The Importance of Acoustic Temporal Fine Structure Cues in Different Spectral Regions for Mandarin Sentence Recognition.

OBJECTIVES

To study the relative contribution of acoustic temporal fine structure (TFS) cues in low-, mid-, and high-frequency regions to Mandarin sentence recognition.

DESIGN

Twenty-one subjects with normal hearing were involved in a study of Mandarin sentence recognition using acoustic TFS. The acoustic TFS information was extracted from 10 3-equivalent rectangular bandwidth-wide bands within the range 80 to 8858 Hz using the Hilbert transform and was assigned to low-, mid-, and high-frequency regions. Percent-correct recognition scores were obtained with acoustic TFS information presented using one, two, or three frequency regions. The relative weights of the three frequency regions were calculated using the least-squares approach.

RESULTS

Results indicated that the mean percent-correct scores for sentence recognition using acoustic TFS were nearly perfect for stimuli with all three frequency regions together. Recognition was approximately 50 to 60% correct with only the low- or mid-frequency region but decreased to approximately 5% correct with only the high-frequency region of acoustic TFS. The mean weights of the low-, mid-, and high-frequency regions were 0.39, 0.48, and 0.13, respectively, and the difference between each pair of frequency regions was statistically significant.

CONCLUSION

The acoustic TFS cues in low- and mid-frequency regions convey greater information for Mandarin sentence recognition, whereas those in the high-frequency region have little effect.