Internal voice sensitivities in opera singers.

To control their voices, singers rely not only on auditory feedback but also on proprioceptive feedback supplied by internal voice sensitivities (IVS). IVS, which are essentially pallesthetic (vibratory) and kinesthetic (muscular), provide singers with precise landmarks for controlling their emission. This means of control is more reliable than auditory feedback in which the voice is substantially modified by the acoustics of the environment.