Tone discrimination in Mandarin Chinese

Intelligibility testing for Mandarin Chinese speech has, to date, consisted of an evaluative methodology derived by translating the methods of the English language ANSI standard S3.2 diagnostic rhyme test and modified rhyme tests into Chinese. Language-specific tests for Chinese are important not only due to the rapidly increasing prevalence of Chinese speech conveyed by the world telecommunications system, but also due to several features of Chinese that differ markedly from English and many other European languages, and which are thus untested by the english-language intelligibility evaluation methods. The previously published test methodologies, proposed as an international standard, have been used in the definition of speech coding systems specifically tailored to Chinese speakers, and in the evaluation of the ability of several current speech codec standards to cater for Chinese speech -and in particular Chinese lexical tones. Usage is likely to grow in future. This paper presents new experimental evidence on the discrimination of Chinese tone that overturn assumptions made in the proposed Chinese intelligibility test standard, and leads here to a new formulation of the intelligibility test relating to tone discrimination.