Perceptual Consequences of Variability in Native and Non-Native Speech

Abstract

Background/Aims: Native speakers often have a difficult time understanding non-native speech, and this challenge is frequently attributed to a more variable signal. While theories and models of general speech perception are grounded in issues of variability, they rarely consider non-native speech. Here, we ask how a specific type of variability (speaking rate) impacts two measures of perception for both native and non-native speech. Methods: In the present study, one group of listeners transcribed speech, providing a measure of intelligibility. A second group of listeners rated how fluent the speaker was, providing a measure of fluency. Results: The results show that variability in speaking rate correlates with a non-native speaker’s intelligibility. However, perceived fluency measures are not predicted by this variability measure. Conclusions: These results, taken with studies of the range of variability in non-native speech, suggest that variability in non-native speech is not a monolithic construct. Current theories and models of perception can be enhanced by examining non-native speech and how variability in that speech impacts perception.