Voice register in Suai (Kuai): an analysis of perceptual and acoustic data

Analyses of the perceptual and acoustic characteristics of the Register 1 ('clear') versus Register 2 ('breathy') distinction have been carried out on the Kuai dialect of Suai, a Mon-Khmer language. The perception results were obtained from five-parameter synthesized stimuli. They showed that the primary parameter underlying the distinction is the frequency of onset of laryngeal excitation (F0). One other parameter making a significant contribution was the open quotient. The F0 result was confirmed by an acoustic analysis of eight pairs of natural utterances produced by native speakers. We conclude that the Suai language is in a state of flux with respect to the voice registers, although the distinction has not disappeared. The perceptual data reveal mixed levels of sensitivity, and the production data indicate that some speakers maintain a fairly good distinction, while others do not. The language seems to be replacing the register distinction with a prosodic one of pitch accent, possibly as a stage leading to tonogenesis.