Evaluating a model to estimate breathiness in vowels

Abstract

The perception of breathiness in vowels is cued by 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), 2218–2224 (2005)]. 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 NL/PL were derived. Results show breathiness to be a power function of NL/PL when NL/PL is above a certain threshold. This threshold appears to be affected by the stimulus pitch. A second experiment was conducted to determine if the resulting power function could be used to estimate breathiness in natural voices. The breathiness of novel stimuli, both natural and synthetic, was determined in a listening test. For comparison, breathiness for the same stimuli was also estimated using the power function obtained previously. Results show the extent to which findings can be generalized. [Research supported by NIH/R21DC006690.]