Phonation into a tube as a voice training method: acoustic and physiologic observations.

Phonation into narrow glass tubes has been used as a voice training method. The present study examined phonatory and voice quality during and after tube phonation. The methods used were (a) electromyography with surface electrodes, (b) a dual-channel electroglottography from which the vertical larynx position was derived and (c) inverse filtering of the acoustic signal of vowel samples produced before and immediately after the exercise. Phonation into a tube seemed to cause a tendency to heighten the vertical laryngeal position. For female subjects (n = 3) the tube exercise tended to lead to increased vocal effort in vowel production after the exercise and, in contrast, to a tendency for a more relaxed voice production for the males (n = 2).