The Phonation Factor in the Categorical Perception of Mandarin Tones

This study presents a new way of observing the categorical nature of Mandarin tone perception by considering the phonation factors in the experiment design. In order to demonstrate the reliability of experiment materials, a pitch synchronous overlap-add (PSOLA) method is used to produce the speech stimuli, and an inversefiltering method is applied to assess the invariability of sound source of the stimuli. Results provide evidence for the prediction that phonation factors are adopted in perceiving tones by Mandarin speakers. Especially for the tone which has a special voice characteristic, such as the third tone in Mandarin, the perception difference among continua with different voice qualities is much more obvious. Results also suggest that there is categorical perception for each pair of two tones in Mandarin. These results lead to a discussion about the necessity of a wider and more integrated theory model for describing tones in tone languages, in which the phonation factors should be considered.