Noncategorical perception of stop consonants differing in VOT

Abstract

The discriminability of bilabial stop consonants differing in VOT (the Abramson-Lisker bilabial series) was measured in a same-different task, an oddity task, and a dual response, discrimination--identification task. Subjects showed excellent within-category discrimination in all three tasks after a moderate amount of training in a same-different task with a fixed standard and with feedback. In addition, discrimination performance continuously improved with increasing stimulus difference for both intra- and intercategory comparisons. Also, subjects were able to alter their identification responses so that well-defined category boundaries fell at arbitrary values determined by the experiments. These results are not compatible with a strict interpretation of the categorical perception of stop consonants.

A unified account of categorical effects in phonetic perception

“…Stop consonants have largely been found to be identified by static temporal cues like VOT for the voicing distinction (Carney et al, 1977) and dynamic spectral cues such as rapid changes in spectra at release (Stevens and Blumstein 1978), time-varying spectral features (Kewley-Port, 1983), locus equations (Sussman et al 1991), and changes in moments (Forrest et al, 1988). Vowels, at least when they are isolated without surrounding consonants, can be largely identified by the first and second formants, representing the steady state peaks of resonant energy with certain bandwidths, a static spectral cue.…”

The motor theory of speech perception revised

“…Such availability is not always apparent because the'casual (or forgetful) listener is assumed to rely on the categorical labels, which persist in memory, rather than on the context-sensitive auditory impressions, which do not; but training or the use of more sensitive psychophysical methods is said to give better access to the auditory stage and thus to the stimulus variations-including, presumably, the differences in formant transition-that the labels ignore (Carney, Widin, & Viemeister, 1977;Pisoni & Tash, 1974;Samuel, 1977).…”

Individual differences in the acquisition of second language phonology

“…Training was discontinued either once a participant achieved criterion on this last contrast, or once they had completed a maximum of 200 trials (10 blocks), and lasted twenty to thirty minutes per stimulus type. This is a short training session compared to the amount of training that is typically administered in other phonetic training studies, where it ranges from 1 to 18 training sessions lasting up to an hour each (Carney, Widin, & Viemeister, 1977;Golestani & Zatorre, 2004;Pisoni, Aslin, Perey, & Hennessy, 1982;Strange & Dittmann, 1984).…”