Some parameters affecting the perception of voicing for fricatives

Measurements of voicing have shown that low-frequency periodicity can usually be found at VC and CV boundaries, specifically in the initial 30 ms or the final 20 ms of a phonetically “voiced” fricative. The purpose of this study is to determine the perceptual importance of voicing at VC and CV boundaries for fricatives. The VCV tokens with alveolar fricatives were synthesized with various fricative durations and various patterns of voicing within the consonant. Listeners identified the consonant as either [s] or [z]. Short fricatives are heard as [z] but, for durations longer than 70 ms, voicing must occur at either the VC or CV boundary. Voicing placed in the middle of the fricative did not elicit [z] responses. When voicing occurred at the boundaries, perception was influenced by fricative duration, and by amplitude and duration of voicing. Possible theoretical interpretations of the data will be discussed. [Work supported by grants from NINCDS to Brown University and to MIT.]