Intelligibility of locally time-reversed speech: A multilingual comparison

Abstract

A set of experiments was performed to make a cross-language comparison of intelligibility of locally time-reversed speech, employing a total of 117 native listeners of English, German, Japanese, and Mandarin Chinese. The experiments enabled to examine whether the languages of three types of timing - stress-, syllable-, and mora-timed languages - exhibit different trends in intelligibility, depending on the duration of the segments that were temporally reversed. The results showed a strikingly similar trend across languages, especially when the time axis of segment duration was normalised with respect to the deviation of a talker's speech rate from the average in each language. This similarity is somewhat surprising given the systematic differences in vocalic proportions characterising the languages studied which had been shown in previous research and were largely replicated with the present speech material. These findings suggest that a universal temporal window shorter than 20-40 ms plays a crucial role in perceiving locally time-reversed speech by working as a buffer in which temporal reorganisation can take place with regard to lexical and semantic processing.