Voice is a critical indicator of both physiological and psychological well-being and as such offers a particularly acute and effective gauge of physical and mental health. Rodenburg describes it as follows:
Breath, vocal release, range, ‘placing’ resonance and speech are equally related. So when I speak of the voice I am really speaking of an entire physical network. Everything is connected to everything else, everything works with everything else.(Rodenburg, 1992, p20) The voice therefore serves to reflect not only the individual’s emotional state, their personality and their physical state, but also their previous life history and experience. This point is usefully summarised by Mathieson (2001): ‘In adulthood the voice eventually provides an amalgam of personal information’.