Acoustic features of the vocalisations of two children pre- and post-cochlear implantation : the effects of auditory feedback.
Degree GrantorUniversity of Canterbury
Degree NameMaster of Audiology
The present study investigates acoustic changes to the voices of two congenitally deaf toddlers before, during, and after activation of cochlear implants (CIs). Vocal segment duration, fundamental frequency (f0), and noise index (NI) were measured from weekly recordings spanning the months immediately preceding and following implant activation. Contrary to expectations, vocal duration and f0 increased for both children in the post-activation period; NI increased for one child and decreased for the other. These findings illustrate how the restoration of auditory feedback can affect the voices of preverbal deaf infants in ways largely unobserved in older children and adult implantees. This may be due to the commencement of a developmental stage of pre-babble vocal exploration. Nevertheless, these observable effects highlight the significant role auditory feedback plays in speech development.