Acoustic study of throaty voice quality

“Throaty” voice quality has been regarded by voice pedagogues as undesired and even harmful. The present study attempts to identify acoustic and physiological correlates of this quality. One male and one female subject read a text habitually and with a throaty voice quality. Oral pressure during p-occlusion was measured as an estimate of subglottic pressure. Long-term-average spectrum (LTAS) analysis was used to describe the average voice quality. Sixteen syllables, perceptually evaluated with regard to throaty quality by five experts, were selected for further analyses. Formant frequencies and voice source characteristics were measured by means of inverse filtering, and the vocal tract shape of the male subject’s throaty and normal versions of the vowels [a,u,i,ae] was recorded by Magnetic Resonance imaging. From this material area functions were derived and their resonance frequencies were determined. To test the relevance of formant frequencies to perceived throaty quality, experts rated degree of throatiness in synthetic vowel samples in which the subjects’ measured formant frequency values were used. The main acoustic correlates of throatiness seemed to be an increase of F1, a decrease of F4 and in front vowels also a decrease of F2, presumably resulting from a narrowing of the pharynx. In the male subject voice source parameters suggested a more hyperfunctional voice in throaty samples.