The MFCC Vowel Space of [ɤ] in Grammatical and Lexical Word in Standard Chinese

This study investigated the phonetic quality of [ɤ] in the light syllables of grammatical words and the non-light syllables of content words. By using the Mandarin Speech Test Materials as the main linguistic materials, audio data of 10 native speakers of Standard Chinese was collected for this study. After the audio data collection, the Mel Frequency Cepstral Coefficents of [ɤ] in both conditions were extracted as the acoustic feature. Then, the dimension of MFCCs was reduced through Laplacian eigenmaps in order to construct the 3D acoustic space. Also, an independent T-test was applied to test the differences of the three-principal-dimension data be-tween the light and non-light [ɤ]. The results of 3D vowel space and independent T-test jointly show that the quality of [ɤ] in light syllables distinguish from that in non-light syllables. Therefore, results of the present study may suggest that the traditional term light-tone is not an accurate term for describing the phenomenon of light syllable in Mandarin. Furthermore, considering any possible variations of vowel quality under different lexical context may improve the output of natural speech processing of Standard Chinese.