Fundamental frequency development in typically developing infants and infants with severe-to-profound hearing loss.

Little research has been conducted on the development of suprasegmental characteristics of vocalizations in typically developing infants (TDI) and the role of audition in the development of these characteristics. The purpose of the present study was to examine the longitudinal development of fundamental frequency (F(0)) in eight TDI and eight infants with severe-to-profound hearing loss matched for level of vocal development. Results revealed no significant changes in F(0) with advances in pre-language vocal development for TDI. Infants with hearing loss, however, showed a statistically reliable higher variability of F(0) than TDI, when age was accounted for as a covariate. The results suggest development of F(0) may be strongly influenced by audition.