A model for the prediction of breathiness in vowels

Abstract

The perception of breathiness in vowels is cued by multiple acoustic cues, including changes in aspiration noise (AH) and the open quotient (OQ) [Klatt and Klatt, J. Acoust. Soc. Am. 87(2), 820-857 (1990)]. A loudness model can be used to determine the extent to which AH masks the harmonic components in voice. The resulting "partial loudness" (PL) and loudness of AH ["noise loudness" (NL)] have been shown to be good predictors of perceived breathiness [Shrivastav and Sapienza, J. Acoust. Soc. Am. 114(1), 2217-2224 (2003)]. The levels of AH and OQ were systematically manipulated for ten synthetic vowels. Perceptual judgments of breathiness were obtained and regression functions to predict breathiness from the ratio of NL to PL (g) were derived. Results show that breathiness can be modeled as a power function of g. The power parameter of this function appears to be affected by the fundamental frequency of the vowel. A second experiment was conducted to determine if the resulting power function could estimate breathiness in a different set of voices. The breathiness of these stimuli, both natural and synthetic, was determined in a listening test. The model estimates of breathiness were highly correlated with perceptual data but the absolute predicted values showed some discrepancies.

Voice attractiveness: Influence of stimulus duration and type

“…Finally, betweenrater agreement for attractiveness ratings was high and did not differ according to stimulus type, suggesting a good reliability of participants' judgments for vowels as well as for words. Consequently, all stimulus types investigated can be confidently used, and the choice of a given stimulus type (when several are available, as in our GEAD) should depend on whether priority is given to acoustics measurements (then vowels are good candidates; e.g., Patel et al, 2011;Shrivastav, Camacho, Patel, & Eddins, 2011) or to prosody and content (then a word such as "bonjour" may be more appropriate). This experiment provides elements to answer methodological questions that many researchers in voice attractiveness might have raised at some point when designing their experiments.…”

Pitch strength of normal and dysphonic voices

“…The present study was designed to explore the potential relationship between pitch strength and voice quality and was motivated by prior research to understand the perception of breathiness in vowels (Shrivastav and Sapienza, 2003;Cummings et al, 2008;Shrivastav et al, 2007;Shrivastav et al, 2011). The current results demonstrate that listeners are capable of scaling the pitch strength of voices that vary in voice quality and that pitch strength judgments vary systematically with variations in voice quality.…”

“…Recent work has attempted to predict judgments of vocal breathiness using computational models that incorporate aspects of auditory processing (e.g., Shrivastav, 2003;Shrivastav and Sapienza, 2003;Shrivastav and Camacho, 2010;Shrivastav et al, 2011). If the output of a computational model can accurately predict perceptual judgments, then the likelihood of both understanding the relevant perceptual processes and development of objective voice quality metrics will be increased.…”

“…The NL and PL measures computed from the loudness model are correlated with perceptual judgments of breathiness. Specifically, perceived breathiness is inversely related to PL and proportional to NL (Shrivastav, 2003;Shrivastav and Sapienza, 2003;Shrivastav and Camacho, 2010;Shrivastav et al, 2011). The ratio of noise loudness to partial loudness (referred to as "g") was used as the primary predictor of perceived breathiness.…”

“…If the output of a computational model can accurately predict perceptual judgments, then the likelihood of both understanding the relevant perceptual processes and development of objective voice quality metrics will be increased. The models of Shrivastav et al (2011) have been based on the assumption that voiced speech stimuli have both periodic (harmonic) and aperiodic (noise) elements. Accordingly, they used variants of the partial loudness model of Moore et al (1997) where the partial loudness (PL) is associated with the harmonic energy of the vowel that is masked by the aperiodic components of the same voice.…”