Towards standard scales for dysphonic voice quality: Magnitude estimation of reference stimuli

Abstract

This work represents a critical step in developing standard measurement scales for the dysphonic voice qualities of breathiness and roughness. Methods such as Likert ratings, visual analog scales and magnitude estimation result in arbitrary units, limiting their clinical usefulness. A single-variable matching task can quantifying voice quality in terms of physical units but is too time consuming for clinical use. None of these methods result in information that has a direct or intuitive relationship with the underlying percept. A proven approach for the perception of loudness is the Sone scale which ties physical units to the perceptual estimates of loudness magnitude. As a first step in developing such a scale for breathiness and roughness, here we establish the relationship between the change in perceived VQ magnitude and the change in physical units along the continuum of each VQ dimension. A group of 25 listeners engaged in a magnitude estimation task to determine perceived magnitude associated with the comparison stimuli used in our single-variable matching tasks. This relationship is analogous to mapping intensity in dB to perceived loudness in Phons and is a critical step in developing a Sone-like scale for breathiness and roughness.