Introduction (1)
• In this series of lectures we will examine
the anatomy and functional physiology of
the structures that together can be
manipulated to create coordinated
patterns of vocal tract shape.
• These patterns of changing vocal tract
shape are know as the “articulatory”
patterns of speech production.
Speech Physiology
Articulation and Resonance
Lecture 1
Dr Robert H. Mannell
Department of Linguistics
Macquarie University
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Introduction (2)
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Introduction (3)
• When we refer to the “vocal tract” we are
usually referring to the space (or cavity)
above the glottis (known as the “supraglottal” cavity)
• This cavity consists of the oral and nasal
cavity.
• When we talk about changing patterns of
vocal tract shape we are always referring
to the shape of the cavity.
• Changing the shape and/or position of
certain organs changes the shape and
size of the supra-glottal cavity.
• Some of the structures around the vocal
tract cavity are (for the most part) passive
walls of the tract. These include the hard
palate of the roof of the mouth, most of the
surrounding walls of the nasal cavity, and
the back wall of the pharynx.
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Introduction (4)
4
Introduction (5)
• Other structures in the supra-glottal vocal
tract can be manipulated by various
muscles to change their position and shape.
This results in changes in the size and
shape of the supra-glottal cavity.
• Such structures are referred to as
“articulators” (or “active articulators”) as
their position and shape can be “articulated”
(or finely controlled).
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The major active
articulators of the
vocal tract are:1. Tongue
2. Lips
3. Velum (soft palate)
4. Mandible (jaw)
Hardcastle (1976)
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1
Introduction (6)
Vocal Tract Tissues (1)
Here we can see an
anterior (front) view
of the oral cavity
showing the lips,
tongue, teeth and
hard and soft palate
(and a few additional
features).
Seikel et al (1997)
There are four major types and all can be
found in the vocal tract. They are:•
•
•
•
Epithelial
E
ith li l titissue
Connective Tissue
Muscle Tissue
Nervous Tissue
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Vocal Tract Tissues (2)
Vocal Tract Tissues (3)
Epithelial tissues: cover the surface of the
body, cover and line internal organs, include
the glands. Their functions include
protection, secretion, absorption and
excretion In the vocal tract they include:
excretion.
include:-
Connective tissues: support, bind and
protect body structures.
Bones: In the vocal tract they include the
j , hard palate
p
and
bones of the skull,, jaw,
nasal cavity which underlie the shape of
these structures. Bones also provide points
of origin for many of the muscles involved in
articulation. The hyoid bone in the neck is
also the point of origin of a number of
muscles involved in articulation.
a. skin on the face surrounding the lips
b. mucous membrane covering the lips, the
inner surfaces of the oral and nasal
cavities and the surface of the tongue.
c. salivary glands
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Vocal Tract Tissues (4)
Vocal tract Tissues (5)
Connective tissues:
Cartilage is a lighter, more flexible structural
tissue than bone. As we already know, it
y
constitutes the main structures of the larynx.
It also constitutes the structural component
of the epiglottis (which is not used as an
articulator in speech – except perhaps in
pre-linguistic sounds of neonates). There
are also some cartilaginous structural
components in the nasal cavity.
Connective tissues:
There are a number of different types of
fibrous tissue that is quite flexible but can
p
structural component
p
of
also be an important
many organs. In the vocal tract, the most
important of these is a central fibrous
“septum” running along the centre of the
tongue and providing the point of origin of
certain tongue muscles.
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12
2
Vocal Tract Tissues (6)
Vocal tract Tissues (7)
Connective tissues:
• Ligaments connect bone to bone, bone to
cartilage and cartilage to cartilage. There
are manyy of these but perhaps
p
p the most
important in the articulatory system are the
ligaments (one each side of the jaw) that
connect the condylar process of the jaw to
the Zygomatic arch of the skull.
• Tendons connect muscles to bone,
cartilage and some fibrous structures.
Connective tissues:
Loose connective tissue lies below the skin
and mucous membrane in most parts of the
vocal tract.
tract For example,
example it makes up part of
the mass beneath the mucous membrane of
the soft palate, the nasal cavity and the
region below the front of the tongue.
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Vocal Tract Tissues (8)
Vocal tract Tissues (9)
Teeth are unique in the body. They are not
considered to be bones as they differ
significantly from bones in certain ways
(they are harder than bones and their
structure and protein content is different). In
the vocal tract the upper teeth provide
passive articulatory targets for some speech
sounds. They also contribute to the overall
shape of the oral cavity.
Muscles: Muscles are often described in
terms of:a) Muscle Point of origin: The attachment
point at the more massive
massive, less
moveable end of the muscle. In the
supra-glottal vocal tract this is usually a
bone, but some muscles in the tongue
originate from a central fibrous septum.
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Vocal tract Tissues (10)
Vocal Tract Tissues (11)
b) Muscle point of insertion: the other end
of the muscle (it might be a lighter, more
moveable bone than the point of origin, or
it might insert into another muscle)
muscle). For
example, some tongue muscles insert
into other muscles.
• For a number of articulatory organs its
convenient to talk about intrinsic muscles
and extrinsic muscles.
• Intrinsic muscles are found wholly within
the structure and may change its shape.
• Extrinsic muscles insert into the structure
but have their point of origin elsewhere.
They can change both shape and position.
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3
Vocal Tract Tissues (12)
The skull (1)
• There is a large network of cranial nerves
that attach to the various structures of the
head including the vocal tract articulators.
These include both motor neurons and
sensory neurons. They will be dealt with in
more detail later in the semester.
• A motor unit is a group of muscle fibres
that are controlled by a single motor
neuron fibre.
• In the following two images we examine
the front and back of the skull (plus the
jaw).
• Several bones of the skull cover brain
lobes of the same name.
• A process is a prominent projection on a
bone.
• A foramen is an opening through the bone
for blood vessels, nerves or ligaments.
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The skull (2)
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The skull (3)
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The nasal cavity (1)
The nasal cavity (2)
• In the following image we can see the bone
and cartilage structures of the nasal cavity.
• The superior (upper) surface is a sinus filled
part of the skull.
p
• The inferior (lower) surface consists of two
bones of the hard palate and the tissue of
the soft palate.
• These structures are covered by loose
connective tissue and mucous membrane.
• The structures of the nasal cavity, with the
exception of the soft palate (velum) are
fixed in shape and dimensions and thus
fixed acoustic (resonance) characteristics.
characteristics
• Their resonance characteristics are only
affected by degree of velum opening and
by tissue swelling during a head cold, hay
fever or similar affliction.
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4
The nasal cavity (3)
The hard palate (1)
• In the next slide we can see the bony
structure of the hard palate.
• Like much of the vocal tract, structures are
mirrored on the left and right side.
• The bones are covered by loose connective
tissue which is in turn covered by mucous
membrane.
• The suture down the middle, if it fails to join
during foetal development, results in a cleft
palate.
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The hard palate (2)
The jaw (1)
• The jaw is a horseshoe shaped bone.
• It is connected by ligaments, at the head
of the condylar process, to the zygomatic
arch of the skull forming a hinge.
hinge
• Muscles attached to various parts of the
jaw are responsible for several degrees of
movement.
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The jaw (3)
The jaw (2)
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The jaw (5)
The jaw (4)
• In speech the relevant dimensions of
movement are jaw raising (for many
lingual (tongue articulated) consonants
and for high vowels) and jaw lowering (for
low vowels).
• The muscles of jaw lowering are assisted
by the action of gravity, which has quite a
significant effect on the relatively massive
body of the jaw.
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The jaw (6)
The tongue (1)
• The jaw is the most massive (weighs the
most) of the four major articulators and so it
is also the slowest moving articulator. In
other words, it has the highest degree of
inertia.
• The jaw is also the least important of the
four major articulators. This can be seen by
the fact that its possible to speak fairly
clearly (although not completely clearly) with
teeth clenched (ie. with the jaw up).
• In the next slide we can see that the
tongue consists of intrinsic muscles that
are wholly within the tongue and extrinsic
muscles that originate outside the tongue
and insert into the body of the tongue.
• Note that in the next slide the more Latinlike spellings of these muscles are used.
The alternative non Latinate spellings are
also acceptable.
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The tongue (2)
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The tongue (3)
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The tongue (4)
The tongue (5)
• In the next image we see greatly simplified
vector representations of the direction of
action of the extrinsic muscles (plus the
intrinsic longitudinal superior muscle)
muscle).
• The arrows indicate the direction that the
tongue body will move with the contraction
of a particular muscle (all else being
equal). Extrinsic muscles pull the tongue
towards their point of origin.
• It should also be noted that in the case of
the longitudinal superior muscle the points
of origin and insertion isn’t obvious.
• The muscle extends from the back of the
tongue to the tip of the tongue.
• The more massive anchor point is regarded
as the point of origin. As the back of the
body of the tongue is more massive than
the tip of the tongue contraction of this
muscle will mostly move the tip backwards.
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The tongue (6)
The tongue (7)
• In the next image we see another stylised
diagram of the relative locations of the
muscles (with exaggerated separation of the
muscles). We can see all of the intrinsic
muscles and two of the extrinsic muscles.
• The transversus muscle originates in the
central fibrous septum.
• The verticalis muscle can be said to
originate in the less movable base of the
tongue.
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The tongue (8)
The tongue (9)
• The next diagram has removed the
intrinsic muscles of the tongue and only
shows the course of the extrinsic muscles.
These muscles fan out as they reach their
point of insertion in the tongue. This is
shown more accurately here than in the
vector diagram whilst the vector diagram
shows more clearly the effect of muscle
contraction.
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7
The tongue (10)
The tongue (11)
• The next 5 slides describe and illustrate
seven articulatory dimensions or
parameters that result in phonetically
important tongue articulations
articulations.
• For further details on this model you are
referred to:W.J Hardcastle, 1976, Physiology of Speech Production,
Academic Press, London, pp 100-106
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The tongue (12)
44
The tongue (13)
45
The tongue (14)
46
The tongue (15)
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8
The tongue (16)
The tongue (17)
• As we can see (particularly in slide #14),
the body and the tip of the tongue can to a
fair extent be moved independently of
each other
other. Its possible,
possible for example,
example to
move the tip back whilst moving the body
forward. The tongue tip, being lighter (less
inertia), can move and change direction
more rapidly then the tongue body.
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The pharynx (1)
The pharynx (2)
• The pharynx can be divided into the oro-pharnx
and the naso-pharynx. The naso-pharynx is the
region at and above the point where the velum
closes. The oro-pharynx is below that point.
• The oro
oro-pharynx
pharynx can be considered and
articulatory organ, but in most cases its a passive
articulatory organ. The active articulator is the
root of the tongue. eg. for low vowels the place of
greatest constriction is the oro-pharynx and the
constriction is created by the back of the tongue
bulging back towards the rear of the pharynx.
• In some languages (eg. Arabic) the oropharynx is an active articulator for
pharyngeal and pharyngealised consonants.
• The next two images show the location of
the main pharyngeal constrictor muscles,
the stylopharyngeus, and the superior,
middle and inferior pharyngeal constrictor
muscles.
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The pharynx (3)
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The pharynx (4)
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Further Reading
References
• Clark, J., Yallop, C. & Fletcher, J. (2007), An introduction
to phonetics and phonology, 3rd. edition, Blackwell,
Oxford (pages 84-90 and Section 7.17)
• J.A. Seikel, D.W. King and D.G. Drumright, (1997),
Anatomy and Physiology for Speech,
Speech Language,
Language and
Hearing, Singular, San Diego (or a more recent edition of the
same text)
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The following books were used as sources
for materials used in this lecture:• W.J Hardcastle, 1976, Physiology of Speech Production, Academic
P
Press,
London
L d
• J.A. Seikel, D.W. King and D.G. Drumright, 1997, Anatomy and
Physiology for Speech, Language, and Hearing, Singular, San
Diego
• D. Shier, J. Butler and R. Lewis, 2004, Hole’s Human Anatomy and
Physiology, 10th edn., McGraw Hill, Boston.
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