Francis, A. L., Ciocca, V., Wong, N. K. Y., Leung, W. H. Y., & Chu, P. C. Y. (2006). Extrinsic context affects perceptual normalization of lexical tone. Journal of Acoustic Society of America, 119, 1712–1726.
Presentation: Roger
Summary: Chris
This study investigated how listeners utilized contextual cues for the normalization of pitch range in tonal identification. According to the Pitch Range Assessment Model (PRAM), listeners usually normalize speakers’ pitch range based on contexts. The wider pitch range the context has, the better listeners’ normalization performance will be. Experiment 1 tested how subjects normalized tonal range using two different types of contexts, one with a normal range of frequency variation and the other with the F0 held constant, which is equal to the average F0 of the context. Also, three kinds of degree shifts were manipulated to test the magnitude of contextual effect. Results showed that shifting contextual pitch downward led to more high-level responses while shifting the pitch range upwards elicited more low-level responses. Experiment 2 examined and compared the magnitude of contextual effects with the preceding and the following contexts. Results showed that raising the following context had a stronger effect than raising the preceding context. However, the effects of lowering the preceding and the following contexts were similar. It was suggested that the location of context should be taken into consideration in PRAM. Experiment 3 intended to answer the question whether the normalization of lexical tones was a linguistic process or merely an auditory process. The linguistic contexts were replaced with sounds generated by the hummed neutral vocal tract function in Praat. Results showed that listeners were unable to normalize lexical tones embedded in linguistically meaningless contexts. Experiment 4 examined how talker identity influenced tonal normalization. Results showed that no significant difference was found between the same talker condition and the different talker condition. In conclusion, the mechanism of estimating one’s tonal range is a process of extrapolation from the talker’s average F0. Furthermore, tonal normalization is a process involving integration of different positions (the preceding and the following contexts) and different sources of pitch perception.
This study investigated how listeners utilized contextual cues for the normalization of pitch range in tonal identification. According to the Pitch Range Assessment Model (PRAM), listeners usually normalize speakers’ pitch range based on contexts. The wider pitch range the context has, the better listeners’ normalization performance will be. Experiment 1 tested how subjects normalized tonal range using two different types of contexts, one with a normal range of frequency variation and the other with the F0 held constant, which is equal to the average F0 of the context. Also, three kinds of degree shifts were manipulated to test the magnitude of contextual effect. Results showed that shifting contextual pitch downward led to more high-level responses while shifting the pitch range upwards elicited more low-level responses. Experiment 2 examined and compared the magnitude of contextual effects with the preceding and the following contexts. Results showed that raising the following context had a stronger effect than raising the preceding context. However, the effects of lowering the preceding and the following contexts were similar. It was suggested that the location of context should be taken into consideration in PRAM. Experiment 3 intended to answer the question whether the normalization of lexical tones was a linguistic process or merely an auditory process. The linguistic contexts were replaced with sounds generated by the hummed neutral vocal tract function in Praat. Results showed that listeners were unable to normalize lexical tones embedded in linguistically meaningless contexts. Experiment 4 examined how talker identity influenced tonal normalization. Results showed that no significant difference was found between the same talker condition and the different talker condition. In conclusion, the mechanism of estimating one’s tonal range is a process of extrapolation from the talker’s average F0. Furthermore, tonal normalization is a process involving integration of different positions (the preceding and the following contexts) and different sources of pitch perception.
