Laryngeal closure pressure during phonation in humans.

We investigated the laryngeal closure pressure during sustained phonation in five healthy adult men with no pathological lesions in the glottis using a round pressure transducer with a diameter of 10 mm and a thickness of 1 mm. The transducer was placed between the vocal processes through the mouth. Subjects were asked to utter a sustained phonation of the vowel sound /eh/ at varying pitch and intensity in modal register. The laryngeal closure pressure ranged from 0 to 200 cmH2O. At a comfortable pitch and intensity, the pressure was below 50 cmH2O. The pressure was correlated with pitch, but not with intensity.