Huang, J. & Holt, L. L. (2009). General perceptual contributions to lexical tone normalization. Journal of the Acoustical Society of America. 125(6), 3983–3994.
Presentation: Hsiao-chien
Summary: Chris
Since pitch cues are used to contrast meanings in tonal languages, listeners may encounter variability in the speech signal. It is possible that listeners rely on context to resolve this problem. This study aims to test the influence of the precursor context on contour tone perception. The second aim is to explore the mechanisms of perception. In Experiment 1, the authors adopted paradigms similar to level tone perception in previous studies and aimed to see whether the context effect can be extended to contour tones. They varied the context (high F0 vs. low F0) preceding the target tones (Tone 1 vs. Tone 2). Results showed that manipulation of F0 onset frequency was sufficient to shift Mandarin tone perception of isolated syllables. Experiment 2 utilized complex non-speech signals composed of four sine waves sharing the same F0 to test the possibility of general auditory processing. Results showed that the non-speech context with a high F0 shifted listeners’ lexical tone responses to Tone 2, suggesting that general auditory processes may play a role in speaker normalization. Experiment 3 used a simpler non-speech analog by examining the first harmonics alone. Results were almost the same as the results in Experiment 2. Therefore, the authors considered the spectral energy of the mean fundamental frequency appears to be a key characteristic predicting the influence of context on tone identification. The conclusion is that the average F0 of speech contributes to tone perception and that the effect of speech context is contrastive.
