fricatives, fricative development, phonetic development, sex differences, speech production, spectral moments


This investigation is a comprehensive acoustic study of 4 voiceless fricatives (/f θ s ʃ/) in English produced by adults and pre-and postpubescent children aged 6-14 years. Vowel duration, amplitude, and several different spectral measures (including spectral tilt and spectral moments) were examined. Of specific interest was the pattern of normal development of the acoustic properties of fricatives and the nature of sex-specific patterns of fricative articulation in prepubescent children. Little evidence of amplitude or duration differences was found between speakers that was related to the sex of the speaker. However, significant sex-specific differences in fricative articulation were found in all groups of speakers--even in the youngest children (ages 6-7 years)--although there was an indication that some of the acoustic differences between females and males is reduced or absent in the youngest children. Results from discriminant analysis demonstrated that a discriminant function based on the adult male tokens was generally better at classifying fricatives produced by male speakers than female speakers, regardless of age. This showed that sex-related differences (presumably a function of sex-linked vocal tract variation) were present even in the youngest speaker group. However, the classification accuracy of the female model showed a steady improvement with the increased age of the female speakers and may provide support for the claim that sex-related developmental differences may just be emerging the youngest age group.

Original Publication Citation

Fox, R. A., & Nissen, S. L. (25). Sex-Related Acoustic Changes in Voiceless English Fricatives. Journal of Speech, Language, and Hearing Research, 48, 753-765.

Document Type

Peer-Reviewed Article

Publication Date


Permanent URL


American Speech-Language-Hearing Association




David O. McKay School of Education


Communication Disorders