Abstract:
Research on context effects in speech-rate normalization generally focuses on the perception of phonetic categories distinguished by temporally defined cues like VOT or F2 transition duration. For example, a syllable that is heard as [ba] in the context of a slowly spoken carrier sentence will likely be identified as [wa] in a quickly spoken context [Minifie et al., J. Acoust. Soc. Am. Suppl. 1 62, S79 (1977)]. This suggests that the category boundary between [b] and [w], when based on an F2 transition duration cue, is interpreted relative to the talker's current speaking rate. One implication of prior research is that speaking rate changes only affect the perception of durational cues. However, research on phonetic cue trading suggests that temporal and spectral cues are perceived together in an integrated fashion based on phonetic knowledge. Since changes in speaking rate may restructure spectral as well as temporal cues in production, listeners may show similar context effects for perception of these cues. This study examines the effect of changing speaking rate context on the perception of [b] and [w] stimuli distinguished by variation in transition duration and extent of frequency change. Implications for theories of speech-rate normalization are discussed.