Multimodal Assessment and Speech Perception
Outcomes in Children with Cochlear Implants or
Hearing Aids
Karen Iler Kirk, Ph.D., CCC-SLP*
Shahid and Ann Carlson Khan Professor and Head
Department of Speech and Hearing Science
University of Illinois at Urbana-Champaign
Work supported by NIDCD Grants R01 DC 008875 and P50 DC000242
DISCLOSURE: Test materials described in this presentation are licensed to G.N. Otometrics through
The University of Iowa
Collaborators
—  Children’s Memorial Hospital,
—  The University of Iowa
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Karen Iler Kirk, PhD (PI)
Lindsay Prusick, AuD
Virginia Driscoll, MA
Nathaniel Wisecup, BA
Lauren Diamond, BA
Lauren Dowdy, BA
Ruth Flaherty, BA
—  House Research Institute,
Los Angeles
—  Laurie Eisenberg, PhD (PI)
—  Amy Martinez, MA
—  Dianne Hammes Ganguly, MA
Chicago
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Nancy Young, MD (PI)
Susan Stentz, AuD
Lisa Weber, AuD
Iguehi James, MPH
—  Washington State University
—  Brian French, PhD (PI)
—  Chad Gotch, MS
—  University of Illinois
—  Michael Novak, MD
—  Jean Thomas, AuD
—  Michael Hudgins, BA
Introduction
—  Listeners must extract linguistic message from highly
variable acoustic speech signal
—  Variability introduced by:
—  Talker characteristics - gender, age, dialect and speech rate
—  Environment – noise, reverberation
—  Presentation format – A-only vs. Auditory-plus-Visual
—  Linguistic characteristics
—  Word frequency – how often words occur in language
—  Lexical Density – the number of phonemically similar words or lexical
neighbors
Multimodal Lexical Sentence Test (MLST-CTM)
—  21 lists of 8 sentences
—  10 talkers
—  3 key words per sentence
—  Key words in each sentence drawn from the same lexical category
—  Strong Psychometric principles
—  Lists are reliable and equivalent within each format: V, A, AV
Purposes
—  To examine performance in quiet in children with cochlear
implants or hearing aids
—  To examine performance in noise as a function of
—  Signal-to-Noise Ratio (SNR)
—  Group
—  CI only
—  CI + HA
—  To evaluate AV enhancement as a function of SNR
Assessing Performance in Quiet
Participants (N=68)
CI Users
(n = 32)
HA Users
(n = 27)
CI+HA Users
(n=9)
9.86 years
8.92 years
9.61 years
.18 years
1.07 years
0 years
2.93 years
3.18 years
6.67 years
Profound - 20*
Unknown - 12
Mild - 9
Moderate – 15
Severe - 2
Profound - 1
CI: Profound
HA: Severe -8
Profound -1
Receptive Vocabulary
Age
9.32 years
9.73 years
9.63 years
Gender
16 males
16 females
16 males
11 females
7 males
2 females
Mean Age at Test
Mean Age at Onset
Mean Age Fit
(current sensory aid)
Hearing Loss
Classification
(4 frequency PTA)
*Pre-implant thresholds
Methods
—  All MLSTTM lists administered twice
—  Every participant tested in all 3 presentation formats
—  1/3 Visual Only
—  1/3 Auditory Only
—  1/3 Auditory + Visual
—  Additional auditory only testing
—  Isolated word recognition (PBK)
—  2 lists of HINT-C
—  Procedures
—  Speech presented at 60 dB SPL in quiet
—  Verbal responses scored as percent correct
—  Receptive Vocabulary assessed using PPVT
Results: Multimodal Sentence Recognition
Auditory-Only Speech Recognition
Performance in Noise: CI Participants (n=20)
CI (n=14) CI+HA (n=6) Mean Age at Test 12.1 yrs 9.8 yrs Mean Age at
Implantation
3.2 yrs 5.5 yrs Mean Length of
Device Use 9.9 yrs 4.5 yrs Type of CI Freedom (n=5)
CI24M (n=5)
CI24R (n=1)
Countour (n=3) Hybrid L24 (n=2)
Contour (n=1)
Freedom (n=2)
CI512 (n=1) Procedures
—  Speech administered at 60 dBA SPL
—  Each participant tested in A and AV formats
—  Quiet
—  SNRs: -5, 0, +5, +10
—  2 lists per condition (2 formats X 4 SNRS = 8 lists)
—  Verbal responses scored as % key words correct
—  Logistic regression computed to estimate Speech Recognition
Threshold
Results
100
90
Percent Correct
80
70
60
50
40
A
30
AV
20
10
0
0
5
10
Q
0
5
CI
10
CI+HA
Signal-to-Noise Ratio
Q
Results: SRT
CI + HA
100.0
100.0
90.0
90.0
80.0
80.0
70.0
70.0
Percent Correct
Percent Correct
CI
60.0
50.0
40.0
30.0
60.0
40.0
30.0
20.0
20.0
10.0
10.0
0.0
0.0
0
5
10
0
5
10
Signal-to-Noise Ratio
Signal-to-Noise Ratio
A only
A +V
A
AV
50.0
CI
2.8 dB
-8.5 dB
CI + HA
-0.6 dB
-13.1 dB
Audiovisual Gain
Ra = (AV-A)/(100-A)
—  Relative gain in accuracy in AV condition relative to A only
—  Used by Lachs et al. (2001) to examine AV speech perception
in children with CIs
Ra by SNR
0.70
0.60
0.50
Ra
0.40
0.30
0.20
0.10
0.00
0
5
10
Signal-to-Noise Ratio
Q
Conclusions
—  The MLST-CTM
—  Incorporates "real-world” stimulus variability
—  Multiple talkers
—  Different presentation formats
—  Is a more sensitive measure of performance than traditional tests
—  The addition of visual cues enhances speech perception
—  Largest improvements at poorer signal-to-noise ratios
Not all children show similar benefit
—  Enhancement is larger for children with acoustic low frequency hearing
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—  Future testing to examine factors related to AV enhancement