Vocal intensity in speakers and singers.

Abstract

Vocal intensity is studied as a function of fundamental frequency and lung pressure. A combination analytical–empirical model is used to predict sound-pressure levels from five professional tensors and twenty-five normal control subjects. The empirical model describes features of the glottal flow waveform (peak flow, peak flow derivative, open quotient, and speed quotient) in terms of lung pressure and phonationthresholdpressure, a key variable that incorporates the F0 dependence of many of the features of the glottal flow. The analytical model describes the contributions to SPL by the vocal tract. Results show that SPL increases with F0 at a rate of 8–9 dB per octave provided that lung pressure is raised proportional to phonation threshold pressure. SPL also increases at a rate of 8–9 dB per doubling of excesspressureoverthreshold, a new quantity that appears to assume prominence in vocal intensity calculations. For the same excess pressure over threshold, the professional tensors studied produced 10–12 dB greater intensity than the male nonsingers, primarily because their peak airflow was much higher for the same pressures.