Pediatric Image-Guided Cochlear Implant Programming

Although children with cochlear implants (CIs) have significantly improved speech, language,
and reading outcomes relative to previous generation CI recipients, too many pediatric CI
users still display persistent speech, language, and reading difficulties despite early
implantation and early intervention. Children with CIs typically lag behind their peers with
normal hearing (NH) by 1 or more years on measures of speech, language and/or reading. Though
these persistent delays can be attributed in part to a period of auditory deprivation prior
to implantation, increasing evidence suggests that a degraded CI signal is also implicated in
poorer development of auditory, speech, language, and reading skills for pediatric CI
recipients. A related developmental path to reading also disrupted from the degraded CI
signal is phonological awareness (PA) because PA is predicated, in part, on speech
recognition.

A procedure developed by Noble and colleagues, image-guided CI programming (IGCIP),
significantly improves auditory function, speech recognition, and distally, receptive
language abilities for adult CI users. The investigators have preliminary evidence that
pediatric CI recipients also significantly benefit from IGCIP. But there is a need to
systematically investigate IGCIP in children to determine whether this individualized
intervention yields a) associated benefits in auditory function and b) related improvements
in speech, language, PA and/or reading. Thus, our primary goal is to evaluate the effects of
IGCIP on auditory function, speech recognition, PA and reading, as well as speech and
language abilities in pediatric CI recipients within the context of a double blind, waitlist
controlled randomized clinical trial (RCT). The investigators will obtain psychophysical
estimates of auditory function and speech recognition, PA, reading, speech, and language
abilities for 72 pediatric CI users in a baseline assessment and repeated time points for 24
months to test the impact of IGCIP. The investigators will examine the immediate (short-term)
and longer-term effects over a 2-year period by comparing outcomes between groups for those
randomly assigned to immediate (n = 36) or deferred (n = 36) IGCIP using a waitlist control
study design (deferred IGCIP). The initial comparison will be for immediate and deferred
IGCIP groups at 2, 6, and 12 months. The deferred group will then receive the IGCIP
intervention and both groups will be followed for an additional 12 months (total enrollment
for 24 months). The proposed research includes the following aims and specific hypotheses:

Aim 1: Auditory function. The investigators will compare auditory function and speech
recognition of the immediate and waitlist control participants. Hypothesis 1a: There will be
significant positive short-term gains (2-6 months) in spectral and/or temporal resolution as
well as speech recognition—particularly in noise—for children immediately receiving IGCIP as
compared to waitlist controls. This hypothesis will be tested by comparing the difference in
the amount of change in scores within-subjects (pre- to post-IGCIP gain) between the groups
(treated vs. untreated) controlling for initial scores. Hypothesis 1b: IGCIP gain in spectral
and/or temporal resolution will significantly predict gain in speech recognition. This
hypothesis will be tested via regression analyses of change in speech recognition scores on
change in resolution, controlling for baseline values and also controlling for baseline
levels of speech recognition and working memory.

Aim 2: PA and reading. The investigators will explore the complex relationships amongst
auditory function, speech recognition, PA, and reading ability. Hypothesis 2a: Differential
growth in spectral/temporal resolution and/or speech recognition will predict growth in PA,
which in turn will predict mediated growth in reading. Hypothesis 2b: Growth in PA will be
associated with amount of IGCIP benefit (gain) and will mediate growth in reading, which will
be tested via cross-legged panel and path analyses. Note that testing these hypotheses is not
dependent on the outcomes of Aim 1 as only variable gain in the Aim 1 measures (e.g., speech
recognition) are required for aim 2 analyses, not a significant between-group difference for
IGCIP in Aim 1.

Aim 3: Speech and language. The investigators will compare pre- and post-IGCIP receptive and
expressive language abilities and speech production of pediatric CI recipients to the
waitlist control group. The investigators will test these skills at various time points on
standardized and clinical measures of 1) receptive language, 2) expressive language, and 3)
speech production (articulation and acoustic analyses). Hypothesis 3a: There will be
significant differences between groups for positive growth in speech and language and this
growth will be predicted by the relative improvement in auditory function (aim 1) from IGCIP
while controlling for baseline levels of working memory. Hypothesis 3b: Spectral/temporal
resolution and speech recognition and/or PA will serve as mediators of expressive and
receptive language gains and speech production gains both within and between groups. 3a and
3b will also be tested using mixed effects modeling and regression analyses to examine these
"downstream" effects. Even if no between group differences in Aim 1 and/or Aim 2 are seen,
the investigators will nonetheless be able to test whether spectral/temporal resolution,
speech recognition, and/or PA predict growth in receptive and/or expressive language and/or
changes in speech production (including subclinical acoustic analyses).

Inclusion Criteria:

1. Children aged 6 to 12 years of age

2. Prelingual onset of deafness

3. At least one CI and bilateral moderate to profound sensorineural hearing loss

- for children with a single CI, audiometric thresholds in the non-CI ear must be
consistent with at least a moderate to profound sensorineural hearing loss

4. Cochlear implantation prior to 3 years of age

5. Nonverbal cognitive abilities within the typical range

6. No confounding diagnosis such as autism spectrum disorder, neurological disorder, or
general cognitive impairment

7. Pre-operative CT scan of head performed as standard of care CI work-up

8. Post-operative CT scan--obtained either before enrollment (per VUMC CI program
standard of care) or after informed consent

Exclusion Criteria:

1. Severe anatomical abnormality(s) of the temporal bone.

2. Onset of moderate-to-profound sensorineural hearing loss after 2 years of age

3. Nonverbal intelligence standard score < 85