Acoustic properties contributing to the classification of place of articulation for stops.

Abstract

The production of stop consonants generates several kinds of acoustic properties: (i) the spectrum of the initial transient and burst indicating the size of the cavity anterior to the constriction; (ii) place-dependent articulatory dynamics leading to different time courses of the noise burst, onset of glottal vibrations and formant transitions; (iii) formant transitions indicating the changing vocal tract shape from the closed position of the stop to a more open configuration of the following vowel. The interest in this study is to measure the relative contributions of these acoustic properties to the classification of the consonantal place of articulation using a semi-automatic procedure. The acoustic data consisted of a number of repetitions of voiceless unaspirated stops in meaningful words spoken by several female and male speakers. The spectra averaged over the stop release and at the vowel onset were used as the acoustic feature. Speaker-independent and vowel-independent classification was about 80% using either the burst or vowel onset spectrum and a combined strategy led to a higher accuracy. Studies with additional acoustic properties that relate to articulatory dynamics, such as VOT and formant transitions, are planned.