Spectrographic comparison of two types of spastic dysphonia.

A spectrographic comparison of the voices of two patients with spastic dysphonia demonstrated differences in vocal characteristics. The voice of one patient was characterized by intermittent breathiness which appeared spectrographically as a breakdown in formant structure or as the addition of fricative fill superimposed upon resonance bars. The voice of the second patient was characterized by strain-strangle phonation which appeared spectrographically as widely and irregularly spaced vertical striations. The contrasting vocal characteristics of the two patients are compatible with the viewpoint that there may be two types of spastic dysphonia.