Selective adaptation for acoustic cues of voicing in initial stops

Abstract

Recent experiments have indicated that perceptual adaptation effects can be obtained for a series of CV syllables (e.g. [ba–[pha]) varying along the acoustic dimension of Voice Onset Time (VOT), defined as the interval between the onset of the consonant release burst and the onset of voicing. These adaptation effects have led researchers to postulate the existence of a small set of linguistic feature detectors, each sensitive to a restricted range of Voice Onset Time values. However, another acoustic cue for voice-voiceless distinctions among the initial stop consonants, namely the presence or absence of significant formant transitions following the onset of voicing, covaried with absolute VOT in each of the previous adaptation experiments. In this study, differential adaptation effects are obtained along a VOT test dimension by presenting adapting stimuli which contain different amounts of formant transitions after voicing onset but which contain the same absolute VOT. The results indicate that the original adaptation effects are partly attributable to the presence or absence of the formant transitions after voicing onset, rather than to VOT per se. The present results may be attributable to adaptation of a detector sensitive to a weighted combination of the two hypothetical cues of VOT and the duration of voiced transitions.