Intelligibility and preferred rate of Chinese speaking

Abstract

This research was conducted to investigate the relationship between the rate of natural speech and intelligibility, and to examine the effects that some subject and task factors may have on Chinese speech perception. Other than the objective measure of speech intelligibility, subjective preferences of listeners towards speech rate and presentation mode were also investigated. Sixty subjects performed a set of intelligibility tests and subjective preference evaluations. The results indicated that at the rate of 4.3 characters per second (231 ms per character) previously established for professional newscasters, subjects perceived information with correctness of up to 99% and a maximum preference level was observed. Speech rates and presentation modes that were preferred by the subjects were also more easily intelligible. There was a binaural advantage over the monaural mode of presentation in speech intelligibility, and subjects generally preferred the binaural presentation to the monaural presentation. An accurate prediction of speech intelligibility was possible based on age of listener, presentation mode, and speech rate. The older subjects perceived speech less accurately and preferred slower speech than the younger subjects. The study demonstrated the importance of considering subject and task factors for compilation of standard speaking time for practical applications. Relevance to industry The results of this study are useful in generating a category of basic Chinese speaking times for standardizing speech performance and prediction of speech intelligibility and preference ratings of listeners under different listening conditions. In the reverse, the speaking rate for a certain intelligibility level can be estimated for practical use if detailed listening conditions are known.