Some Acoustic Observations on the Distinction of Place of Articulation for Voiceless Nasals in Burmese

Abstract

Burmese has voiced-voiceless contrast of nasal sounds. The opposition between voiced and voiceless nasals stands in parallel with the one between aspirated and unaspirated consonants in regard to some grammatical function. The verb with a voiceless nasal initial is the "transitive, " "active" or "causative" correlate of the verb with an ordinary voiced nasal initial. The present study describes the acoustic nature of voiceless nasals in Burmese based on the analysis of waveforms by a minicomputer using a linear prediction algorithm (LPC), and the discrimination of place of articulation by statistical study. Voiceless nasals consist of voiceless nasal friction portions and voiced nasal murmur portions. The intensity of the former is extremely weak and we could not find a significant difference according to the point of articulation. Therefore, we analyzed the voiced murmur portion of voiceless nasals and tried to find significant cues which can distinguish the point of articulation. As a result, we have been able to distinguish bilabial nasals, alveolar nasals and velar nasals by means of step-wise discriminant analysis of the values of nasal formant frequencies N1, N2 and N3, and bandwidths B1, B2 and B3. These results support the interpretation that voiced murmur portions of voiceless nasals in Burmese include significant cues which can distinguish points of articulation.