What does it mean for a voice to be “normal?”

Abstract

It is rather unclear what is meant by “normal” voice quality, just as it is unclear what is meant by “voice quality” in general. A clearer understanding of what listeners perceive as normal and what strikes them as disordered would benefit both clinical practice, for which a normal sound is presumably the goal of treatment, and the study of voice quality in general. To shed light on this matter, listeners heard 1-sec sustained vowels produced by 200 speakers (100 male and 100 female), half of whom were recorded in the clinic (ranging from mild to fairly severe pathology) and half of whom were UCLA students with no known vocal disorder. Listeners compared 20 voices at a time in a series of sort-and-rate trials, and ordered them in a line according to the severity of perceived vocal pathology. Any voices perceived as normal were placed in a box at one end of the line. Preliminary results indicate that listeners agreed fairly well about which voices were not normal, but not at all about which were normal. Implications of these findings for evaluation of voice in and out of the clinic will be discussed. [Work supported by NIH and NSF.]