Acoustic correlates of pathologic voice types.

Listeners classified 49 samples of vowels /a/ and /i/ on the basis of four voice types: hoarse, breathy, strained, and normal. The vowels were analyzed acoustically for mean harmonic/noise differences in four spectral regions, average fundamental frequency, natural logarithm of fundamental frequency, and jitter. Discriminant analysis showed that classifications of voice type were made with 80% accuracy using three acoustic parameters: (a) mean harmonic/noise difference factor (1-3.5 kHz), (b) natural log of fundamental frequency, and (c) vowel type. The significance of these particular acoustic parameters for the perception and classification of voice types is discussed.