Feasibility of measurement of a voice range profile with a semi-occluded vocal tract.

Semi-occlusion of the vocal tract may provide a new method for assessing ranges of F(0) and a physiological correlate of vocal intensity. Signals can be obtained without concern about room noise, steadiness in mouth-to-microphone distance, and possibly without vocal injury caused by excessive loudness produced. Nine volunteers participated. Steady and acoustic pressures behind the lips were measured. Traditional voice range profiles were obtained on the vowels /α/ and /u/ for comparison. Range of F(0) was not limited in most subjects with the semi-occlusion but may be restricted in some subjects. In the lower portion of the F(0) range, the highest and lowest steady pressures at the semi-occlusion constitute an oral pressure range profile.