Effects of auditory feedback on fricatives produced by cochlear-implanted adults and children: acoustic and perceptual evidence.
Acoustic analyses and perception experiments were conducted to determine the effects of brief deprivation of auditory feedback on fricatives produced by cochlear implant users. The words /si/ and /Si/ were recorded by four children and four adults with their cochlear implant speech processor turned on or off. In the processor-off condition, word durations increased significantly for a majority of talkers. These increases were greater for children compared to adults, suggesting that children may rely on auditory feedback to a greater extent than adults. Significant differences in spectral measures of /S/ were found between processor-on and processor-off conditions for two of the four children and for one of the four adults. These talkers also demonstrated a larger /s/-/S/ contrast in centroid values compared to the other talkers within their respective groups. This finding may indicate that talkers who produce fine spectral distinctions are able to perceive these distinctions through their implants and to use this feedback to fine tune their speech. Two listening experiments provided evidence that some of the acoustic changes were perceptible to normal-hearing listeners. Taken together, these experiments indicate that for certain cochlear-implant users the brief absence of auditory feedback may lead to perceptible modifications in fricative consonants.
School of Behavioral and Brain Sciences, University of Texas at Dallas, Callier Center for Communication Disorders, 811 Synergy Park Blvd. Richardson, Texas 75080, USA.
Sneha V
SV
Bharadwaj
Emily A
EA
Tobey
Peter F
PF
Assmann
William F
WF
Katz
D000328:Adult; D000704:Analysis of Variance; D001307:Auditory Perception; D002648:Child; D003054:Cochlear Implants; D017626:Cochlear Nucleus / Q000503:physiopathology*; D003638:Deafness / Q000503:physiopathology* / Q000534:rehabilitation; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010700:Phonetics