Effect of aspiration noise and spectral slope on perceived breathiness in vowels

Abstract

Breathy voice quality is frequently encountered in both normal and dysphonic voices. Breathiness has been associated with an increase in the intensity of aspiration noise as well as changes in spectral slope [Childers and Ahn, 1995; Fischer-Jorgenson, 1967; Huffman, 1987; Klatt and Klatt, 1990]. Shrivastav and Sapienza (2003) found that subjective ratings of breathiness obtained from a group of listeners were highly correlated with certain measures calculated from the auditory spectrum of the vocal acoustic signal. One of these measures, the partial loudness of the harmonic energy, was related to both the aspiration noise and the spectral slope of the voices. In the present experiment, 10 young adult listeners with normal hearing were presented with voices that varied systematically in terms of their aspiration noise and spectral slope. The stimuli, five male and five female voices, were generated using the Klatt synthesizer and were modeled after naturally occurring voices. Listeners rated breathiness for each of these stimuli using a 7-point rating scale. Results show the relative contribution of spectral slope and aspiration noise to the perception of breathiness.