Perception of periodically interrupted Mandarin speech

Abstract

This study investigated the effects of three interruption parameters (i.e., interruption rate, duty cycle of speech, and noise type) on the perception of Mandarin sentences. Twenty young native Mandarin listeners from Mainland China with normal hearing were instructed to identify sentences temporally interrupted by square wave. The stimuli were presented at a comfortable listening level at around 65 dB SPL and a total of 24 testing conditions with different combinations of the parameters were examined. The testing conditions included four interruption rates (i.e., rate 1, 2, 4 and 8), two duty cycles of speech (i.e., speech proportion of 50% and 33%), and three noise types (i.e., clean speech, speech-shaped noise, and 2-talker babble noise). Results showed that, overall, there was a significant main effect for duty cycle of speech on Mandarin sentence perception ability. Significant effects of the interruption rates and noise types were also found, and the sentence recognition performance was generally found to be the best in less interrupted situation, and the worst under interrupted condition masked with 2-talker babble noise. Significant interactions were also observed between duty cycle of speech and interruption rate, between interruption rate and noise type, and between duty cycle of speech and noise type. This suggested that the three parameters influenced each other. Implications of the findings of the current study for the perceptual difference of interrupted speech understanding across Mandarin and English were also discussed by considering the phonetic characteristics of the two languages. The tonal characteristics and the simpler syllable structure of Mandarin might facilitate spectro-temporal integration of the target words, contributing to a sentence intelligibility advantage of Mandarin over English under certain interrupted conditions.