The Effect of Head Flexion/Extension on Acoustic Measures of Singing Voice Quality

A study was undertaken to identify the effect of head flexion/extension on singing voice quality. The amplitude of the fundamental frequency (F0) and the singing power ratio (SPR), an indirect measure of Singer's Formant activity, were measured. F0 and SPR scores at four experimental head positions were compared with the subjects' scores at their habitual positions. Three vowels and three pitch levels were tested. F0 amplitudes and low-frequency partials in general were greater with neck extension, while SPR increased with neck flexion. No effect of pitch or vowel was found. Gains in SPR appear to be the result of damping low-frequency partials rather than amplifying those in the Singer's Formant region. Raising the amplitude of F0 is an important resonance tool for female voices in the high range, and may be of benefit to other voice types in resonance, loudness, and laryngeal function.