Some Parameters of Vocal Effort

Abstract

Vocal effort (autophonic level) for the vowel /a/ in the modal register was measured by magnitude estimation and production as a function of the SPL developed as well as changes in fundamental frequency. Maximum, minimum, and most comfortable effort levels were determined. No standard was used. Magnitude of production was numerically assigned from data obtained from each of five male subjects. The results show that vocal effort is a power function of both SPL and fundamental frequency. As has been previously found in investigations of loudness over a wide range of values where a standard was not assigned, most of the present power functions were concave downward. It has been previously implied [Wright, “Is There A Standard Loudness?” J. Acoust. Soc. Amer. 37, 1175(A) (1965)] that the implicit standard is a most comfortable level and that this level occurs in the vicinity of the slope change in the power function. Such was the case in this investigation. The most comfortable effort level almost invariably occurred where the obtained power functions changed their slopes, both in terms of SPL and fundamental frequency.