Phonation types in Suai

Abstract

Many Mon-Khmer languages have such phonologically distinctive phonation types as modal, breathy, and creaky voice. The Suai language studied here is spoken in northeastern Thailand. Literature exists on these phonation types (‘‘voice registers’’), including some attention to acoustics; however, no perceptual studies appear to have been published. Suai was chosen here because it has just two contrasting categories conventionally labeled modal voice versus breathy voice. The Klatt synthesizer was used to control five of its parameters: F0, amplitude of turbulence, open quotient of the voicing waveform, overall gain, and spectral tilt. All combinations of these parameter settings yielded 51 variants of a basic syllable. These stimuli were identified by native speakers as one word or the other of a minimal pair. The results showed breathiness and pitch to be major cues. The original recordings of our informants, however, appeared only to have a pitch difference, an impression tested by acoustic analysis. A reliable difference was found only in F0 contours, with a lower one on the ‘‘breathy’’ type. There appears to be evidence for an ongoing shift from a system of phonation types to one of tones. [Work supported by NIH Grant DC-02727 and the Thailand Research Fund.]