The relationship among voice onset, voice quality, and fundamental frequency: a dynamical perspective.

In dynamical motor theory, skill acquisition occurs as a modification of preexisting coordination patterns or attractor states. The purpose of this study was to assess how different levels of voice onset, voice quality, and fundamental frequency (F(0)) combine to form the attractor states common to voice motor control. Three levels of voice onset (glottal, simultaneous, and breathy), voice quality (modal speech, mixed, and falsetto), and fundamental frequency (low, mid, and high) were manipulated by vocally untrained, female subjects. Percent correct of acquisition trials and self-report of effort were used as measures of stable phonations indicative of an attractor state. Using intensity as a covariate, the results provided support for two of the three predicted triads representing attractor states in female speakers: (1) glottal onset/modal speech quality/low F(0); and (2) breathy onset/falsetto quality/high F(0). The results of this study suggest that certain parameters of voice motor control, such as onset, quality, and F(0), exist as part of a dynamical system that can be identified and manipulated in voice motor acquisition and learning.