The effect of duration on categorical perception of Mandarin tones and aspiration of stops

Whether duration influences the categorical perception (CP) of speech is still a controversial issue. Investigations on the effect of duration of stimuli on the CP has led to opposing results. The present study focused on the effect of duration on the CP of Mandarin lexical tones and aspiration of stops, in which the speech rates were normal for speech production and perception. The results showed that there was no significant duration effect on the CP of lexical tones. However, we found that syllable duration significantly changed the voice onset time (VOT) values of boundary position of aspiration of stops, although the discrimination ability of aspiration was not influenced by syllable duration, indicating that people have a robust perceptual competence to systematically encode alterations of speech production.