An effect of body massage on voice loudness and phonation frequency in reading.

The effect of massage on voice fundamental frequency (F(0)) and sound pressure level (SPL) was investigated. Subjects were recorded while reading a 3-min passage of prose text. Then, a 30-min session of massage was administered by a trained naprapathy therapist. Sixteen subjects were given the massage, while 15 controls rested, lying down in silence for the same amount of time. The subjects were then recorded reading the same passage again. The F(0), and SPL averages across the whole passage were measured for the pre- and post-treatment recordings. In the post-massage recordings, subjects had lowered their F(0) by 1.1 semitones and their SPL by 1.0 dB, with very high statistical significance. The drop in F(0) was somewhat larger for the males than for the females. The control subjects showed no effect at all.