Abstract
Purpose The purpose of the study was to examine the aging effect on the categorical perception of Mandarin Chinese Tone 2 (rising F0 pitch contour) and Tone 3 (falling-then-rising F0 pitch contour) as well as on the thresholds of pitch contour discrimination. Method Three experiments of Mandarin tone perception were conducted for younger and older listeners with Mandarin Chinese as the native language. The first 2 experiments were in the categorical perception paradigm: tone identification and tone discrimination for a series of stimuli, the F0 contour of which systematically varied from Tone 2 to Tone 3. In the third experiment, the just-noticeable differences of pitch contour discrimination were measured for both groups. Results In the measures of categorical perception, older listeners showed significantly shallower slopes in the tone identification function and significantly smaller peakedness in the tone discrimination function compared with younger listeners. Moreover, the thresholds of pitch contour discrimination were significantly higher for older listeners than for younger listeners. Conclusion These results suggest that aging reduced the categoricality of Mandarin tone perception and worsened the psychoacoustic capacity to discriminate pitch contour changes, thereby possibly leading to older listeners' difficulty in identifying Tones 2 and 3.