The effects of vowel quality and pitch on spectral and glottal flow measurements of the voice source

Abstract

In efforts to evaluate voice quality, the voice source is frequently assessed using measurements of the voice spectrum and/or measurements of the glottal flow. In normal dynamic speech, though, speakers not only change their voice quality, but also their vowel qualities (i.e., they say different words) and their pitch (i.e., they use different intonation contours). The purpose of this study is to explore how vowel quality and pitch affect both spectral and glottal flow measurements of source characteristics. In the experiment, speakers are asked to say several words on three pitches each. Since these are real words, speakers should produce them in their normal, but undefined, voice quality. Samples are selected from the center of each vowel. Differentiated glottal flow is obtained by inverse filtering and is then matched with an LF model. The voice spectrum is evaluated using the measurements H1-H2, H1-A1 and H1-A3 (as proposed by Stevens and Hanson 1995). These measurements are then compared across vowels, pitches and speakers. [Work supported by the French Ministry of Foreign Affairs and NIH/NIDCD.]