[What is the value of measuring "singer's formant" in phoniatry?]

The singing formant is the product of an articulatory gesture. Devices for phonetogram measurement often claim the ability to determine it. However, they measure rather the overtone content or the noise of the voice than the formant. Moreover, the voice efficiency (ratio of the sound pressure in the frequency band 2-5 kHz to the total sound pressure), also measured by these devices, is not defined in a physical or physiological sense. Such measurement does not evaluate the efficiency of the vocal apparatus.