Gender-specific vocal dysfunctions in Parkinson's disease: electroglottographic and acoustic analyses

Electroglottographic (EGG) and acoustic recordings were obtained during sustained vowel production in men and women suffering from Parkinson's disease (PD). The computed EGG spectrograms allowed us to differentiate various kinds of phonatory disturbances: intervals with subharmonic energy ("low-frequency segments"), "noise-like regions," and abrupt shifts of fundamental frequency (F0). Female PD subjects presented with a significantly increased portion of subharmonic segments and with significantly more abrupt F0 shifts as compared to both controls and male PD subjects. Presumably, these alterations in spectral energy distribution reflect different oscillatory modes of the glottal source. Thus, PD seems to have a differential impact on phonation in men and women. Conceivably, these gender-specific vocal dysfunctions are determined by the well-known sexual dimorphism of laryngeal size.