ISCA Archive Interspeech 2015
ISCA Archive Interspeech 2015

Investigating consonant reduction in Mandarin Chinese with improved forced alignment

Jiahong Yuan, Mark Liberman

Phonetic reduction has been an important topic in linguistics research. It also presents a great challenge for forced alignment, a technique widely used for automatic phonetic segmentation. In this study, we employed skip-state HMMs to improve forced alignment quality and to make forced alignment applicable to the investigation of phonetic reduction and deletion. With skip-state HMMs, forced alignment accuracy at 10 ms agreement was improved from 73.3% to 75.6% on a corpus of Mandarin Chinese broadcast news speech. Our analysis based on the improved forced alignment of Mandarin broadcast news speech — verified by hand segmentation of a random sample of cases — shows that: 1. The durations of frication and aspiration are additive in the production of plosives and affricates; 2. Plosives are more likely to be deleted than affricates; and 3. Plosives and affricates in higher-frequency words and at word-medial position are more likely to be reduced.