Speech and voice physiology of children who are hard of hearing

Objective: The purpose of this investigation was to examine the nature and frequency of deviant speech and voice physiology in children who are hard of hearing (HH). Design: Ten HH children (age, 5 to 15 yrs) participated. Their hearing losses ranged in severity from moderate to severe. The following speech/voice physiological measures were examined: frequency of occurrence of negative intraoral air pressure (-P-o), magnitude of P-o, phonatory air flow, nasal air flow, voice onset time (VOT), and fundamental frequency (Fo). Findings were compared with data previously collected from 56 children with normal hearing and 7 children with cochlear implants (Higgins, McCleary, Carney, & Schulte, 2003). Results: Five of the 10 HH children exhibited deviant speech/voice behaviors. Only one showed deviancy on more than one measure. In addition, 8 HH children had some borderline-deviant speech behavior. The frequency and degree of speech/voice deviancy for the children in the present study was far less than what we previously had observed for children who underwent cochlear implantation after 5 yrs of age (Higgins et al., 2003). This was the case even for a child with a cochlear implant from our earlier study who eventually achieved speech perception scores that were as good as or better than some of the HH children in the present investigation. Conclusions: Deviant speech/voice physiology occurs to a limited extent for some HH children. Of the measures that we examined, those related to vocal fold tension and vocal fold articulation appeared to be most sensitive to the effects of diminished auditory input and feedback that occurs for HH children. Data from this and other studies suggest that abnormally high F-0 occurs for about 20% of HH children and may be associated with poor speech perception skills. Future studies should examine whether earlier implantation can help deaf children to produce speech that is at least as normal as that of HH children.