Abstract
As the degree of judged hoarseness increases, the noise component of the spectrogram increases and replaces the harmonic structure. The relationship between these two components has been quantified as harmonics-to-noise (H/N) ratio. In this study, the contribution of cycle-to-cycle pitch perturbations (jitter) to the measured noise energy was analyzed. Moreover, the relationship between the acoustic parameters (H/N ratio and jitter) and the perceived abnormalities of hoarseness was studied. Eight laryngologists rated their auditory impressions for G, R and B factors of87pathologic voices. G (Grade) represents the degree of hoarseness; R (Rough) refers to rumbling and heaviness; B (Breathy) is related to air leakage during phonation. Correlations of R factor with the H/N ratio or jitter were not so high as those of G or B factor with the H/N ratio (p<0.05). These findings suggest that the H/N ratio can be a quantitative index of B factor as well as of G factor, and that neither of the acoustic parameters are good indicators of R factor.
