[The 3-dimensional voice field].

Abstract

Extension of the voice field (voice profile) by a third variable which characterizes the phonation has various advantages as well as drawbacks. Since the voice field evaluates the laryngeal function, the use of aerodynamic variables improve the representation of the laryngeal efficiency in the voice field. On the other hand, the measurement of these variables complicates the method. When voice quality measures (presence of singing formant, sharpness) are used as the third dimension, the limits of the voice field are unique references for the measures. However, the voice quality at the physiologic limits is not representative of the voice as produced in singing or speaking. Measures which characterize the "hoarseness" of the voice yield important results with respect to the perturbation of the voice production (jitter, shimmer, additive noise). The perturbation measures evaluate the laryngeal function at defined points in the frequency--intensity area. However, in forte phonation, the natural perturbation is reduced, in piano phonation, the perturbation is increased, and the results cannot be interpreted in relation to the perturbation magnitude within the voice field. Besides, the measurement of perturbation requires digital signal processing. If EMG data are used for the voice field, as it is shown for the M. vocalis, the voice field reveals interesting relationships between acoustic and physiologic features. For instance, in the piano phonation, the EMG signal power is constant on a low level. In the forte phonation, in the chest register, the EMG signal power shows a medium level and a high level in the head register. In the falsetto, however, the EMG signal power is low.(ABSTRACT TRUNCATED AT 250 WORDS)