Acoustic cues underlying the adjustment to talker sex in perception of fricative consonants

Abstract

Sibilant fricatives are perceived mainly by spectral peak frequency, but are also influenced by surrounding context, which includes the vowel following the fricative. The vowel contains formant structure, formant transitions out of the consonant, and information about talker sex. These factors affect fricative categorization, even if fricative energy remains unchanged. For example, frequency components in voices are lower for men than for women, and the perceived boundary between relatively high (“s”) and low (“sh”) fricatives is accordingly shifted down for men. In this study, we examined various acoustic cues that underlie accommodation to talker sex, including fundamental frequency (F0), vocal tract length (formant spacing), and breathiness/spectral tilt as they affect fricative perception. Stimuli included a fricative continuum between “s” and “sh” and a variety of vocalic contexts spoken by women and men that were controlled to vary by the aforementioned cues. Listeners identified fricatives in “s”- or “sh”-onset words, and responses were analyzed using binomial logistic regression to measure the effect of contextual cues. Results demonstrate that despite the strength of F0 as a cue for talker sex, formant spacing and spectral tilt contribute most to the context effect, consistent with the importance of spectral contrast in speech perception.