passing
through
the
constriction
triggers
the
Bernoulli
effect,
which
perpetuates
vocal
fold
vibration,
producing
sound
(Stemple
et
al.,
2010).
Phonation
can
be
sustained
as
long
as
there
is
adequate
airflow
and
adductory
muscles
maintain
the
constriction.
When
the
vocal
folds
abduct,
eliminating
the
glottal
constriction,
phonation
ceases.
The
intrinsic
laryngeal
muscles
control
the
length,
tension
and
position
of
the
vocal
folds
by
changing
cartilage
positions
and
glottal
configuration.
There
are
five
intrinsic
laryngeal
muscles,
four
adductors
and
one
abductor.
The
adductor
muscles
are
the
6
cricothyroid,
thyroarytenoids,
lateral
cricoarytenoids,
and
interarytenoid
muscles.
The
abductor
muscle
is
the
posterior
cricoarytenoid.
Activation
of
a
single
or
combination
of
intrinsic
laryngeal
muscles
can
cause
abrupt
changes
in
vibration
patterns
(Zhang,
2009).
These
vibratory
patterns
determine
voice
quality
(Qui
&
Schutte,
2007).
Fine
motor
control
of
the
intrinsic
laryngeal
muscles
is
vital
for
any
phonatory
task,
particularly
in
the
performance
of
the
repetitive
and
precise
syllable
productions
used
in
LDDK.
The
cricothyroid
contracts
to
bring
the
cricoid
and
thyroid
cartilages
closer
together,
causing
the
vocal
folds
to
stretch
and
lengthen
anteriorly.
This
movement
enables
the
speaker
to
control
the
frequency
of
vocal
fold
vibration,
or
the
pitch
of
their
voice.
The
thyroarytenoid
muscles
contribute
to
the
overall
shape
and
the
edge
of
the
vocal
folds,
as
well
as
the
closure
patterns
of
the
glottis.
There
are
two
components
of
each
thyroarytenoid,
the
thyromuscularis
and
the
thyrovocalis
(Stemple
et
al.,
2010).
Contraction
of
the
thyroarytenoids
shortens
the
folds
and
causes
the
mass
of
the
folds
to
shift
to
the
medial
edge.
Thus,
the
thyroarytenoids
are
involved
in
fundamental
frequency,
intensity,
medial
compression,
and
glottal
closure
(Stemple
et
al.,
2010;
Zhang,
2009).
The
lateral
cricoarytenoid
contracts
to
medially
rotate
the
arytenoid
cartilages,
causing
the
vocal
folds
to
adduct.
The
interarytenoids
contract
to
pull
the
arytenoid
cartilages
closer
together,
resulting
in
adduction
of
the
vocal
folds,
particularly
at
the
posterior
portion
of
the
glottis.
The
posterior
cricoarytenoid
muscle
contracts
to
laterally
rotate
the
arytenoids,
causing
the
vocal
folds
to
abduct
for
both
respiration
and
unvoiced
sound
production
(Stemple
et
al.,
2010).
The
fine
motor
control
of
these
intrinsic
laryngeal
muscles
is
paramount
to
successful
LDDK
task
performance.
7
Speech
is
a
prime
example
of
the
fine
motor
coordination
abilities
of
the
human
body.
Kent,
Kent,
Weismer,
and
Duffy
(2000)
described
speech
as,
“a
remarkable
motor
accomplishment
in
which
sound
segments
are
produced
at
rates
of
up
to
30
per
second
in
a
precisely
coordinated
action
that
requires
more
muscle
fibers
than
any
other
human
mechanical
performance”
(p.
273).
The
speed
and
coordination
with
which
fine
motor
adjustments
must
be
made
during
speech,
and
also
swallowing,
require
that
central
nervous
system
(CNS)
and
peripheral
nervous
system
(PNS)
function
be
unimpaired
(Kent
et
al.,
2000).
Disruptions
in
CNS
and
PNS
functions
can
result
in
motor
speech
disorders
(e.g.,
the
dysarthrias)
and
consequently
affect
the
speed
and
consistency
with
which
oral
DDK
and
LDDK
syllables
can
be
produced.
Similar
to
speech,
LDDK
performance
is
the
quintessential
embodiment
of
fine
motor
control
in
the
human
body.
Repeated,
rapid
activation
of
the
adductory
and
abductory
intrinsic
laryngeal
muscles
(e.g.,
LDDK
glottal
syllable
tasks)
requires
significantly
greater
fine
motor
control
than
more
passive
laryngeal
activities,
such
as
sustained
phonation.
Whereas
in
sustained
phonation
the
adductory
muscles
are
initially
activated
during
exhalation
in
order
to
trigger
the
Bernoulli
effect
and
establish
the
passive,
“flow‐induced
self‐oscillating
system”
(Stemple,
Glaze,
&
Klaben,
2000,
p.
55),
LDDK
tasks
push
the
fine
motor
control
limits
of
the
adductory
and
abductory
muscles.
Like
oral
DDK,
which
is
“seen
as
a
particularly
sensitive
index
of
motor
speech
impairments
because
it
requires
maximum
performance”
(Ziegler,
2002,
p.
556),
LDDK
requires
maximum
performance
of
agonistic
and
antagonistic
muscle
groups
(i.e.,
adductory
and
abductory
intrinsic
laryngeal
muscles).
In
order
to
perform
the
adductory
and
abductory
glottal
syllable
tasks,
the
CNS
must
communicate
with
the
PNS
to
alternate
activation
of
the
8
adductory
and
abductory
intrinsic
laryngeal
muscles
as
quickly
and
consistently
as
possible.
This
communication
will
be
discussed
in
depth
in
the
innervation
section.
As
a
logical
extension
of
oral
DDK
research,
individuals
with
motor
disorders
will
likely
demonstrate
decreased
rate,
accuracy
and
consistency
of
LDDK
performance
(Verdolini
&
Palmer,
1997;
Williams
&
Stackhouse,
2000;
Ziegler,
2002).
Thus,
normative
LDDK
rate
and
consistency
values
are
important
to
establish,
as
abnormal
values
may
reflect
the
fine
motor
coordination
deficits
often
symptomatic
of
neurologic
disease,
lesions,
or
peripheral
nerve
injury
(Love
&
Webb,
1992).
Even
in
the
presence
of
intact
motor
control,
structural
abnormalities
can
still
interfere
with
the
ability
of
the
laryngeal
muscles
to
contract
and
articulate
with
cartilages
to
achieve
phonation,
as
well
as
to
rapidly
and
consistently
perform
the
alternating
movements
required
for
LDDK
tasks.
Benign
lesions
(e.g.,
nodules,
vocal
cysts,
or
polyps)
present
in
the
lamina
propria
of
the
thyroarytenoids,
increases
the
mass
of
the
affected
fold(s),
slowing
the
potential
vibratory
rate.
If
only
one
fold
is
affected,
that
fold
will
have
increased
mass
and
the
symmetry
of
vibration
may
be
skewed.
Asymmetrical
vibration
can
affect
rate
and
may
also
affect
consistency.
Increased
medial
compression
can
compensate
for
most
structural
abnormalities
in
attaining
glottal
closure,
but
some
abnormalities
(e.g.,
larger
benign
lesions
and
laryngeal
cancer)
are
significant
enough
in
size
to
prevent
glottic
closure.
Laryngeal
cancer
can
obstruct
glottal
closure
ability
by
causing
mass
and
flexibility
changes
in
the
affected
vocal
fold(s).
However,
cancer
can
also
be
present
in
or
invade
any
part
of
the
larynx,
possibly
affecting
the
ligaments,
cartilages,
and
any
of
the
muscles.
Depending
on
the
areas
affected
by
cancer,
there
may
be
no
phonation,
or
certain
movements
might
be
hindered
(Stemple
et
al.,
2010).
If
there
is
no
phonation,
LDDK
9
assessment
will
not
provide
any
further
clinical
insights
due
to
clients’
inability
to
perform
the
required
tasks.
Innervation
Nerve
damage
can
significantly
affect
laryngeal
muscle
performance,
and
therefore
LDDK
performance,
by
hindering
the
communication
of
efferent
and
afferent
information
between
the
brain
and
laryngeal
muscles.
The
larynx
is
innervated
by
the
vagus
nerve,
cranial
nerve
X,
with
its
superior
and
recurrent
laryngeal
nerve
branches
supplying
motor
and
sensory
innervation
to
the
laryngeal
muscles.
The
internal
branch
of
the
superior
laryngeal
nerve
(SLN)
provides
all
afferent,
or
sensory,
information
to
the
larynx.
The
external
branch
of
the
SLN
provides
the
efferent,
or
motor,
innervation
for
the
cricothyroid
muscle.
In
recent
years,
it
has
also
been
empirically
suggested
that
the
SLN
may
provide
a
degree
of
motor
information
to
other
laryngeal
muscles
(Sulica,
Blitzer,
&
Springer,
2006).
The
recurrent
laryngeal
nerve
(RLN)
provides
efferent
information
to
the
intrinsic
laryngeal
muscles,
with
the
exception
of
the
cricothyroid,
and
afferent
information
to
portions
of
the
trachea
and
esophagus.
Furthermore,
the
right
branch
of
the
RLN
wanders
under
the
subclavian
artery
and
the
left
branch
wanders
under
the
aortic
arch.
Understanding
the
location
and
function
of
the
SLN
and
RLN
is
paramount
when
considering
the
risk
and
effect
of
peripheral
nerve
injury
(Stemple
et
al.,
2010).
The
far‐
reaching
nature
of
these
nerves
increases
their
vulnerability
during
non‐laryngeal
surgical
procedures.
Such
injury
could
affect
swallowing,
phonation,
and
LDDK
performance.
Two
characteristics
of
the
SLN
and
RLN
enable
the
intrinsic
laryngeal
muscles
to
contract
rapidly
and
with
great
fine
motor
control,
abilities
crucial
to
the
performance
of
LDDK
tasks.
First,
the
laryngeal
nerves
have
the
second
highest
conduction
velocity
in
the
10
human
body,
slower
than
only
the
nerves
of
the
eye,
allowing
for
quick
movements
(Stemple
et
al.,
2010).
Second,
there
is
a
low
innervation
ratio
(e.g.,
an
estimated
1:10
ratio
of
axons
to
thyroarytenoid
muscle
fibers)
that
allows
for
very
fine
motor
control
of
rapid
intrinsic
laryngeal
muscle
contractions
(Santo
Neto
&
Marques,
2008).
These
quick
and
controlled
muscular
movements
are
necessary
for
phonation
and
airway
protection
during
the
swallow.
Neuropathies
and
age
can
both
influence
these
characteristics
of
the
laryngeal
nerves,
particularly
the
conduction
velocity,
and
thus
potentially
influence
LDDK
rate,
strength
and
consistency.
Neurologic
Disease
The
vagus
nerve
may
be
injured
in
isolation,
but
it
is
also
subject
to
the
effects
of
systemic
neurologic
disease.
Due
to
the
fine
motor
control
required
for
the
larynx
to
operate,
changes
in
laryngeal
function
necessary
for
the
performance
of
LDDK
tasks
may
be
an
early
indicator
of
neurologic
disease
and
should
be
investigated
in
future
research.
Canter
(1965)
explored
the
speech
characteristics
of
Parkinson’s
disease
and
found
that
some
patients
omitted
initial
phonemes
while
orally
reading
a
passage.
Inspection
of
spectrograms
supported
the
notion
that
the
participants
had
“gone
through
the
correct
articulatory
movements,”
but
were
not
“able
to
initiate
phonation
until
the
articulators
were
moving
towards
the
following
phoneme”
(p.
221).
Thus,
the
coordination
necessary
to
perform
speech
tasks,
such
as
oral
reading
or
LDDK,
is
impaired
by
neurologic
disease.
The
findings
of
the
Canter
(1965)
study
provide
a
basis
for
the
hypothesis
that
LDDK
may
be
useful
in
the
future
as
an
early
screener
for
neurologic
disease.
In
the
oral
reading
task,
patients
with
Parkinson’s
disease
(PD)
demonstrated
a
lack
of
laryngeal
coordination,
particularly
in
relation
to
oral
articulatory
performance.
This
discrepancy
11
between
laryngeal
and
oral
coordination
demonstrates
that
laryngeal
muscle
coordination
may
be
affected
earlier
than
other
muscles
in
the
body.
Correspondingly,
Bassich‐Zeren
(2004)
cited
evidence
of
vocal
dysfunction
in
patients
with
Parkinson’s
disease
with
a
significantly
higher
incidence
than
articulatory
dysfunction
(i.e.,
89%
to
45%,
respectively),
as
well
as
the
occurrence
of
vocal
dysfunction
prior
to
the
onset
of
limb
dysfunction
in
some
individuals.
If
different
muscles
are
affected
at
different
times
during
the
course
of
a
progressive
neurologic
disease,
it
is
important
to
choose
an
assessment
that
isolates
the
muscles
intended
for
measurement.
Laryngeal
diadochokinesis
isolates
laryngeal
muscle
functioning
by
eliminating
the
oral
articulatory
involvement
of
speech
tasks.
However,
Bassich‐Zeren
(2004)
contended
“voice
deficits
associated
with
PD
markedly
mirror
the
characteristics
of
vocal
aging,
suggesting
that
our
current
knowledge
base
of
laryngeal
dysfunction
in
the
PD
population
is
confounded
by
aging
effects”
(p.
4).
The
average
onset
of
Parkinson’s
disease
is
between
60
and
70
years
of
age,
and
the
incidence
of
voice
disorders
with
Parkinson’s
disease
is
89%
(Bassich‐Zeren,
2004).
Thus,
the
question
is
raised
whether
normal
age‐related
vocal
dysfunction,
discussed
in
the
next
section,
could
interfere
with
the
sensitivity
of
LDDK
screening
to
detect
Parkinson’s
disease‐related
vocal
dysfunction.
This
question
attests
to
the
need
for
normative
LDDK
data
for
the
normally
aging
population,
as
well
as
the
aging
Parkinson’s
disease
population,
in
order
to
determine
the
viability
of
LDDK
as
a
screening
tool
for
Parkinson’s
disease.
Research
has
shown
that
LDDK
is
useful
in
the
assessment
of
patients
with
other
neurologic
diseases.
For
example,
Renout
et
al.
(1995)
found
that
LDDK
has
potential
as
a
clinical
indicator
of
the
deteriorating
laryngeal
motor
control
of
patients
with
amyotrophic
lateral
sclerosis
(ALS),
for
both
bulbar
and
nonbulbar
types.
With
the
establishment
of
12
reliable
normative
data,
LDDK
should
be
clinically
useful
in
determining
the
vocal
effects
of
neurologic
disease.
It
may
eventually
be
used
to
screen
for
fine
motor
control
deviations
that
suggest
neurologic
involvement,
perhaps
even
suggest
the
type
of
neurologic
involvement
(Verdolini
&
Palmer,
1997).
However,
this
potential
cannot
be
confirmed
or
actualized
without
extensive,
reliable
normative
data.
Aging
of
the
Larynx
The
geriatric
population
is
of
particular
interest
in
the
development
of
LDDK
normative
data.
All
systems
within
the
human
body
are
subject
to
the
effects
of
aging.
The
phonatory
system
is
no
exception.
As
structural,
physiologic
and
motor
changes
occur,
voice
quality
and
phonatory
abilities
change
(Ahmad,
Yan
&
Bless,
2012).
As
the
vocal
tract
and
support
systems
(e.g.,
the
respiratory
system
and
nervous
system)
age,
geriatric
patients
experience
a
deterioration
of
vocal
endurance,
voice
quality,
frequency,
and
intensity
(Stemple
et
al.,
2010).
In
order
to
utilize
LDDK
for
the
assessment
of
disordered
individuals
in
this
population,
it
is
important
to
be
able
to
differentiate
normal
age‐related
LDDK
performance
changes
from
those
that
may
be
related
to
neurologic
disease
and
other
disorders.
Presbylaryngis,
a
normal
laryngeal
aging
process,
affects
a
high
percentage
of
the
geriatric
population
(Ahmad
et
al.,
2012).
The
onset
of
presbylaryngis
is
around
65
years
of
age,
but
it
may
be
prevented
or
stalled
by
physical
fitness
and/or
active
use
of
a
professionally
trained
voice.
Presbylaryngis
is
a
voice
disorder
that
includes
reduced
respiratory
capability,
reduced
vocal
fold
mucosa
elasticity,
and
diminishing
vocal
fold
body
tone.
Ptacek
et
al.
(1966)
found
that
male
and
female
participants
over
the
age
of
65
years
(geriatric),
male
and
female,
had
reduced
pitch
range
compared
to
young
adults.
The
13
geriatric
participants
also
had
reduced
vital
capacity,
maximum
vowel
duration,
maximum
intraoral
pressure,
and
maximum
vowel
intensity,
attributed
to
decreased
strength
of
respiratory
muscles,
loss
of
elasticity
of
the
lungs,
and
age‐related
degeneration
of
laryngeal
muscles.
Laryngeal
aging
has
also
been
shown
to
manifest
through
neuromuscular
changes
that
may
impede
the
ability
of
intrinsic
laryngeal
muscles
to
contract
rapidly
and
with
great
fine
motor
control.
Takeda,
Thomas
and
Ludlow
(2000)
used
electromyography
(EMG)
to
record
age
differences
in
thyroarytenoid
muscles’
motor
unit
action
potentials
(i.e.,
the
length
of
time
required
for
a
motor
unit
to
fire).
Takeda
et
al.
(2000)
found
that
participants
older
than
60
years
demonstrated
statistically
significant
increases
in
motor
unit
duration
compared
to
participants
younger
than
60
years.
The
participants
older
than
60
also
demonstrated
significantly
longer
durations
for
the
motor
units
innervated
by
the
left
RLN
compared
to
the
shorter
right
RLN.
In
other
words,
geriatric
participants’
vocal
folds
had
slower
and
asymmetric
neuromuscular
communication.
Slower
and
asymmetric
neural
control
of
the
vocal
folds
could
affect
the
rate
and
consistency
with
which
the
vocal
folds
can
be
voluntarily
adducted
and
abducted,
and
thus,
LDDK
rate
and
consistency
values.
Hence,
there
is
a
need
for
LDDK
rate
and
consistency
normative
values
controlled
for
age.
Presbylaryngis
also
involves
histological
changes
that
cause
the
vocal
folds
to
atrophy
and
thereby,
cause
glottal
closure
patterns
to
take
on
a
bowed
appearance.
Elastin
fibers
of
the
superior
layer
of
the
lamina
propria
become
larger
and
more
dense,
also
weaving
together
to
cause
a
thickening
and
rigidity
of
the
layer.
Changes
in
the
intermediate
layer
reduce
the
medial
bulk
of
the
vocal
folds
as
collagen
and
elastin
break
14
down
(Stemple
et
al.,
2010).
The
thinner
and
looser
intermediate
layer,
combined
with
the
thicker
and
more
rigid
superior
layer,
lead
to
bowed
glottal
closure
patterns
and
decreased
vibratory
efficiency.
These
changes
may
cause
changes
in
LDDK
performance
in
comparison
to
younger,
more
flexible
vocal
folds.
In
presbylaryngis,
the
hyaline
cartilages
also
begin
to
ossify.
This
ossification
reduces
the
dynamic
movement
potential
of
the
larynx.
When
combined
with
atrophying
muscles
with
reduced
elasticity,
this
ossification
leads
to
deviations
in
the
quickness
and
smoothness
of
laryngeal
adjustments
(Stemple
et
al.,
2010).
Such
adjustments
are
needed
for
quick
and
smooth
adduction
and
abduction
of
the
vocal
folds
to
perform
LDDK
tasks.
Ptacek
et
al.
(1966)
reported
that
geriatric
individuals
had
slower
laryngeal
diadochokinetic
rates
than
young
adults
for
repetition
of
/ʌ/,
a
task
where
“the
vocal
folds
themselves
must
act
as
‘articulators’
in
initiating
and
terminating
the
sound”
(p.
359).
The
researchers
warn
that
due
to
the
age‐related
changes
of
the
larynx,
geriatric
task
performance
should
not
be
judged
in
comparison
to
younger
adult
populations.
In
order
to
use
LDDK
measures
clinically
with
the
geriatric
population,
we
need
normative
data
that
are
controlled
for
age‐related
changes.
This
study
aims
to
provide
such
data.
Gender
Considerations
When
differentiating
the
effects
of
aging
on
vocal
production
from
other
laryngeal
abnormalities,
it
is
important
to
consider
that
male
and
female
larynges
are
not
identically
affected
by
age.
Stathopoulos,
Huber
and
Sussman
(2011)
studied
acoustic
voice
changes
in
male
and
female
participants
between
the
ages
of
4
and
93
years.
They
concluded
“changes
in
voice
production
occur
throughout
the
lifespan,
often
in
a
nonlinear
way
and
differently
for
male
and
female
individuals”
(p.
1011).
As
men
enter
the
geriatric
stage
of
15
life,
hormonal
changes
cause
their
vocal
folds
to
thin,
increasing
their
fundamental
frequency
slightly.
Conversely,
geriatric
women
experience
thickening
of
edematous
vocal
fold
changes
due
to
increased
testosterone
(Stathopoulos
et
al.,
2011).
As
age
affects
male
and
female
larynges
in
different
ways,
any
attempt
to
generate
normative
data
on
LDDK
tasks
needs
to
separate
male
and
female
participant
data
across
various
ages.
The
current
study
aims
to
collect
data
that
is
controlled
for
gender
and
age.
Common
Tests
of
Laryngeal
Function
The
three
types
of
tests
most
often
used
to
evaluate
laryngeal
function
are
endoscopy,
laryngeal
electromyography
(LEMG),
and
electroglottography
(EGG).
These
assessments
have
substantial
diagnostic
value
by
providing
measurements
of
muscle
activity
and
potential.
However,
they
are
also
expensive
and
possibly
invasive
procedures.
Endoscopy
enables
direct
visualization
of
laryngeal
anatomy.
There
are
two
types
of
endoscopy
used
to
assess
laryngeal
structure
and
function:
rigid
and
flexible
endoscopy.
Rigid
endoscopes
are
inserted
through
the
mouth
and
provide
a
high‐resolution,
magnified
view
of
the
vocal
folds
during
sustained
phonation
of
/i/.
Flexible
endoscopy
is
inserted
through
the
nose
and
allows
for
visualization
of
the
vocal
tract
and
supraglottic
area
during
connected
speech,
in
addition
to
sustained
phonation.
A
flexible
endoscope
does
not
provide
the
same
level
of
magnification
as
rigid
endoscopy,
but
rigid
endoscopy
can
only
be
used
for
the
assessment
of
sustained
phonation.
Flexible
endoscopy
is
more
invasive
than
rigid,
but
both
types
of
endoscopy
are
invasive.
Vocal
fold
abduction
and
adduction
can
be
observed
with
both
endoscopes,
however,
the
observation
is
a
perceptual
evaluation.
Thus,
endoscopy
is
invasive,
involves
expensive
instruments,
and
does
not
provide
an
objective
measurement
of
laryngeal
function.
16
Unlike
endoscopy,
LEMG
directly
measures
muscle
activity.
Laryngeal
electromyography
involves
placing
needles
through
the
neck
into
laryngeal
muscles,
testing
the
muscles’
function
and
electrical
responses
as
the
patient
is
asked
to
perform
vocal
tasks
targeting
the
intended
muscles
(Stager
&
Bielamowicz,
2010).
Laryngeal
electromyography
may
only
be
performed
by
a
neurologist
or
otolaryngologist
(Stemple
et
al.,
2010).
It
provides
accurate
and
comprehensive
data
of
muscle
function
and
potential,
but
it
is
also
invasive
and
involves
expensive
instruments.
Unlike
endoscopy
and
LEMG,
EGG
is
noninvasive.
Electroglottography
measures
the
opening
and
closing
phases
of
vocal
fold
vibration.
The
procedure
uses
an
electrical
current
passing
through
the
larynx
via
electrodes
placed
on
either
side
of
the
thyroid
alae.
The
variable
current
resistance
is
caused
by
vocal
fold
vibration,
allowing
the
electrodes
to
measure
and
record
a
real‐time
waveform.
Although
this
assessment
is
noninvasive,
it
also
involves
expensive
instruments
and
is
subject
to
error
due
to
variations
in
electrode
placement,
mucous
interference,
and
tissue
density
(Stemple,
et
al.,
2010).
The
immense
clinical
value
of
these
assessments
is
not
disputed.
However,
the
establishment
of
a
less‐
expensive
and
non‐invasive
method
of
evaluating
laryngeal
functioning,
a
method
easily
accessible
to
speech‐language
pathologists
and
physicians
alike,
could
revolutionize
the
way
laryngeal
abnormalities
are
detected.
Laryngeal
Diadochokinesis
LDDK
is
a
method
of
assessing
laryngeal
function
with
the
practical,
inexpensive,
and
non‐invasive
benefits
of
oral
DDK,
and
thus,
without
the
drawbacks
of
endoscopy,
LEMG,
and
EEG.
There
are
three
measures
of
LDDK
performance
important
to
its
diagnostic
value:
(a)
quantity
of
glottal
syllables
per
second
(rate),
(b)
strength
of
glottal
syllable
production,
and
17
(c)
the
consistency
of
glottal
syllable
production
over
time.
Abnormal
rate,
strength
and/or
consistency
values
may
indicate
and
differentiate
between
physiologic
deficits
affecting
the
larynx
(Tomblin,
Morris
&
Spriestersbach,
2000;
Verdolini
&
Palmer,
1997).
Production
of
LDDK
glottal
syllables
requires
tight
approximation
of
the
arytenoids,
a
build
up
of
subglottic
pressure,
and
the
abrupt
release
of
that
pressure
through
phonation.
It
stands
to
reason
that
if
tight
approximation
of
the
arytenoids
is
not
achievable,
the
build
up
and
release
of
subglottic
pressure
will
be
hindered.
This
will
in
turn
lead
to
decreased
rate
and
strength
of
LDDK
performance
(Tomblin
et
al.,
2000).
In
order
to
determine
if
slow
or
weak
LDDK
performance
indicates
a
peripheral
or
central
nervous
system
disorder,
consistency
values
are
key.
If
a
peripheral
disorder
(e.g.,
vocal
fold
paralysis)
causes
decreased
rate
and
strength,
the
consistency
of
LDDK
performance
should
still
be
relatively
intact
(Tomblin
et
al.,
2000).
However,
“if
there
is
a
problem
in
the
central
nervous
system
that
affects
arytenoid
control,
a
primary
problem
might
relate
to
the
temporal
aspect
of
the
production,
which
is
dysrhythmic”
(p.
261).
Thus,
abnormal
consistency
of
glottal
syllable
production
may
indicate
the
presence
of
central
nervous
system
disease
(e.g.,
Huntington’s
Disease,
ALS,
Parkinson’s
disease).
However,
existing
LDDK
research
does
not
provide
sufficient
normative
data
to
differentiate
abnormal
LDDK
consistency
values
from
normal.
Existing
LDDK
Research
LDDK
is
also
referred
to
as
vocal
fold
diadochokinesis
(VFDDK)
in
the
literature,
but
it
has
not
been
researched
to
the
extent
of
even
oral
DDK.
Regardless
of
the
acronym
selected,
multiple
researchers
have
identified
LDDK
as
an
assessment
with
the
potential
to
assess
laryngeal
function
(Boutsen
et
al.,
2002;
Fung
et
al.,
2001;
Leeper
&
Jones,
1991;
Modolo
et
18
al.,
2011;
Ptacek
et
al.,
1966;
Sander
et
al.,
1966;
Shanks,
1966;
Renout
et
al.,
1995;
Verdolini
&
Palmer,
1997)
and
even
to
differentiate
among
disorders
in
dysfunctional
larynges
(Verdolini
&
Palmer,
1997).
Some
studies
demonstrated
that
rate
can
be
calculated
objectively
with
acoustic
analysis
software,
but
that
it
can
also
be
calculated
with
no
equipment
through
a
perceptual
pencil‐dotting
calculation
of
repetitions
per
second
(Verdolini
&
Palmer,
1997).
Verdolini
and
Palmer
(1997)
also
demonstrated
that
consistency
of
production
can
be
calculated
perceptually
by
using
a
dichotomous
rating
method
(i.e.,
“good”
versus
“poor”).
No
LDDK
study
to
date
has
calculated
consistency
of
production
objectively,
but
this
study
aims
to
change
that
by
measuring
the
duration
of
glottal
syllables
(i.e.,
the
time
interval
between
glottal
syllable
onset
and
offset)
and
calculating
the
variance
of
glottal
syllable
duration.
The
perceptual
measurements
of
rate
and
consistency
used
in
the
Verdolini
and
Palmer
(1997)
study
are
convenient
in
the
absence
of
acoustic
analysis
software
or
a
microphone,
but
is
at
best
subjective
when
compared
to
objectively
obtained
normative
data.
Despite
the
agreed
potential
of
LDDK
for
assessing
laryngeal
function
in
a
non‐invasive,
inexpensive,
objective,
and
perceptual
manner,
existing
LDDK
research
is
plagued
by
inconsistent
task
selection,
variable
procedures,
and
small
sample
sizes.
Tasks
and
Procedures
Like
oral
DDK,
LDDK
studies
vary
in
their
tasks
and
administration.
Existing
literature
designates
a
vowel
combined
with
a
glottal
fricative
(e.g.,
/hʌ/
or
/hɑ/)
as
a
test
of
abductory
glottal
articulation,
and
a
vowel
alone
(e.g.,
/ʌ/
or
/ɑ/)
as
a
test
of
adductory
glottal
articulation
(Bassich‐Zeren,
2004).
Canter
(1961)
argued
that
using
the
glottal
fricative‐vowel
combination
is
a
better
task
for
LDDK
measures
than
repetition
of
a
vowel
19
alone,
as
the
lone
vowel
might
be
able
to
be
produced
through
“pulses
of
air
pressure
acting
on
a
fixed
laryngeal
valve”
(p.
60).
Conversely,
Bassich‐Zeren
(2004)
found
that
patients
with
young
onset
Parkinson’s
disease
(YOPD)
demonstrated
a
significantly
slower
rate
for
the
adductory
LDDK
task,
but
no
statistically
significant
rate
difference
between
the
healthy
control
group
and
YOPD
group
for
the
abductory
task.
This
discrepancy
evidences
the
need
for
a
comparison
of
abductory
and
adductory
performance
in
the
normal
population,
as
well
as
disordered
populations.
In
order
to
use
LDDK
clinically,
it
is
important
to
determine
if
one
of
the
tasks
is
not
as
effective
as
the
other
in
measuring
laryngeal
function,
or
if
both
tasks
are
needed
in
tandem.
The
actual
vowel
sounds
selected
as
part
of
adductory
and
abductory
stimuli
vary
among
studies
as
well.
Bassich‐Zeren
(2004)
used
stimuli
/hʌ/
and
/ʌ/,
but
/hɑ/
and
/ɑ/
were
used
in
the
Leeper,
Heeneman,
and
Reynolds
(1990)
study.
Shanks
(1966)
and
Renout
et
al.
(1995)
used
only
/hʌ/,
while
Ptacek
et
al.
(1966),
Leeper
&
Jones
(1991)
and
Vernoldi
&
Palmer
(1997)
used
only
/ʌ/.
Canter
(1965)
used
only
/hɑ/,
while
Modolo
et
al.
(2011)
and
Fung
et
al.
(2001)
used
only
/ɑ/.
Future
research
is
needed
to
determine
if
the
vowel
selected,
either
for
use
in
isolation
or
with
/h/,
affects
obtained
LDDK
values.
The
vowel
sound
chosen
may
not
affect
the
detection
of
abnormal
laryngeal
functioning,
but
until
it
is
determined
empirically
that
the
vowels
are
interchangeable,
future
LDDK
evaluations
should
only
compare
results
to
normative
values
established
using
the
same
stimuli
as
those
evaluations.
Use
of
/ʌ/
may
be
preferable
over
/ɑ/
due
to
the
phonetic
features
of
the
two
vowels,
as
/ʌ/
is
a
mid,
central,
lax
vowel
and
/ɑ/
is
a
low,
back,
tense
vowel
(Secord,
Boyce,
Donohue,
Fox
&
Shine,
2007).
The
lax,
centralized
vowel
may
require
less
oral‐muscular
involvement,
and
therefore,
lessen
oral
interference
with
the
20
isolated
measurement
of
glottal
articulation.
For
that
reason,
this
study
uses
/ʌ/
as
the
vowel
for
both
abductory
and
adductory
tasks.
Administration
of
the
tasks
varies
from
study
to
study
as
well.
Most
often,
participants
were
asked
to
repeat
the
stimuli
quickly
and
precisely
for
seven
seconds
(Bassich‐Zeren,
2004;
Ptacek
et
al.,
1966;
Verdolini
&
Palmer,
1997).
Shanks
(1966)
used
three
five‐second
trials,
calculating
rate
and
periodicity
from
the
first
three
seconds.
Leeper
&
Jones
(1991)
collected
five‐second
trials
and
used
the
middle
three
seconds
to
calculate
rate
by
repetitions
per
second.
Canter
(1965)
instructed
participants
to
produce
the
syllable
repeatedly
for
30
seconds,
and
used
five‐second
or
less
segments
to
analyze
rate
of
production
in
syllables
per
second.
Renout
et
al.
(1995)
had
participants
repeat
a
syllable
as
fast
as
possible
on
one
breath,
calculating
the
percent
of
abduction/adduction
time.
There
is
a
need
for
established,
consistent
LDDK
procedures
that
can
be
applied
across
research
studies
and
clinical
settings;
values
cannot
be
compared
to
normative
data
obtained
via
variable
procedures.
Variables
Affecting
LDDK
Values
Some
research
provides
evidence
for
what
controls
need
to
be
in
place
in
order
to
collect
optimal
LDDK
data.
Results
from
various
studies
suggest
that
normal,
conversational
intensity
and
frequency
are
necessary
to
obtain
optimal
performance
(Leeper
&
Jones,
1991;
Shanks,
1966).
Both
the
Leeper
&
Jones
(1991)
and
Shanks
(1966)
studies
were
conducted
on
female
participants
only,
and
the
affects
of
intensity
and
frequency
are
unknown
for
the
male
population.
Shanks
(1966)
and
Ptacek
et
al.
(1966)
did
not
agree
upon
the
variable
of
age.
Shanks
(1966)
found
that
age
was
not
significantly
related
to
LDDK
performance
for
the
20‐80
year
old
female
participants
of
his
study,
suggesting
that
age
would
not
need
to
be
a
21
controlled
variable.
Alternately,
Ptacek
et
al.
(1966)
found
that
geriatric
participants
had
slower
LDDK
rates,
suggesting
that
age
should
be
considered
important.
Ptacek
et
al.
(1966)
used
male
and
female
participants,
but
had
a
smaller
sample
size
than
Shanks.
Male
and
female
larynges
experience
age
differently,
so
age‐related
differences
detected
or
not
detected
in
one
gender
might
not
apply
to
the
other
gender.
Sample
size
and
participant
characteristics
could
be
reasons
for
the
conflicting
results,
illustrating
that
it
is
important
to
create
age‐/gender‐matched
groups
before
attempting
to
determine
affects
of
age
for
both
genders.
The
exclusion
criteria
for
the
two
studies
may
also
shed
light
on
their
conflicting
findings,
as
well
as
informing
future
LDDK
research.
For
women
over
the
age
of
60
years,
Shanks
(1966)
excluded
participants
with
a
hearing
loss
greater
than
22dB
in
their
better
ear
and
28dB
in
their
poorer
ear
at
500Hz,
1000Hz,
and
2000Hz.
Conversely,
participants
younger
than
60
years
were
excluded
if
they
had
greater
than
a
20dB
loss
in
either
ear.
In
this
way,
Shanks
(1966)
controlled
for
the
possible
influence
of
auditory
feedback
deficits
on
vocal
production
but
avoided
“eliminating
women
whose
hearing
acuity
was
normal
for
their
age”
(p.
24).
Shanks
(1966)
found
that
rate
of
vocal
fold
vibration
during
LDDK
tasks
was
significantly
reduced
in
the
presence
of
100dB
SPL
masking
white‐noise,
interrupting
auditory
feedback
in
the
40
normal
hearing,
young
adult
participants.
These
results
suggest
that
hearing
loss
may
contribute
to
LDDK
rate
reduction.
Ptacek
et
al.
(1966),
on
the
other
hand,
excluded
participants
with
over
a
35dB
hearing
loss.
If
hearing
loss
does
interfere
with
LDDK
performance,
Ptacek
et
al.
(1966)
may
have
found
that
age
has
a
difference
on
LDDK
rate
due
to
including
participants
with
up
to
a
35dB
loss,
7‐13dB
greater
than
the
loss
allowed
for
inclusion
in
the
Shanks
(1966)
study.
22
Because
presbycusis,
an
age‐related,
degenerative
sensorineural
hearing
loss,
is
seen
in
“most
[geriatric]
persons”
(Katz,
1978,
p.
19),
it
is
possible
that
older
participants
in
the
Ptacek
et
al.
(1966)
study
had
a
greater
age‐related
hearing
loss
than
those
in
the
Shanks
(1966)
study.
It
is
inconclusive
whether
the
conflicting
findings
were
due
to
age‐related
hearing
loss,
the
degree
of
overall
loss,
or
if
other
variables
were
responsible.
What
can
be
concluded
from
the
two
studies
is
that
the
effects
of
hearing
impairment
should
be
addressed
in
future
LDDK
research.
Due
to
the
prevalence
of
age‐related
high
frequency
loss,
but
also
the
possible
effect
of
significant
loss
on
LDDK
rate,
it
is
logical
to
include
participants
with
normal
hearing
for
their
age
and
exclude
participants
with
reported
hearing
loss
of
a
profound
degree
when
collecting
normative
data
(Shanks,
1966).
The
variable
tasks,
conditions
and
participant
characteristics
of
current
LDDK
research
present
concerns
for
the
comparability
of
existing
data.
However,
LDDK
performance
has
been
shown
to
be
consistent
with
other
measures
of
vocal
fold
dysfunction.
For
example,
Fung
et
al.
(2001)
included
LDDK
tasks
when
investigating
the
concern
that
patients
with
non‐laryngeal
head‐neck
tumors
who
received
wide‐field
radiation
treatment
had
greater
post‐treatment
vocal
dysfunction
than
patients
treated
with
targeted
radiation
for
early
glottic
tumors.
Laryngeal
diadochokinesis
performance
was
decreased
in
the
non‐laryngeal
radiation
treatment
group,
consistent
with
performance
on
other
aerodynamic
measures,
videostroboscopic
observations,
and
Voice
Handicap
Index
ratings.
Laryngeal
diadochokinesis
performance
could
not
be
compared
to
normative
data,
as
those
data
do
not
yet
exist.
However,
the
consistency
of
the
LDDK
task
performance
with
other
measures
indicating
“significant
vocal
dysfunction
when
compared
with
age
and
gender‐matched
normative
data”
(p.
1922)
suggests
that
LDDK
values
are
23
able
to
evidence
vocal
dysfunction.
However,
without
age‐
and
gender‐matched
normative
data,
LDDK
values
cannot
definitively
determine
vocal
fold
dysfunction
severity.
Laryngeal
diadochokinesis
data
can
only
supplement
data
obtained
from
assessments
that
do
have
normative
data.
The
current
study
aims
to
provide
normative
data
to
enable
LDDK
to
be
an
independently
valid
measure.
Verdolini
&
Palmer
(1997)
also
found
that
LDDK
was
able
to
distinguish
the
diagnostic
category
of
participants
with
100%
accuracy
for
seven
participants
with
nodules
and
eight
participants
with
Parkinson’s
disease,
80%
accuracy
for
five
participants
with
paralysis
profiles,
and
60%
accuracy
for
five
participants
with
granuloma
profiles.
However,
six
of
20
participants
with
normal
larynges
were
identified
as
disordered.
It
is
not
specified
if
the
six
of
20
identified
as
disordered
were
part
of
the
ten
“normal”
participants
diagnosed
with
a
functional
voice
disorder.
Nevertheless,
the
sample
size
of
both
disordered
and
normal
participants
was
too
small
to
provide
normative
data
useful
for
comparison
outside
the
confines
of
that
particular
study,
or
to
determine
that
LDDK
is
or
is
not
reliable
for
certain
diagnostic
categories.
This
limitation
brings
up
the
issue
of
sample
size
in
the
current
literature.
In
order
for
LDDK
to
be
used
clinically,
a
much
larger
sample
size
must
be
used
to
first
establish
normal
profiles
for
different
ages
and
genders,
and
then
disordered
profiles
for
the
same
populations.
Sample
Size
and
Generalizability
Sample
size
is
a
pervasive
problem
of
past
studies.
In
the
previously
mentioned
study,
Verdolini
and
Palmer
(1997)
compared
the
data
collected
from
their
participants
to
“normative”
Ptacek
et
al.
(1966)
data.
However,
Ptacek
et
al.
(1966)
only
collected
data
for
male
and
female
participants
under
40
and
over
65.
The
45
participants
of
the
Verdolini
and
24
Palmer
(1997)
study
ranged
in
age
from
17
to
78
years,
therefore,
age‐
and
gender‐matched
normative
data
were
not
actually
available
from
the
Ptacek
et
al.
(1966)
study
for
any
participants
falling
between
the
ages
of
40
and
65
years.
Verdolini
and
Palmer
(1997)
likely
made
comparisons
to
the
Ptacek
et
al.
(1966)
data
due
to
the
fact
that
it
was
and
is
the
only
study
with
a
substantial
sample
size
of
non‐disordered
male
and
female
participants
(i.e.,
58
male
participants
and
67
female
participants).
Other
existing
LDDK
studies
that
included
normal
participants
in
their
samples
used
fewer
than
20
total
normal
participants,
often
testing
only
male
or
only
female
participants
(Bassich‐Zeren,
2004;
Canter,
1965;
Leeper
&
Jones,
1991).
Sample
sizes
that
are
limited
in
these
ways
do
not
allow
for
strong
external
validity.
Only
one
study
currently
exists
with
a
large
sample
size
and
well
represented
age
groups.
Shanks
(1966)
provided
normative
data
for
120
non‐disordered
participants:
40
young
adults
(20‐40
years
old),
40
adults
(40‐60
years
old)
and
40
geriatric
adults
(60‐80
years
old).
Although
this
is
the
most
substantial
study
designed
to
provide
normative
values
for
LDDK,
all
of
the
participants
were
female.
It
is
possible
that
men
and
women
may
have
equivalent
LDDK
values,
but
men
and
women
do
not
have
identical
laryngeal
composition
or
size,
and
aging
affects
their
vocal
production
in
opposite
ways
(Stemple
et
al.,
2010).
Therefore,
there
is
need
for
a
study
to
collect
gender‐controlled
normative
data,
and
to
determine
if
LDDK
values
differ
between
genders
by
comparing
the
values
for
each
gender
in
each
age
group.
Implications
of
Current
Literature
The
current
literature’s
consistencies
and
inconsistencies
have
implications
for
how
LDDK
normative
data
should
be
collected.
Studies
have
consistently
indicated
that
normal,
25
comfortable,
conversational
intensity
and
frequency
are
necessary
production
conditions
(Leeper
&
Jones,
1991;
Shanks,
1966).
The
inconsistencies
of
the
studies
(Bassich‐Zeren,
2004;
Boutsen
et
al.,
2002;
Fung
et
al.,
2001;
Leeper
&
Jones,
1991;
Modolo
et
al.,
2011;
Ptacek
et
al.,
1966;
Sander
et
al.,
1966;
Shanks,
1966;
Renout
et
al.,
1995;
Verdolini
&
Palmer,
1997)
indicate
that
procedures
and
tasks
must
be
standardized,
or
normative
data
will
be
difficult
to
apply
to
clinical
evaluations.
Normative
data
must
also
account
for
age‐
related
changes
(e.g.,
presbylaryngis
and
presbycusis)
in
order
to
differentiate
normal
aging
from
neurologic
disease
and
other
disorders.
Age
may
not
prove
to
have
a
significant
effect
when
comparing
the
geriatric
population
by
decade,
but
those
values
may
be
significant
when
examining
the
effects
of
age
in
a
larger
study
that
encompasses
20‐90
year
olds.
Overall,
existing
literature
supports
the
use
of
LDDK
as
an
assessment
of
laryngeal
function,
with
potential
for
not
only
identifying
organic
abnormalities,
but
also
for
differentiating
among
disorders
(Boutsen
et
al.,
2002;
Fung
et
al.,
2001;
Leeper
&
Jones,
1991;
Modolo
et
al.,
2011;
Ptacek
et
al.,
1966;
Sander
et
al.,
1966;
Shanks,
1966;
Renout
et
al.,
1995;
Verdolini
&
Palmer,
1997).
Laryngeal
diadochokinesis
presents
with
significant
advantages
over
other
tests
because
it
is
practical,
non‐invasive,
and
does
not
require
expensive
equipment.
However,
LDDK
is
significantly
disadvantaged
by
not
having
empirical
support
controlling
for
age
and
gender
effects
in
a
large
sample.
Therefore,
LDDK
is
limited
in
its
clinical
value
until
such
data
are
collected
and
analyzed.
After
normal
LDDK
profiles
are
established
for
different
ages
and
genders,
disorder
profiles
can
be
researched
and
established.
With
these
types
of
data
available,
researchers
can
determine
whether
LDDK
can
serve
as
a
diagnostic
tool
to
differentiate
normal
laryngeal
function
from
disordered,
as
26
well
as
screen
for
specific
organic
disorders
using
procedures
that
are
fast,
noninvasive,
and
widely
available.
27
CHAPTER
II
PURPOSE
LDDK
assessment
is
an
inexpensive,
non‐invasive
alternative
to
flexible
endoscopy,
rigid
endoscopy,
LEMG,
and
EGG
to
assess
laryngeal
function.
Existing
literature
does
not
provide
LDDK
data
that
can
be
used
for
the
determination
of
normative
data
because
previous
studies
have
not
used
large
enough
sample
sizes
of
normal
participants
or
they
have
failed
to
use
consistent
LDDK
task
procedures.
The
purpose
of
this
study
is
to
collect
and
compare
data
for
both
LDDK
tasks,
/ʌ/
and
/hʌ/,
in
normal
participants
between
the
ages
of
60
and
90
years,
using
standardized
procedures
that
allow
for
future
replication.
Specifically,
this
study
seeks
to
identify
normative
values
for
the
consistency
of
production
for
three
trials
per
LDDK
task.
Data
will
be
classified
and
grouped
into
10‐year
age
increments,
as
well
as
by
gender.
By
creating
a
male
and
female
data
set
for
each
decade
between
ages
60
and
90
years,
normative
values
will
have
a
greater
age
and
gender
comparative
relevancy
to
future
disordered
populations.
This
study
is
part
of
a
larger
study
aimed
at
comparing
production
of
/hʌ/
and
/ʌ/
within
normal
participants
between
the
ages
of
20
and
90
years,
calculating
normative
values
by
decade
and
gender.
To
avoid
comparing
geriatric
individual
performance
to
data
collected
from
individuals
not
yet
experiencing
the
effects
of
presbylaryngis,
LDDK
data
must
be
collected
from
the
normal
geriatric
population.
To
accomplish
this,
the
following
questions
were
posed:
1. Is
there
a
difference
between
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
in
adults
between
the
ages
of
60
and
90
years?
28
2. What
are
the
normative
values
for
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task/hʌ/
in
adults
between
the
ages
of
60
and
90
years?
3. Is
there
a
difference
between
normative
values
of
laryngeal
diadochokinetic
consistency
of
production
for
male
and
female
participants?
29
CHAPTER
III
RATIONALE
The
ability
to
quickly
and
consistently
perform
alternating
adduction
and
abduction
motions
of
the
vocal
folds
necessitates
a
structurally
and
motorically
intact
laryngeal
mechanism.
Repetition
of
glottal
syllables
/hʌ/
and
/ʌ/
isolates
laryngeal
functioning
by
eliminating
oral
involvement
in
the
phonation.
By
measuring
rate
and
consistency
of
vibration
for
these
LDDK
tasks,
conclusions
of
laryngeal
integrity
can
be
drawn
in
regard
to
its
structure
and
its
ability
to
efferently
communicate
with
the
brain.
Thus,
LDDK
can
function
as
a
clinical
assessment
of
laryngeal
functioning
(Ptacek
et
al.,
1966).
In
order
to
use
LDDK
as
a
meaningful
clinical
measure,
however,
normative
data
must
be
collected
and
analyzed
for
comparative
use.
Existing
research
on
LDDK
does
not
provide
such
normative
data,
as
no
study
provides
adequate
sample
size,
evaluation
of
both
genders,
and
a
diverse
age
range.
The
data
collected
in
these
past
studies
cannot
be
combined
for
norm
establishment,
as
many
collected
data
from
disordered
individuals,
and
those
that
used
non‐disordered
individuals
had
inconsistent
tasks
and
procedures.
Furthermore,
normal
age‐related
atrophy
and
neurologic
changes
(Luschei,
Ramig,
Baker
&
Smith,
1999)
might
affect
rate
and
consistency
of
vibration
on
LDDK
tasks.
These
changes
also
affect
women
and
men
differently,
as
the
two
genders
experience
the
aging
process
in
different
ways
(Stathopoulos
et
al.,
2011).
Therefore,
it
is
important
to
collect
and
analyze
data
in
the
geriatric
population,
for
both
genders,
in
order
to
prevent
confusing
normal
age‐related
performance
changes
with
laryngeal
dysfunction.
Finally,
comparison
of
performance
between
the
two
LDDK
tasks
is
necessary
to
determine
if
the
two
tasks
measure
laryngeal
function
equally,
provide
complementary
information,
or
if
one
task
provides
better
diagnostic
information
than
the
other.
30
CHAPTER
IV
METHOD
Design
This
study
is
part
of
a
larger
ongoing
Indiana
University
of
Pennsylvania
(IUP)
Institutional
Review
Board
(IRB)
approved
study
(11‐131)
being
conducted
by
Dr.
Lori
Lombard.
This
co‐investigator
joined
the
study
December
12,
2012
to
collect
and
analyze
laryngeal
diadochokinetic
(LDDK)
values
in
normal
geriatric
male
and
female
participants
(60‐90
years
of
age).
Consistency
of
production
for
the
adductory
and
abductory
LDDK
tasks
were
compared
using
a
differential
research
design.
A
differential
research
design
is
effective
when
comparing
two
or
more
groups
established
prior
to
study
initiation.
This
design
entails
measurement
and
comparison
of
dependent
variables
between
the
two
groups
(Haynes
&
Johnson,
2009).
In
this
study,
the
participants
are
grouped
by
gender.
The
independent
variable
of
this
study
is
gender,
while
the
dependent
variables
are
LDDK
tasks.
Participants
Recruitment
Forty‐seven
adults
between
the
ages
of
60
and
90
years
were
recruited
to
participate
in
the
study.
Investigators
recruited
friends,
family,
friends
of
family,
coworkers
and
community
group
members
(e.g.,
members
of
assisted
living
facilities
and
church
care
groups).
Individuals
were
required
to
complete
the
Informed
Consent
Form
and
Voluntary
Consent
Form
prior
to
participation
in
the
study.
The
Informed
Consent
31
Form
provided
an
explanation
of
the
risks,
benefits,
and
requirements
of
participation,
of
which
participants
acknowledged
understanding
by
signing
the
Voluntary
Consent
Form.
The
IUP
IRB
reviewed
and
approved
both
forms
and
the
study
protocol
(Approval
ID:
11‐
131).
Inclusion
and
Exclusion
Criteria
The
inclusion
criterion
for
the
study
required
that
participants
have
a
normal
vocal
quality.
An
experienced
speech‐language
pathologist
specializing
in
the
evaluation
and
treatment
of
voice
disorders
screened
each
participant’s
voice
sample
for
abnormal
vocal
quality
with
the
Consensus
Auditory‐Perceptual
Evaluation
of
Voice
(“Consensus
Auditory‐
Perceptual
Evaluation
of
Voice
[CAPE‐V],”
2006).
Participants
who
received
a
disordered
rating
of
20
or
lower
were
determined
eligible
for
the
study.
There
were
eight
exclusion
criteria
for
the
study:
1)
a
disordered
rating
score
greater
than
20
on
the
CAPE‐V
(2006);
2)
vulnerability;
3)
symptoms
of
cold
or
illness
on
the
day
of
testing;
4)
history
of
respiratory,
laryngeal,
or
neurologic
disease;
5)
previous
surgeries
of
the
larynx;
6)
history
of
structural
or
dynamic
laryngeal
abnormalities;
7)
reported
hearing
loss
of
a
profound
degree;
and
8)
lack
of
comprehension
of
the
task.
Participants
meeting
one
or
more
of
the
criteria
were
excluded
from
the
study.
One
of
the
48
original
participants
was
excluded
due
to
a
history
of
stroke.
Final
Sample
Size
The
final
sample
comprised
21
male
and
26
female
participants
between
the
ages
of
60‐
and
90‐
years.
The
mean
age
of
all
47
participants
was
72.2
years
(range=60‐89
years;
SD=
8.7).
Female
participants
ranged
in
age
from
60
to
89,
with
a
mean
age
of
75.5
years
32
(SD=
7.8).
Male
participants
ranged
in
age
from
60
to
89,
with
a
mean
age
of
77.1
years
(SD=
9.8).
Data
Collection
Procedures
Documentation
of
informed
consent
and
agreement
to
participate
was
obtained
from
each
participant
prior
to
the
collection
of
data.
Data
were
collected
in
a
quiet
room
at
the
place
of
work
or
home
of
the
participant
or
investigator.
Participants
were
required
to
perform
four
tasks:
1)
produce
LDDK
tasks
/ʌ/
and
/hʌ/
for
seven
seconds,
three
times
each;
2)
sustain
the
vowels
/a/
and
/i/
for
five
seconds,
three
times
each;
3)
read
six
sentences;
and
4)
maintain
natural
conversation
for
30
seconds.
The
four
tasks
were
recorded
using
a
Roland
CD‐2
CF/CD
Recorder
and
transferred
to
a
recordable
compact
disk.
Participants
were
asked
to
sit
with
their
mouths
positioned
six
inches
from
the
Audio‐Technica
ATR20
Dynamic
Cardioid
Low
Impedance
Professional
Microphone
(Leeper
&
Jones,
1991).
Verbal
instructions
for
the
LDDK
tasks
were
modeled
after
the
Fletcher
(1972)
study
and
presented
to
the
participants
as
follows:
“I
want
you
to
say
some
sounds
for
me.
They
aren’t
words,
just
sounds.
I’ll
show
you
how
to
do
it
first,
then
you
can
say
it
with
me.
Then
you
try
it
yourself,
repeating
the
sound
as
quickly
and
consistently
as
you
can.
The
first
sound
is…
(/ʌ/
or
/hʌ/).
Try
it
with
me.
(Have
participant
practice
to
ensure
they
are
producing
the
task
correctly).
Now
I
want
you
to
do
it
once
more.
I
am
going
to
have
you
repeat
the
sound
as
quickly
and
consistently
as
you
can
for
seven
seconds,
three
times.
I’ll
tell
you
when
to
start.
Don’t
stop
until
I
tell
you.
Ready.
(Start
recording).
33
Now
I
would
like
you
to
perform
the
same
task,
but
this
time
with
the
sound…
(/ʌ/
or
/hʌ/).”
The
investigator
began
by
demonstrating
the
LDDK
tasks
for
each
participant
for
three
seconds,
producing
/ʌ/
or
/hʌ/
precisely
and
distinctly
at
a
rate
of
approximately
5‐6
repetitions
per
second.
Participants
were
given
the
opportunity
to
practice
producing
the
glottal
syllables
with
the
investigator
and
independently
to
ensure
they
understood
the
tasks.
The
participants
performed
three
trials
of
each
syllable
with
a
randomized
order
of
presentation
(Bassich‐Zeren,
2004).
Following
completion
of
the
six
trials
of
LDDK
tasks,
participants
were
required
to
complete
three
tasks
from
the
CAPE‐V
(2006)
to
assess
phonatory
function.
These
three
tasks
were
performed
after
LDDK
tasks
to
ensure
that
the
LDDK
results
were
not
affected
by
vocal
fatigue.
Participants
were
first
required
to
sustain
the
lax
vowel
/ɑ/
and
the
tense
vowel
/i/
for
five
seconds,
three
times
each.
Participants
were
then
asked
to
orally
read
six
sentences
to
identify
and
measure
laryngeal
behaviors:
1)
The
blue
spot
is
on
the
key
again;
2)
How
hard
did
he
hit
him;
3)
We
were
away
a
year
ago;
4)
We
eat
eggs
every
Easter;
5)
My
mama
makes
lemon
muffins;
and
6)
Peter
will
keep
at
the
peak.
Respectively,
these
sentences
are
designed
to
measure
an
individual’s
ability
to
produce
all
vowels
in
the
English
language,
use
easy
onset
/h/
during
connected
speech,
produce
all
voiced
speech,
use
hard
glottal
attacks,
produce
nasal
sounds,
and
to
produce
voiceless
plosive
sounds.
Finally,
participants
were
prompted
to
produce
a
30
second
conversational
language
sample
with
“Tell
me
what
you
did
yesterday”
or
“Tell
me
a
little
about
yourself”
(CAPE‐V,
2006).
34
Measurement
Procedures
Syllable
production
rate
was
identified
and
consistency
of
production
was
measured
to
evaluate
LDDK
task
performance.
The
KayPentax
Multidimensional
Voice
Program™
(MDVP)
software
was
employed
to
objectively
identify
rate
(i.e.,
number
of
syllable
productions
per
time
frame).
All
three
seven‐second
trials
of
both
/ʌ/
and
/hʌ/
repetition
tasks
were
converted
from
audio‐recordings
into
oscillograms,
using
the
MDVP
software
(Shanks,
1966).
A
five
second
selection
of
each
oscillogram,
beginning
near
the
0.5
second
mark,
was
used
for
analysis.
The
first
0.5
seconds
were
not
used
in
the
analysis
due
to
variable
vocal
stability
at
the
onset
of
each
task
(Bassich‐Zeren,
2004;
Ptacek
et
al.,
1966;
Verdolini
&
Palmer,
1997).
The
number
of
amplitude
peaks
present
in
each
five
second
segment,
one
peak
signifying
one
repetition
of
a
glottal
syllable,
was
counted
(Leeper
&
Jones,
1991;
Ptacek
et
al.,
1966;
Renout
et
al.,
1995;
Shanks,
1966).
The
best
trial
(i.e.,
greatest
number
of
peaks
in
a
five
second
period)
was
identified
for
each
task
for
each
participant.
The
best
performance
trial
was
then
analyzed
for
consistency.
Each
phonatory
cycle
of
adduction
and
abduction
was
measured
by
time.
A
cursor
was
placed
at
the
onset
of
the
phonatory
pulse
of
one
peak.
The
second
cursor
was
placed
after
the
abductory
phase
(i.e.,
breath),
but
before
the
onset
of
the
next
phonatory
pulse.
The
adductory/abductory
cycle
time
was
then
recorded
in
milliseconds.
The
variance
of
timed
cycles
was
calculated
using
SPSS
software.
Decreased
levels
of
variance
indicated
increased
levels
of
phonatory
cycle
consistency.
Ethical
Use
of
Data
Data
collected
as
part
of
this
study
were
used
solely
for
the
purpose
of
this
study
and
the
larger
study
of
which
this
study
is
a
subset.
Each
participant
was
assigned
a
35
participant
number
to
prevent
the
use
of
any
personal
identification
in
audio‐recordings
or
data
collection
paperwork.
Personal
identifying
information
present
on
the
Voluntary
Consent
Form
was
made
available
only
to
the
current
investigator
and
those
of
the
larger
study.
This
information
was
not
recorded
or
published.
All
data,
recordings,
and
paperwork
were
kept
in
a
locked
office
at
all
times
and
will
be
destroyed
upon
completion
of
the
larger
study.
Statistical
Analysis
Statistical
analyses
were
performed
using
ISPSS®
Statistics
Data
Editor
software
(SPSS
Statistics
Data
Editor,
2010)
to
obtain
answers
for
the
three
questions
posed
by
this
study:
(a)
Is
there
a
difference
between
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
in
adults
between
the
ages
of
60
and
90
years;
(b)
What
are
the
normative
values
for
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
in
adults
between
the
ages
of
60
and
90
years;
and
(c)
Is
there
a
difference
between
normative
values
of
laryngeal
diadochokinetic
consistency
of
production
for
male
and
female
participants?
For
the
first
question,
consistency
of
production
data
for
the
LDDK
adductory
task
/ʌ/
and
abductory
task
/hʌ/
were
compared
using
a
mixed
between‐within
subjects
analysis
of
variance
(ANOVA;
Haynes
&
Johnson,
2009).
Additionally,
interaction
effect,
main
effect,
and
between‐subjects
effect
were
analyzed
and
reported
as
Wilks’
Λ
(Lambda)
values
with
a
probability
level
of
p=0.05.
These
effects
were
analyzed
in
order
to
determine
if
ANOVA
results
were
influenced
by
other
independent
variables,
such
as
chance
or
gender
(Haynes
&
Johnson,
2009).
This
analysis
was
performed
to
determine
if
36
the
two
independent
groups,
the
two
LDDK
tasks,
differed
significantly
on
the
dependent
variable,
the
consistency
of
production
(Haynes
&
Johnson,
2009).
The
second
question
was
answered
through
the
calculation
of
summary
statistics.
Summary
statistical
values
of
mean,
range
and
standard
deviation
were
determined
for
each
LDDK
task,
providing
normative
data
for
adults
between
the
ages
of
60
and
90
years.
The
independent
groups
were
the
two
tasks,
genders,
and
variance,
while
dependent
variables
were
the
summary
values
(Haynes
&
Johnson,
2009).
The
third
question
was
answered
using
the
ANOVA
results
to
determine
the
between‐subjects
effect
of
gender.
The
two
independent
groups
were
male
and
female
participants,
and
the
dependent
variables
were
the
normative
values.
37
CHAPTER
V
RESULTS
Statistical
analyses
revealed
no
statistically
significant
difference
between
LDDK
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/.
Mean,
standard
deviation
and
range
values
were
collected
for
male
and
female
participants
60
to
90
years
of
age,
and
no
statistically
significant
differences
were
found
between
LDDK
consistency
values
for
male
and
female
participants.
The
first
ANOVA
compared
consistency
of
production
data
for
the
LDDK
adductory
task
/ʌ/
and
abductory
task
/hʌ/
in
geriatric
adults
(i.e.,
60
to
90
years
of
age).
Results
revealed
no
statistically
significant
main
effect
for
task
using
an
alpha
of
0.05,
Wilks’
Lambda
=
0.688
F
(1,
85),
p
=
0.409,
and
the
effect
size
was
very
small
(partial
eta
squared
=
0.008).
Results
also
revealed
no
significant
main
effect
for
gender
using
an
alpha
of
0.05,
Wilks’
Lambda
=
0.026
F
(1,
85),
p
=
.872,
and
the
effect
size
was
very
small
(partial
eta
squared
<0.000).
There
was
also
no
significant
interaction
effect
between
gender
and
task
using
an
alpha
of
0.05,
Wilks’
Lambda
=
0.201
F
(1,
85),
p
=
0.655,
the
effect
size
was
very
small
(partial
eta
squared
=
0.002).
The
variances
among
female
/ʌ/
(M
=
0.00535),
female
/hʌ/
(M
=
0.00422),
male
/ʌ/
(M
=
0.00620),
and
male
/hʌ/
(M
=
0.00241)
were
not
significantly
different.
Results
are
summarized
in
Table
1,
Multivariate
Analysis
of
Task.
38
Table 1
Multivariate
Analysis
of
Task
Source
Type III Sum of
Squares
df
Mean Square
F
Sig.
Partial Eta
Squared
Intercept
Gender
Task
Gender * Task
Error
0.002
5.07E-006
0.000
3.890E-005
0.016
1
1
1
1
85
5.607E-005
0.002
5.078E-006
0.000
3.890E-005
9.453
0.026
0.688
0.201
0.003
0.872
0.409
0.655
0.100
0.000
0.008
0.002
The
second
ANOVA
calculated
normative
values
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
for
adults
between
the
ages
of
60
and
90
years.
For
male
participants,
the
normative
value
for
/ʌ/
variance
(i.e.,
the
consistency
of
glottal
syllable
duration)
was
M=
0.00620
(range
=
0.00012‐0.06063ms,
SD=
0.01698).
For
female
participants,
the
normative
value
for
/ʌ/
variance
was
M=
0.00535
(range
=
0.00011‐0.05027ms,
SD=
0.01319).
For
male
participants,
the
normative
value
for
/hʌ/
variance
was
M=
0.00620
(range
=
0.00013‐0.03977ms,
SD=
0.01698).
For
female
participants,
the
normative
value
for
/hʌ/
variance
was
M=
0.00535
(range
=
0.00013‐0.03977ms,
SD=
0.01319).
Results
are
summarized
in
Table
2,
Descriptive
Statistics
for
Consistency
of
LDDK
Production.
39
Table
2
Descriptive
Statistics
for
Consistency
of
LDDK
Production
Consistency
Variable
Task
/ʌ/
Gender
N
Minimum
Maximum
Mean
(M)
Female
25
0.00011
0.05027
0.00535
Standard
Deviation
(SD)
0.01319
Male
20
0.00012
0.06063
0.00620
0.01698
45
0.00011
0.06063
0.00573
0.01482
Female
23
0.00022
0.07529
0.00422
0.01422
Male
21
0.00013
0.03977
0.00858
44
0.00013
0.07529
0.00242
0.00336
Total
Variance
/hʌ/
Total
0.01259
The
third
ANOVA
compared
normative
values
of
LDDK
consistency
of
production
for
female
and
male
participants.
An
independent‐samples
t‐test
was
conducted
to
compare
variance
for
female
/ʌ/
and
male
/ʌ/.
There
was
no
significant
difference
between
female
/ʌ/
(M
=
0.00535)
and
male
/ʌ/
(M
=
0.00620);
t
(43)
=
‐
0.189,
p
=
0.851.
The
magnitude
of
the
differences
in
the
means
was
very
small
(eta
squared
<
0.000).
An
independent‐
samples
t‐test
was
conducted
to
compare
the
variance
for
female
/hʌ/
and
male
/hʌ/.
There
was
no
significant
difference
between
female
/hʌ/
(M
=
0.00422)
and
male
/hʌ/
(M
=
0.00242);
t
(42)
=
0.471,
p
=
0.640.
The
magnitude
of
the
difference
of
the
means
was
very
small
(eta
squared
=
0.003).
An
independent‐samples
t‐test
was
conducted
to
compare
the
variance
for
female
and
male
participants,
both
tasks
combined.
There
was
no
significant
difference
in
scores
for
female
participants
(M
=
0.00481)
and
male
participants
(M
=
0.00426);
t
(87)
=
‐0.869,
p
=
0.852.
The
magnitude
of
the
differences
in
the
means
was
very
small
(eta
squared
=
0.008).
Results
of
gender
comparisons
are
summarized
in
Table
3,
Univariate
Analysis
of
Gender.
40
Table
3
Univariate
Analysis
of
Gender
Consistency
Variable
Variance
Task
N
Mean (M)
Female
Mean (M)
Male
p
/ʌ/
45
0.00535
0.00620
0.640
/hʌ/
44
0.00422
0.00242
0.640
0.003
Total
89
0.00481
0.00426
0.852
0.008
41
eta squared
<0.000
CHAPTER
VI
DISCUSSION
Existing
literature
confirms
the
potential
for
LDDK
to
be
used
as
a
noninvasive
and
inexpensive
means
of
valuating
laryngeal
function.
However,
to
use
LDDK
as
a
predictive
and/or
diagnostic
measure
of
laryngeal
function,
sufficient
data
must
be
collected
from
the
normal
population.
The
data
that
have
been
collected
in
past
studies
are
plagued
by
inconsistencies.
Furthermore,
no
studies
to
date
have
collected
objective
data
on
the
consistency
of
production,
a
measure
identified
in
DDK
studies
to
be
a
valid
assessment
of
neuromotor
coordination
and
control
(Ackermann
et
al.,
1995;
Williams
&
Stackhouse,
2000).
In
pursuit
of
filling
the
LDDK
normative
data
void
present
in
existing
literature,
this
study
posed
three
questions:
1)
Is
there
a
difference
between
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
in
adults
between
the
ages
of
60
and
90
years;
2)
What
are
the
normative
values
for
laryngeal
diadochokinetic
consistency
of
production
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/
in
adults
between
the
ages
of
60
and
90
years;
and
3)
Is
there
a
difference
between
normative
values
of
laryngeal
diadochokinetic
consistency
of
production
for
male
and
female
participants?
First,
this
study
compared
LDDK
consistency
for
the
adductory
task
/ʌ/
and
the
abductory
task
/hʌ/.
No
statistically
significant
differences
were
found
between
consistencies
of
production
of
the
two
tasks
in
the
normal
geriatric
population.
The
absence
of
a
significant
difference
between
the
tasks
may
suggest
that
fine
neuromotor
control
declines
similarly
for
both
adductory
and
abductory
laryngeal
muscles,
or
that
the
sample
size
of
this
study
was
not
large
enough
to
detect
a
significant
effect
for
task.
42
Although
this
suggests
that
only
one
task
may
be
necessary
when
assessing
the
normal
geriatric
population,
both
tasks
should
be
utilized
in
research
until
more
normative
data
are
established
for
young
adult
(20‐40
years
of
age)
and
adult
(40‐60
years
of
age)
populations.
Additionally,
data
for
both
tasks
may
be
important
when
comparing
the
performance
of
disordered
populations
to
normal
populations
(Bassich‐Zeren,
2004).
Second,
normative
values
of
minimum,
maximum,
mean
and
standard
deviation
were
calculated
for
variance.
These
normative
values
were
established
for
male
and
female
participants,
for
each
task,
and
in
total.
This
study
is
the
first
to
objectively
calculate
consistency
of
production.
This
study
strengthens
the
validity
of
LDDK
data
by
collecting
data
for
both
male
and
female
participants,
while
other
studies
sometimes
only
collected
data
on
one
gender
(Leeper
&
Jones,
1991;
Shanks,
1966).
Furthermore,
only
two
studies,
Bassich‐Zeren
(2004)
and
Leeper
et
al.
(1990),
used
both
an
adductory
and
abductory
task,
and
only
Bassich‐Zeren
(2004)
used
the
syllables
/ʌ/
and
/hʌ/.
By
collecting
data
for
both
tasks
and
reducing
the
level
of
oral
involvement
by
using
the
lax,
centralized
vowel
of
/ʌ/
instead
of
the
low,
back,
tense
vowel
of
/ɑ/,
this
study
strengthens
the
validity
of
LDDK
data.
Finally,
this
study
compared
consistency
of
production
of
LDDK
adductory
and
abductory
tasks
between
male
and
female
participants.
No
statistically
significant
differences
were
found
regarding
gender
in
the
geriatric
population.
The
lack
of
significance
of
gender
in
consistency
values
suggests
that
men
and
women
experience
the
anatomical
and
physiologic
effects
of
aging
in
a
similar
fashion
regarding
neuromotor
control
of
the
intrinsic
laryngeal
muscles.
However,
unequal
group
sizes
and
a
small
sample
size
may
have
affected
the
detection
of
significant
effects
for
gender.
43
CHAPTER
VII
LIMITATIONS
The
health
of
participants,
data
collection
procedures,
and
the
recording
equipment
were
all
controlled
in
order
to
maximize
internal
and
external
validity.
However,
limitations
to
this
study
included
sample
size,
participant
diversity,
cognitive,
behavioral,
and
systemic
influences
on
participant
performance,
discontinuity
of
data
analysis
and
the
reliance
on
mean
measures
in
ANOVAs.
Future
research
should
focus
on
confirming
and
expanding
upon
the
results
of
this
study,
as
well
as
addressing
these
limitations.
The
final
sample
size
of
this
study
was
47
individuals,
composed
of
21
men
and
26
women.
No
significant
effects
were
detected
in
data
analysis.
A
larger
sample
size
would
ensure
that
clinically
significant
effects
were
not
missed,
as
well
as
better
represent
the
larynges
of
the
normal
geriatric
population
and
increase
generalizability
of
the
results.
Equal
group
sizes,
male
and
female,
should
also
be
established
in
future
studies.
Unequal
group
sizes
may
have
affected
the
detection
of
clinically
significant
effects
between
male
and
female
groups.
Participant
diversity
was
suboptimal
secondary
to
recruitment
methods.
Investigators
recruited
friends,
family,
friends
of
family,
coworkers
and
community
group
members
to
participate
in
the
study.
The
resulting
sample
did
not
proportionately
represent
the
demographic
diversity
of
the
general
population.
The
external
validity
of
future
research
could
be
strengthened
by
the
recruitment
of
participants
with
the
same
demographics
of
the
population
to
which
the
results
will
be
generalized
(Haynes
&
Johnson,
2009).
44
Cognitive,
behavioral
and
systemic
influences
on
participant
performance
were
limitations
in
regards
to
LDDK
task
performance.
Lack
of
comprehension
of
the
task
was
an
exclusion
criterion,
however
the
possibility
of
cognitive
influence
(e.g.,
anxiety,
confusion,
attention,
and
motivation)
on
task
performance
remained.
Participants
were
asked
to
perform
newly
learned
LDDK
tasks
while
being
recorded.
Cognitive
regulation
of
motoric
actions
(i.e.,
the
intentional
rapid
adduction
and
abduction
of
vocal
folds)
may
have
differed
between
participants
as
they
attempted
perform
the
tasks
for
an
adequate
period
of
time,
affecting
their
rates
and
consistencies.
Furthermore,
behavioral
influences
(e.g.,
alcohol,
tobacco,
and
caffeine
consumption)
can
affect
the
structure
and
function
of
the
larynx
and
respiratory
system
(Stemple,
et
al.,
2010).
Although
participants
were
not
included
if
they
had
a
suboptimal
CAPE‐V
score
and
were
asked
to
refrain
from
consuming
alcohol
prior
to
performing
LDDK
tasks,
undisclosed
and/or
unknown
behavioral
influences
on
laryngeal
function
cannot
be
ruled
out.
Systemic
influences
(e.g.,
respiratory
disease,
allergies,
hormones,
and
pharmaceuticals)
can
also
affect
laryngeal
and
respiratory
system
functioning
(Stemple,
et
al.,
2010).
Such
systemic
influences
are
common
in
the
geriatric
population.
Controlling
for
these
cognitive,
behavioral,
and
systemic
influences
would
increase
internal
validity
of
future
studies,
but
also
decrease
the
generalizability
of
the
results
to
the
general
population.
Discontinuity
of
data
collection
and
analysis
was
the
next
limitation
of
this
study.
This
study
and
the
multi‐year
larger
study
of
which
it
was
a
part
relied
on
analysis
of
data
collected
by
multiple
investigators
in
several
locations
at
different
times.
The
first
three
45
graduate
investigators
of
the
larger
study
collected
data
in
the
field,
converted
audio
recordings
to
.wav
files,
and
analyzed
each
trial
of
each
task
for
rate
of
production.
This
investigator
utilized
the
rate
values
obtained
by
the
other
investigators
and
research
assistants
in
order
to
determine
the
best
trial
(i.e.,
trial
with
the
highest
rate)
for
each
task
for
each
participant.
The
best
trial
was
then
reanalyzed
to
determine
the
measures
of
consistency
necessary
to
answer
the
questions
posed
by
the
current
study.
Although
continuity
of
data
analysis
was
maintained
to
a
great
extent
by
meticulous
documentation
of
the
rate
and
the
time
intervals
used
in
the
original
analysis
of
audio
files
for
rate,
there
were
unforeseen
discontinuities
in
data
collection
and
analysis.
The
voice
analysis
software
did
not
consistently
allow
the
audio
files
to
be
trimmed
to
the
precise
interval
as
the
original
analysis
(i.e.,
0.01‐0.2
deviation
from
the
time
interval
boundaries
used
in
the
rate
analysis).
Thus,
in
future
replications
of
this
study,
it
would
be
advisable
to
analyze
a
data
sample
for
rate
and
consistency
at
the
same
time,
rather
than
reanalyzing
the
data
at
a
later
point
for
consistency
values.
Data
analysis
may
also
have
been
improved
by
calculating
median
values
of
variance
rather
than
mean
values
to
be
used
in
the
three
ANOVAs.
In
situations
where
predictive
normative
data
are
desired
regarding
a
data
set,
median
may
be
a
more
meaningful
measure
than
mean.
Ackermann,
Hetrich,
and
Hehr
(1995)
used
median
syllable
duration
and
variance
of
median
syllable
duration
to
measure
consistency.
The
median
may
allow
for
more
sensitive
detection
of
statistical
significances
than
mean,
increasing
the
future
utility
of
LDDK
for
comparing
disordered
individual
performance
to
normative
data.
In
the
future,
median
and
mean
values
should
be
calculated
and
compared
regarding
sensitivity
and
specificity.
46
Of
these
limitations,
sample
size,
participant
diversity,
discontinuity
of
data
collection
and
analysis,
and
data
measures
are
most
pertinent
for
consideration
in
future
research.
The
sample
size
of
this
study
was
significantly
larger
than
previous
LDDK
studies,
but
a
larger
sample
would
strengthen
the
sensitivity
and
specificity
of
LDDK
normative
data.
Participant
diversity
did
not
proportionately
represent
the
population
to
which
the
results
will
be
generalized,
and
elimination
of
this
limitation
would
strengthen
external
validity
in
future
studies.
Discontinuity
of
data
analysis
did
not
likely
affect
the
internal
validity
of
the
study
significantly,
but
future
studies
should
eliminate
this
limitation
for
both
convenience
and
the
assurance
of
increased
internal
validity.
Mean
and
median
values
should
be
compared
and
used
in
ANOVAs
to
determine
if
one
leads
to
more
sensitive
detection
of
statistically
significant
effects.
Cognitive,
behavioral
and
systemic
influences
could
be
controlled
to
a
greater
extent
than
they
were
in
this
study
to
increase
internal
validity.
However,
any
cognitive,
behavioral
and
systemic
influences
affecting
the
geriatric
participants
of
this
study
undoubtedly
affect
the
general
geriatric
population
as
well.
Thus,
it
stands
to
reason
that
external
validity
would
be
sacrificed
were
these
influences
to
be
controlled.
47
CHAPTER
VIII
IMPLICATIONS
These
preliminary
findings
should
serve
as
the
foundation
on
which
to
continue
evaluating
normative
values
for
LDDK
consistency
of
production.
These
findings
should
be
expanded
upon
and
combined
with
rate
and
strength
of
production
measures.
Future
studies
should
also
address
the
limitations
of
this
study.
In
the
future,
research
should
address:
a)
increasing
the
sample
size;
b)
examining
and
comparing
younger
age
groups
to
the
geriatric
population;
c)
establishing
equal‐sized
male
and
female
groups;
d)
measuring
rate
and
strengths
in
addition
to
consistency;
e)
monitoring
systemic,
behavioral
and
cognitive
influences
on
LDDK
performance;
f)
ensuring
continuity
of
data
analysis;
g)
determining
if
mean
or
median
values
are
more
sensitive
measures
for
detecting
statistical
significance
for
variance;
and
h)
comparing
LDDK
normative
values
with
LDDK
values
obtained
from
individuals
with
neurologic
disease.
Laryngeal
diadochokinesis
has
the
potential
to
be
a
tool
speech‐language
pathologists
can
use
in
the
detection
of
laryngeal
abnormalities.
Performances
revealing
impaired
neuromotor
control
consistent
with
neurologic
diseases
may
allow
for
early
referral
to
neurologists
and
early
treatment
in
the
course
of
progressive
diseases.
48
REFERENCES
Ackermann,
H.,
Hertrich,
I.,
&
Hehr,
T.
(1995).
Oral
diadochokinesis
in
neurological
dysarthrias.
Folia
Phoniatrica
et
Logopaedica,
47,
15‐23.
Ahmad,
K.,
Yan,
Y.,
&
Bless,
D.
(2012).
Vocal
fold
vibratory
characteristics
of
healthy
geriatric
females—analysis
of
high‐speed
digital
images.
Journal
of
Voice,
26(6),
751‐759.
Baken,
R.,
&
Orlikoff,
R.
(2000).
Clinical
Measurement
of
Speech
and
Voice
(2nd
ed.).
Clifton
Park,
NY:
Delmar
Learning.
Bassich‐Zeren,
C.
J.
(2004).
Vocal
dysfunction
in
young­onset
Parkinson's
disease
(Doctoral
dissertation,
University
of
Maryland,
College
Park).
Retrieved
from
http://drum.lib.umd.edu/handle/1903/1823
Boutsen,
F.,
Cannito,
M.
P.,
Taylor,
M.,
&
Bender,
B.
(2002).
Botox
treatment
in
adductor
spasmodic
dysphonia:
A
meta‐analysis.
Journal
of
Speech,
Language
&
Hearing
Research,
45(3),
469‐481.
Canter,
G.
J.
(1961).
An
investigation
of
the
speech
characteristics
on
patients
with
Parkinson’s
disease
(Unpublished
doctoral
dissertation).
Northwestern
University,
Chicago,
IL.
Canter,
G.
J.
(1965).
Speech
characteristics
of
patients
with
Parkinson's
disease,
III:
Articulation,
diadochokinesis,
and
over‐all
speech
adequacy.
Journal
of
Speech
and
Hearing
Disorders,
30,
217‐224.
Consensus
Auditory‐Perceptual
Evaluation
of
Voice
(CAPE‐V).
(2006).
Retrieved
from:
http://www.asha.org/uploadedFiles/ASHA/SIG/03/affiliate/CAPE‐V‐Purpose
‐Applications.pdf.
Fletcher,
S.
G.
(1972).
Time‐by‐count
measurement
of
diadochokinetic
syllable
rate.
Journal
of
Speech
and
Hearing
Research,
15(4),
763‐770.
49
Fung,
K.,
Yoo,
J.,
Leeper,
H.
A.,
Hawkins,
S.,
Heeneman,
H.,
Doyle,
P.,
&
Venkatesan,
V.
M.
(2001).
Vocal
function
following
radiation
for
non‐laryngeal
versus
laryngeal
tumors
of
the
head
and
neck.
The
Laryngoscope,
111,
1920‐1924.
Haynes,
W.,
&
Johnson,
C.
(2009).
Understanding
research
and
evidence­based
practice
in
communication
disorders:
A
primer
for
students
and
practitioners.
Boston,
MA:
Pearsons
Allyn
&
Bacon.
Katz,
J.
(1978).
Handbook
of
clinical
audiology.
Baltimore,
MD:
Williams
&
Wilkins.
Kent,
R.
D.,
Kent,
J.,
&
Rosenbek,
J.
(1987).
Maximum
performance
test
of
speech
production.
Journal
of
Speech
and
Hearing
Disorders,
52,
367‐387.
Kent,
R.
D.,
Kent,
J.,Weismer,
G.,
&
Duffy,
J.
(2000).
What
dysarthrias
can
tell
us
about
the
neural
control
of
speech.
Journal
of
Phonetics,
28,
273‐302.
Leeper,
H.
A.,
&
Jones,
E.
(1991).
Frequency
and
intensity
effects
upon
temporal
and
aerodynamic
aspects
of
vocal
fold
diadochokinesis.
Perceptual
and
Motor
Skills,
73(3),
880‐8.
Leeper,
H.
A.,
Heeneman,
H.,
&
Reynolds,
C.
(1990).
Vocal
function
following
vertical
hemilaryngectomy:
a
preliminary
investigation.
The
Journal
Of
Otolaryngology,
19(1),
62‐67.
Love,
R.
&
Webb,
W.
(1992).
Neurology
for
the
Speech­Language
Pathologist
(2nd
ed.).
Stoneham,
MA:
Butterworth‐Heinemann.
Modolo,
D.,
Berretin‐Felix,
G.,
Genaro,
K.,
&
Brasolotto,
A.
(2011).
Oral
and
vocal
fold
diadochokinesis
in
children.
Folia
Phoniatr
Logop,
63,
1‐8.
50
Ptacek,
P.
H.,
Sander,
E.
K.,
Maloney,
W.
H.,
&
Jackson,
C.
C.
R.
(1966).
Phonatory
and
related
changes
with
advanced
age.
Journal
of
Speech,
Language
&
Hearing
Research,
9(3),
353‐360.
Qiu,
Q.,
&
Schutte,
H.
K.
(2007).
Real‐time
kymographic
imaging
for
visualizing
human
vocal‐
fold
vibratory
function.
Review
of
Scientific
Instruments,
78(2),
024302.
Renout,
K.
A.,
Leeper,
H.
A.,
Bandur,
D.
L.,
&
Hudson,
A.
J.
(1995).
Vocal
Fold
Diadochokinetic
Function
of
Individuals
With
Amyotrophic
Lateral
Sclerosis.
American
Journal
of
Speech
Language
Pathology,
4(1),
73‐80.
Santo
Neto,
H.,
&
Marques,
M.
(2008).
Estimation
of
the
number
and
size
of
motor
units
in
intrinsic
laryngeal
muscles
using
morphometric
methods.
Clinical
Anatomy,
21(4),
301‐306.
Secord,
W.,
Boyce,
S.,
Donohue,
J.,
Fox,
R.,
&
Shine,
R.
(2007).
Eliciting
sounds:
techniques
and
strategies
for
clinicians,
second
edition.
Clifton
Park,
NY:
Delmar.
Shanks,
S.
J.
(1966).
An
investigation
of
the
nature
of
vocal
fold
diadochokinesis
of
adult
subjects
and
of
the
effect
of
pitch,
intensity
and
aging
upon
the
performance
of
this
phonatory
task
(Unpublished
doctoral
dissertation).
Retrieved
from
http://worldcat.org/z‐wcorg.
SPSS
Statistics
Data
Editor
(Version
19).
(2010).
Chicago,
IL:
IBM.
Stager,
S.,
&
Bielamowicz,
S.
(2010).
Using
laryngeal
electromyography
to
differentiate
presbylarynges
from
paresis.
Journal
of
Speech,
Language
&
Hearing
Research,
53(1),
100‐113.
doi:10.1044/1092‐4388.
51
Stathopoulos,
E.,
Huber,
J.,
&
Sussman,
J.
(2011).
Changes
in
acoustic
characteristics
of
the
voice
across
the
life
span:
measures
from
individuals
4‐93
years
of
age.
Journal
of
Speech,
Language
&
Hearing
Research,
54,
1011‐1021.
doi:
10.1044/1092‐4388.
Stemple,
J.
C.,
Glaze,
L.
E.,
&
Klaben,
B.
G.
(2010).
Clinical
Voice
Pathology
(4th
ed.).
San
Diego,
CA:
Plural
Pub.
Stemple,
J.
C.,
Glaze,
L.
E.,
&
Klaben,
B.
G.
(2000).
Clinical
Voice
Pathology
(3rd
ed.).
San
Diego,
CA:
Singular.
Sulica,
L.,
&
Blitzer,
A.
(2006).
Vocal
fold
paralysis.
Berlin,
Ger:
Springer.
Takeda,
N.,
Thomas,
G.,
&
Ludlow,
C.
(2000).
Aging
effects
on
motor
units
in
the
human
thyroarytenoid
muscle.
Laryngoscope,
110(6),
1018‐1025.
Verdolini,
K.,
&
Palmer,
P.
M.
(1997).
Assessment
of
a
"profiles"
approach
to
voice
screening.
Journal
of
Medical
Speech­Language
Pathology,
5(4),
217‐231.
Wang,
Y.,
Kent,
R.,
Duffy,
J.,
&
Thomas,
J.
(2009).
Analysis
of
diadochokinesis
in
ataxic
dysarthria
using
the
motor
speech
profile
programTM.
Folia
Phoniatrica
et
Logopaedica,
61,
1‐11.
Wang,
Y.,
Kent,
R.,
Duffy,
J.,
Thomas,
J.,
&
Weismer,
G.
(2004).
Alternating
motion
rate
as
an
index
of
speech
motor
disorder
in
traumatic
brain
injury.
Clinical
Linguistic
&
Phonetic,
18(1),
57‐84.
Williams,
P.,
&
Stackhouse,
J.
(2000).
Rate,
accuracy
and
consistency:
diadochokinetic
performance
of
young,
normally
developing
children.
Clinical
Linguistics
&
Phonetics,
14(4),
267‐293.
52
Yoss,
K.
A.,
&
Darley,
F.
L.
(1974).
Developmental
apraxia
of
speech
in
children
with
defective
articulation.
Journal
of
Speech
and
Hearing
Research,
17,
399‐416.
Ziegler,
W.
(2002).
Task‐related
factors
in
oral
motor
control:
speech
and
oral
diadochokinesis
in
dysarthria
and
apraxia
of
speech.
Brain
and
Language,
80,
556‐
575.
Zhang,
Z.
(2009).
Characteristics
of
phonation
onset
in
a
two‐layer
vocal
fold
model.
Journal
of
the
Acoustical
Society
of
America,
125(2),
1091‐1102.
53
APPENDIX
CONSENT
FORMS
Informed Consent Form
Project Title: Laryngeal Diadochokinesis: Clinical measurement and age-related values.
You are invited to participate in this research study. The following information is provided in order
to help you to make an informed decision whether or not to participate. If you have any questions
please do not hesitate to ask. You are eligible to participate because you are an adult with no known
laryngeal or neurological disease.
The purpose of this study is to identify your performance on a voice production task. We want to
identify how your performance varies with differences in task complexity. We also want to identify
your overall voice quality and your perception of your voice and swallowing function using
questionnaires. We will compare your performance to other adults of varied age ranges.
Participation in this study will require approximately 20 minutes of your time. All data will be
collected in one session. The study involves two questionnaires and a voice recording. First you will
complete a questionnaire about swallowing symptoms and another about voice symptoms. Each
questionnaire has approximately 30 questions. Then we will record your voice to a CD as you: 1)
repeat an ‘uh’ and ‘huh’ several times, 2) hold out an ‘ah’ and ‘e’ for 5 seconds, 3) read six sentences,
and 4) answer a brief question about yourself. You will be seated approximately 6 inches from a
microphone.
There will be no personal identifying information about you recorded on the CD. The recordings will
be kept in a locked cabinet in 437 Davis Hall at the Indiana University of Pennsylvania. Only the
principal and co-investigators involved in this study will have access to your recording and
questionnaire responses. Your measurements will be considered only in combination with those from
other participants. All data will be held in strict confidence. The information obtained in the study
may be published in scientific journals or presented at scientific meetings but your identity will be
kept strictly confidential. There are no known risks or discomforts associated with this research.
The possible benefit is for you to have access to measurements of your voice and swallowing function.
No other compensation is available for your participation.
Your participation in this study is voluntary. You are free to decide not to participate in this study or
to withdraw at any time without adversely affecting your relationship with the investigators or IUP.
Your decision will not result in any loss of benefits to which you are otherwise entitled. If you choose
to participate, you may withdraw at any time by notifying the Project Director or informing the
person administering the data collection. Upon your request to withdraw, all information pertaining
to you will be destroyed. If you choose to participate, all information will be held in strict confidence.
If you have any questions or concerns, please feel free to contact the principal investigator:
Lori E Lombard, PhD
Professor
Speech-Language Pathology Program
Indiana University of Pennsylvania
203 Davis Hall
Indiana, PA 15705
Phone: 724/357-2450
[email protected]
This project has been approved by the Indiana University of Pennsylvania Institutional Review Board
for the Protection of Human Participants (Phone: 724/357-7730)
54
VOLUNTARY CONSENT FORM:
I have read and understand the information on the form and I consent to volunteer
to be a participant in this study. I understand that my responses are completely
confidential and that I have the right to withdraw at any time. I have received an
unsigned copy of this informed Consent Form to keep in my possession.
Name (PLEASE PRINT)
_________________________________________________________
Signature
______________________________________________________________________
Date
________________________
Phone number or location where you can be reached:
____________________________________
Best days and times to reach you:
_____________________________________________________
I certify that I have explained to the above individual the nature and purpose, the potential
benefits, and possible risks associated with participating in this research study, have
answered any questions that have been raised, and have witnessed the above signature.
__________________________________________________________________________________
Date
Investigator's Signature
55