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.