Zur Frage der quantitativen Bewertung der Tragf�higkeit der Stimme

Abstract

The efficiency of the voice is said by Winckel (1953) to be especially determined by the energy of the spectral area around 3000 cps. Therefore, Winckel has repeatedly recommended selective measurement of the 3000 cps-component of the voice spectrum for the objective evaluation of vocal efficiency. As this proposal has not yet been supported by comparative studies, we asked 41 normal subjects and 24 professional singers to phonate several tones (vowel “a”) at different frequencies (c [131 cps]; g [196 cps]; c1 [262 cps] in males and c1 [262 cps]; g1 [392 cps]; c2 [523 cps] in females) and intensities (65, 75, 85 and 95 dB SPL). In all voice samples we compared the formant energy in the spectral area of 2500–3000 cps with the amplitude of a lower frequency area (800–1300 cps), which about corresponds to the area of the second formant, by means of filter analysis. Results show that in all persons tested for this study the relative amplitude of the 3000 cps-component grows with increasing vocal intensity, but diminishes with increasing vocal pitch. At intensity levels of 75 dB and 85 dB SPL singers showed at all three pitch levels (except the tone c2 [523 cps] at 75 dB SPL in females) significant smaller differences between the amplitudes of both the selected formant areas, i.e. relatively stronger partials around 3000 cps, than normal subjects. At the intensity level of 65 dB the differences between vocally trained and untrained groups were less pronounced. This finding supports Winckel's suggestion that the efficiency of a voice can be evaluated quantitatively by the measurement of the relative amplitude of the 3000 cps area, but also reveals that for reliable results such measurement has to be done at certain pitch and intensity levels and under constant test conditions only.