Approximately 60,000 people worldwide have received cochlear implant devices for their hearing. Following implantation, these individuals not only gain the ability to hear others, but also to hear themselves while they speak (auditory feedback). There is increasing evidence that auditory feedback (AF) is important for speech production; however, much remains to be understood regarding the role of AF, particularly for speech development.
The specific aims of this research are to: (1) investigate properties of speech that are modified when cochlear-implanted children speak in the brief absence of AF; (2) compare effects of AF on speech produced by early-implanted (received cochlear implant before 3 years of age) versus late-implanted children (received implant after 5 years of age); and (3) determine the critical time interval between AF deprivation and concomitant changes in speech.
These aims are part of a long-range plan to better understand the influences of speech perception on speech production. Ten early- and ten late-implanted children (ages 6-12 years) will read simple phrases in speech processor-ON and -OFF conditions. The following speech properties will be measured using acoustic analysis: vowel formant frequencies, stop consonant voice onset times, fricative spectral moments, syllable-level fundamental frequencies, and word and phrase durations. Analysis of variance with planned comparisons will be used to test the following hypotheses: (1) suprasegmental and segmental properties of speech are modified in the brief absence of AF; (2) early-implanted children show larger speech changes in the absence of AF than late-implanted children; and (3) segmental properties of speech are modified when AF is eliminated for less than a second. The results will have both clinical and theoretical implications in that they: (1) will inform clinicians of the minimal time window over which speech improvements can be expected following implantation; and (2) offer unique means of testing 'internal model'-based theories of sensory feedback during speech production.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
1R03DC007052-01
Application #
6840672
Study Section
Special Emphasis Panel (ZDC1-SRB-A (40))
Program Officer
Shekim, Lana O
Project Start
2004-08-01
Project End
2007-07-31
Budget Start
2004-08-01
Budget End
2005-07-31
Support Year
1
Fiscal Year
2004
Total Cost
$74,750
Indirect Cost
Name
University of Texas-Dallas
Department
Psychology
Type
Other Domestic Higher Education
DUNS #
800188161
City
Richardson
State
TX
Country
United States
Zip Code
75080
Bharadwaj, Sneha V; Graves, Amanda G (2008) Efficacy of the discreteness of voicing category (DOVC) measure for characterizing voicing errors in children with cochlear implants: a report. J Speech Lang Hear Res 51:629-35
Bharadwaj, Sneha V; Graves, Amanda G; Bauer, Delia D et al. (2007) Effects of auditory feedback deprivation length on the vowel /epsilon/ produced by pediatric cochlear-implant users. J Acoust Soc Am 121:EL196-202