Transglottal pressures in professional singing.

Using high-frequency miniature pressure transducers, direct measurements of sub- and supra-glottal pressure are taken on two sopranos singing high notes, in a range where F1 is close to F0. When the peak in supraglottal pressure occurs well into the open phase of the glottal cycle, the instantaneous transglottal pressure approaches zero. When this peak occurs later in one of the subjects as a feature of the vibrato modulation, the transglottal pressure even drops appreciably below zero. The implications of these findings for the glottal volume velocity waveform, as well as for the singer's experience of the second "passaggio" point, are discussed.