Transcript Cochlear Implants in Children: What do we know so far?

Peter Flipsen Jr., PhD, CCC-SLP, S-LP(C)
Associate Professor of Speech-Language Pathology
Idaho State University
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COCHLEAR IMPLANTS IN CHILDREN:
WHAT DO WE KNOW SO FAR?
20 YEARS OF U.S. IMPLANTATION
Cochlear implants - around since 1950s.
 FDA approval for use in children over 2 years of
age in 1990.
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Age lowered of 1 year in 2000.
Significant surgery with all the attendant risks.
 Costly.
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Are they living up to their promise in the 20
years since they’ve been widely used?
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THE PICTURE – PRE IMPLANTS
In 1978, Donald Moores wrote of outcomes of
educating children with severe and profound
hearing impairments:

“… an endless stream of children pouring out of
programs for the deaf unable to read at the fifthgrade level, unable to write a simple sentence, unable
to speechread anything but the most common
expressions, and unable to speak in a manner
understandable to any but their immediate family …”
p. 2
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THE PICTURE – PRE IMPLANTS

Sign language:
A viable language system
 Led to the development of a viable culture built
around that language but …
 May severely limit career and life opportunities
 >90% of children born with severe or profound
hearing impairments are born to hearing parents.
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Can mean isolation from family members
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Despite the best-available amplification, spoken
language (understanding and speaking) has been
functionally impractical for this population.
THE PROMISE – THE COCHLEAR IMPLANT
Sometimes called the Bionic Ear.
 Bypasses the outer ear, middle ear, and cochlear
systems
 Directly stimulates the auditory nerve.
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THE COCHLEAR IMPLANT
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THE PROMISE (AND CURRENT FOCUS)
Better outcomes?
 Are these children doing better than they were
before cochlear implants were introduced?

20 years of research to survey.
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Some assumptions here:
Focus on pre-lingually deaf children learning spoken
English
 Comparison group = individuals with severe and/or
profound bilateral losses (will report direct
comparisons where possible).
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FYI - THE MANUFACTURERS
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Three devices approved so far by the FDA:
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1. Cochlear Corporation – Australian
manufacturer of the “Nucleus” implant. First to
develop the multi-channel implant.
 2. Advanced Bionics Corporation – American
manufacturer of the “Clarion” implant.
 3. Med-El Corporation – German manufacturer of
the “Med-El” implant.
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THE COCHLEAR IMPLANT
Should we expect more “typical” outcomes?
 CIs provide “electric hearing” – not acoustic
hearing.

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Directly stimulating the auditory nerve with a series
of electrical pulses
Post-lingually deafened adults say it sounds like
the speaker is pretending to be “Donald Duck” or
“Mickey Mouse”.
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But say they quickly adapt and learn to deal with it.
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FACTORS AFFECTING OUTCOMES
NB: Outcomes continue to be quite variable.
 Lots of different factors have been shown to affect
how a user does with a CI
 1. Factors related to the individual
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Age of implantation
Onset / duration of deafness
Amount of implant experience
Residual hearing
Language mode use
Neural survival / pathway integrity
Presence of other handicapping conditions
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FACTORS AFFECTING OUTCOMES
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2. Surgery related factors
Depth of insertion
 Final electrode position
 Post-operative complications
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3. Technology related factors
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Unilateral vs. bilateral vs. bimodal
Ear choice
Different implants
Different speech processing strategies
Basic channels and virtual channels
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FACTORS AFFECTING OUTCOMES
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4. Intervention related factors
CIs vs hearing aids
 Oral only vs. speech + sign
 Specific therapy approaches
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THESE DEVICES ARE NOT PLUG AND PLAY!
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Auditory training
 Speech training
 Language training
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BUT WHICH OUTCOME?
Is there a best index of success?
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Probably depends on who you ask.
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Several possibilities:
Hearing acuity / sensitivity?
 General auditory skills?
 Speech perception?
 Language comprehension?
 Speech production?
 Expressive language?
 Academic skills?
 Self-esteem?
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HEARING ACUITY OUTCOMES
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The best available hearing aids might bring
thresholds into the moderate loss range.
Thresholds for CIs can potentially be in the
normal range
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usually set at the edge of normal or just into the mild
loss range during mapping.
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Little debate here.
GENERAL AUDITORY SKILLS

MAIS and IT-MAIS
“Meaningful Auditory Integration Scale” and the
Infant and Toddler version.
 Commonly used; looks at “… spontaneous listening
behaviors in everyday situations.”
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Interview format to obtain parent report.
 http://www.bionicear.com/printables/itmais_brochure.pdf
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More than just hearing; how does the individual
respond in a sound-based world?
GENERAL AUDITORY SKILLS
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McConkey Robbins et al (2004) evaluated the use
of the IT-MAIS
Followed 3 groups of children (107 total) who rec’d
implants for a one year period after implantation.
 All rec’d implants by age 3 years, some as early as 12
months.
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SPEECH PERCEPTION SKILLS
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Many different measures are used.
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Closed set vs. open set
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In quiet vs. in noise
As with hearing aids, better results in quiet.
 Ability to deal with noise improves with experience.
 Being able to set sensitivity on device allows for better
control over noisy settings but only for conversation
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Single words vs. connected speech
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See changes early in closed set ability
 Ultimate goal = open set (mimics real life)
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SPEECH PERCEPTION
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Studies generally show much better outcomes
than with HAs
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Hard to compare studies because different tests are
used
No clear consensus on the best test.
Individual tests only useful for short periods of time.
 Many individuals eventually “ceiling out”.
 Not clear how to interpret findings when we shift
tests.
 Makes it difficult to track long-term changes.
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WANG ET AL (2008)
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Proposed using a battery of commonly used tests.
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Created a composite score called the SRI-Q (speech
reception in quiet).
Followed two groups every 6 months for 3 years.
188 children with sensorineural hearing loss who
rec’d CIs at about age 2 years
 97 age-matched normal hearing children.
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Findings suggest the SRI-Q allows us to track
changes over longer periods of time
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Children with normal hearing achieved ceiling scores
earlier.
WANG ET AL (2008) FINDINGS
RECEPTIVE LANGUAGE
Not examined very much so far.
 Speech perception tests don’t test understanding.
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Baldassari et al (2009) reported on 36 children who
received CIs from age 11 to 70 months (mean = 33
months).
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All receiving AV therapy at a private school.
Tests given on average about 30 months postimplantation.
BALDASSARI ET AL (2009)
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Three tests given:
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1. Test of Auditory Comprehension (TAC).
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Normed on hearing impaired children using HAs.
2. Bracken Basic Concept Scale (BBCS)
Single word task
 Normed on normal hearing children.
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3. Test of Auditory Comprehension of Language (TACL)
Normed on normal hearing children.
 Subtests for comprehension of vocabulary, grammatical
morphemes, and elaborated sentences.
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BALDASSARI ET AL (2009)
TAC outcomes clearly better than for children with
hearing aids.
 BBCS and TACL outcomes relative to children with
normal hearing were in the normal range in many
cases.
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Age-equivalent scores not the best choice
BUT smallest “gap” seen in grammatical morphemes?
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Usually a problem for hearing children with language
impairments.
PROSODIC SKILLS
A classic area of difficulty for individuals with hearing
impairment.
 An early developing skill area for normal hearing
children.
 Lenden & Flipsen (2007) examined this.
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6 children recorded in conversation every 3 months for up
to 2 years (40 total samples).
All had received implants before age 3 years.
Began with 25-42 months of implant experience.
Rated utterances using “Prosody Voice Screening
Profile” (PVSP).
% Approp.
Range
# Samples
Passed
# Samples
Borderline
# Samples
Failed
Phrasing
97.1 (4.3)
86-100
36
4
0
Rate
88.4 (10.0)
60-100
22
13
5
Stress
48.2 (26.9)
0-96
2
5
33
Loudness
92.4 (10.8)
56-100
32
2
6
Pitch
97.6 (4.3)
80-100
38
2
0
Laryngeal
Quality
87.3 (15.0)
36-100
24
7
9
Resonance
Quality
10.4 (20.8)
0-84
0
1
39
LENDEN & FLIPSEN (2007)
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Most areas showed a high % of appropriate utterances.
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Most samples sounded prosodically like normal speech.
Some areas of difficulty.
Resonance quality = poorest.
 Some utterances resembled “cul-de-sac” resonance but
subjectively not as bad as classic speech pattern of the deaf.
 Difficulties with stress tended to be misplaced syllable
stress.
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EMERGENCE OF SPEECH
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1. Does the infant’s voice sound pleasant?
2. Does the infant produce sounds other than crying?
3. Does the infant produce sounds in reaction to an auditory stimulus
(not necessarily speech)?
4. Does the infant produce sounds of varying intonation?
5. Does the infant produce vowel-like sounds, such as: /a/, /e/,/i/,?
6. Does the infant produce different consonant-vowel combinations?
7. How often does the infant produce consonant-vowel combination?
8. Does the infant reduplicate syllables?
9. Does the infant try to repeat the word he heard or a part of it?
10. Does the infant use a permanent sequence of sounds in relating to
a certain object?
11. Does the infant use permanent sequences of sounds in relating to
certain objects?
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Kishon-Rabin et al (2005) developed the PRISE
(PRoduction Infant Scale Evaluation). Analog to
the IT-MAIS. Parent interview questionnaire.
KISHON-RABIN ET AL (2005)
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Administered the PRISE to two groups:
24 hearing-impaired infants
 Rec’d CIs at 11-29 months (mean = 18.9 months)
 Tested pre-implant and following 2-16 months of
implant experience (mean = 8 months)
 163 normal hearing infants
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Converted scores out of 44 to %.
 Compared relative to age and amount of
implant experience
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KISHON-RABIN ET AL (2005)
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Clearly behind age expectations both before and after
implantation.
Scores near normal when evaluated against amount of
implant experience.
SPEECH SOUND ACCURACY – SINGLE
WORDS
Flipsen, Blaiss, & Parker (2007) looked at
performance on the GFTA-2.
 16 children with CIs (4M; 12F)
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Age at implantation = 1;2 – 8;4 (mean = 3;5).
 Chronological Age = 4;8 – 11;1 (mean = 7;11).
 Implant experience = 1;0 – 7;10 (mean = 4;5).
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FLIPSEN, BLAISS, & PARKER (2007)
Relative to CA, 5/16 children (31%) achieved
standard scores within 1.5 standard deviations of
their age group (i.e., at least 78).
 Relative to implant experience, 11/16 children
(69%) achieved standard scores within 1.5
standard deviations of their age group.
 Raw scores (# of errors) were significantly
correlated with amount of implant use
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r = -.73, p = .001.
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INTELLIGIBILITY
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How well you can make yourself understood.
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Moores (1978) said:
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Ultimate goal of communication.
“…unable to speak in a manner understandable to any but
their immediate family …”
Gold (1980) said:
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“… only about 20% of the speech output of the deaf is
understood by the ‘person on-the-street’…”
INTELLIGIBILITY
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Flipsen (2008) summarized several studies of CI users
which used the Speech Intelligibility Rating Scale
(SIR).
Category Rating Criteria
5
Connected speech is intelligible to all listeners. Child is understood easily in
everyday contexts.
4
Connected speech is intelligible to a listener who has a little experience of a deaf
person’s speech.
3
Connected speech is intelligible to a listener who concentrates and lip-reads.
2
Connected speech is unintelligible. Intelligible speech is developing in single
words when context and lip-reading cues are available.
1
Connected speech is unintelligible. Pre-recognizable words in spoken language.
Primary mode of communication may be manual.
1 year post
implant
Study
3 years post
implant
5 years post
implant
1
Mean Age SIR
of
3+
Implant
91%
3;6
2
3;9
17%
8%
2%
71%
48%
25%
79%
66% 34%
3
3;9
13%
0%
0%
58%
17%
0%
66%
33% 33%
4
4;4
11%
0%
0%
63%
13%
3%
91%
55% 46%
5
4;8
6
5;3
7
Not
specified
26%
SIR
4+
SIR
=5
SIR
3+
SIR
4+
SIR
=5
SIR
3+
36%
0%
94%
94%
41%
100% 100
%
3%
3%
69%
14%
7%
10 years
post implant
SIR SIR SIR SIR SIR
4+
= 5 3+
4+
=5
78%
84% 68%
41%
83%
47% 27% 83% 73%
37%
83%
44% 33%
FLIPSEN (2008)
Concluded that these were clearly better outcomes
than with hearing aids.
 Younger age of implantation = better outcome.
 Improvement continues along with implant experience.
 Progress continues in many cases for up to 10 years
post-implantation.
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EXPRESSIVE LANGUAGE OUTCOMES
Like receptive language, this area has also not
received much attention.
 Geers (2004) reported data on 133 children implanted
2;0 – 5;2 (mean = 3;6).
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Follow-up testing at about age 9 years.
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Testing included several language measures including the
Index of Productive Syntax (IPSyn).
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4-7 years of implant experience.
Measures syntactic skill from conversational speech.
Also measured Performance IQ from WISC.
GEERS (2004)
Normal range performance IQ.
 35-52% had normal range IPSyn performance.
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Relative to chronological age matches (not amount of
implant experience).
Earlier implantation appears to improve the chances
of having normal expressive syntax skills.
READING OUTCOMES
ARCHBOLD ET AL (2008)
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British study of 105 children with CIs
Implanted from 1;4 to 6;11 (mean = 4;2)
 Evaluated at 7 years post-implant
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CA = 8;4 – 13;11 (mean = 11;1)
Used Edinburgh Reading Test (normed on normal
hearing children)
 Reported “gap” between reading age and CA
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Reported a significant, strong (r = -.74)
correlation between the “gap” and age of
implantation.
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Earlier implantation = closer to “normal”
SELF-ESTEEM OUTCOMES
PERCY-SMITH ET AL (2008)
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Long history of studies of children with hearing
impairment having poor self-esteem.
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Not surprising given other poor outcomes.
Danish study of 164 children with CIs
Implanted at 6 months to 17 years (mean = 4 years)
 Studied at age 2-17 years
 Compared to findings from 2000+ normal hearing
children (separate study)
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PERCY-SMITH ET AL
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Used a parent questionnaire asking:
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(2008)
how well they were “getting along” in school
how well they were doing academically
About the number of good friends they had
Whether they had been bullied or were bullying
others in school
For ratings of their children (7 point scale) on several
descriptive terms relating to self-esteem
Concluded that there were essentially only minor
differences.
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Clearly a noticible improvement over where these
children would have been with sign and/or hearing
aids.
PROBLEMS? REMAINING ISSUES?
Speech in noise and localization?
 Surgical risks?
 Device failure?
 How early should we implant?
 The bilateral question?
 Which ear?
 Specific devices and/or processors?
 Specific approaches to intervention?
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BIGGEST ISSUE: Can’t reliably predict
outcomes very well for any given individual.
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SUMMARY
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Not perfect however.
Clearly better outcomes from:
Earlier implantation
 Longer device use
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Still more to learn especially because ….
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We now see more implantations in those with either
more residual hearing or other handicapping
conditions.
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It would appear that cochlear implants provide
significantly improved outcomes compared to
older technology (i.e., hearing aids).
REFERENCES
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Baldassari, C.M., et al (2009). Receptive language outcomes in children after cochlear implantation.
Otolaryngology - Head and Neck Surgery, 140, 114-119.
Flipsen, P., Jr. (2008). Intelligibility of spontaneous conversational speech produced by children with
cochlear implants: A review. International Journal of Pediatric Otorhinolaryngology, 72(5), 559-564.
Flipsen, P., Jr., Blaiss, J., & Parker, R. (2007, November). Performance of children with cochlear implants
on the GFTA. Poster presentation at the Annual Convention of the American Speech-Language-Hearing
Association (ASHA), Boston, MA.
Geers, A. (2004). Speech, language, and reading skills after early cochlear implantation. Archives of
Otolaryngology, Head and Neck Surgery, 130, 634-638.
Gold, T. (1980). Speech production in hearing-impaired children. Journal of Communication Disorders, 13,
397-418.
Kishon-Rabin, L., et al (2005). Prelexical vocalization in normal hearing and hearing-impaired infants
before and after cochlear implantation and its relation to early auditory skills. Ear and Hearing, 26 (4,
Suppl.), 178-298.
Lenden, J. M., & Flipsen, P., Jr. (2007). Prosody and voice characteristics of children with cochlear implants.
Journal of Communication Disorders, 40(1), 66-81.
McConkey Robbins, A., et al (2004). Effect of Age at Cochlear Implantation on Auditory Skill Development
in Infants and Toddlers. Archives of Otolaryngology, Head and Neck Surgery, 130, 570-574.
Moores, D. F. (1978). Educating the deaf. Psychology, principles, and practices. Boston, MA: Houghton
Mifflin.
Percy-Smith, L., et al (2008). Self-esteem and social well being of children with cochlear implants compared
to normal-hearing children. International Journal of Pediatric Otorhinolaryngology, 72, 1113-1120.
Wang, N.-Y., et al (2008). Tracking Development of Speech Recognition: Longitudinal Data From
Hierarchical Assessments in the Childhood Development After Cochlear Implantation Study. Otology &
Neurotology, 29, 240-245.
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Archbold, S., et al (2008). Reading abilities after cochlear implantation: The effect of age at implantation on
outcomes at 5 and 7 years after implantation. International Journal of Pediatric Otorhinolaryngology, 72,
1471-1478.
QUESTIONS?
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