[Vocal effectiveness in speech and singing: acoustical, physiological and perceptive aspects. applications in speech therapy].

OBJECTIVE: What is vocal effectiveness in lyrical singing in comparison to speech? Our study tries to answer this question, using vocal efficiency and spectral vocal effectiveness.

MATERIAL AND METHODS: Vocal efficiency was mesured for a trained and untrained subject.

RESULTS: According to these invasive measures, it appears that the trained singer uses her larynx less efficiently. Efficiency of the larynx in terms of energy then appears to be secondary to the desired voice quality. The acoustic measures of spectral vocal effectiveness of vowels and sentences, spoken and sung by 23 singers, reveal two complementary markers: The "singing power ratio" and the difference in amplitude between the singing formant and the spectral minimum that follows it. Magnetic resonance imaging and simulations of [a], [i] and [o] spoken and sung show laryngeal lowering and the role of the piriform sinuses as the physiological foundations of spectral vocal effectiveness, perceptively related to carrying power.

CONCLUSION: These scientifical aspects allow applications in voice therapy, such as physiological and perceptual foundations allowing patients to recuperate voice carrying power with or without background noise.