Although the spectrally degraded input provided by cochlear implants (CIs) is sufficient for speech perception in quiet, it poses problems for talker identification. The present study examined the ability of normally hearing (NH) children and child CI users to recognize cartoon voices while listening to spectrally degraded speech.
In Experiment 1, 5- to 6-year-old NH children were required to identify familiar cartoon characters in a three-alternative, forced-choice task without feedback. Children heard sentence-length utterances at six levels of spectral degradation (noise-vocoded utterances with 4, 8, 12, 16, and 24 frequency bands and the original or unprocessed stimuli). In Experiment 2, child CI users 4 to 7 years of age and a control sample of 4- to 5-year-old NH children were required to identify the unprocessed stimuli from Experiment 1.
NH children in Experiment 1 identified the voices significantly above chance levels, and they performed more accurately with increasing spectral information. Practice with stimuli that had greater spectral information facilitated performance on subsequent stimuli with lesser spectral information. In Experiment 2, child CI users successfully recognized the cartoon voices with slightly lower accuracy (0.90 proportion correct) than NH peers who listened to unprocessed utterances (0.97 proportion correct).
The findings indicate that both NH children and child CI users can identify cartoon voices under conditions of severe spectral degradation. In such circumstances, children may rely on talker-specific phonetic detail to distinguish one talker from another.
This paper examines the ability of children with normal hearing (NH) and children with cochlear implants (CIs) to identify familiar cartoon voices in a forced-choice task. In Experiment 1, NH children identified familiar cartoon characters from unprocessed utterances as well as from vocoded utterances with 4-24 frequency bands. Performance was above chance levels, but increasing spectral detail enhanced accuracy. In Experiment 2, young deaf children with bilateral CIs identified the same cartoon characters from unprocessed utterances. These findings indicate that NH children and child CI users have representations of cartoon voices that support talker recognition under conditions of spectral degradation.
1Laboratoire de Sciences Cognitives et Psycholinguistique, CNRS/EHESS/DEC-ENS, Paris, France; and 2Department of Psychology, University of Toronto, Mississauga, ON, Canada.
This work was supported by grants from the Natural Sciences and Engineering Research Council of Canada (to S.E.T. and E.G.S.).
The authors declare no conflict of interest.
Address for correspondence: Sandra E. Trehub, Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON, Canada L5L 1C6. E-mail: email@example.com