Interspeech'2005 - Eurospeech
This study compared the voice quality of high and low falling unchecked and checked tones. Spectral tilt measured as H0-A2 was taken from the syllable midpoint of second, third and four syllables in SVO sentences. Results showed that the voice quality of checked tones was not always creakier than unchecked tones. The voice quality of a syllable at the end of an utterance was not creakier than a syllable at the beginning of an utterance. Narrow focus was a salient factor affecting voice quality. While voice quality of narrow focus syllables became creakier, voice quality of post-focus syllables became more breathy. Focus, a prosodic factor, affected voice quality in a more consistent manner than did lexical tone and syllable position within an utterance in Taiwan Min (Taiwanese).
Bibliographic reference. Pan, Ho-hsien (2005): "Voice quality of falling tones in taiwan min", In INTERSPEECH-2005, 1401-1404.