Supra-and Sub-Neoglottic Pressure in Esophageal Speech

Abstract

Supra- and sub-neoglottic pressures were measured to clarify the mechanism regulating esophageal speech in ten laryngectomized patients whose vocalization depended entirely on esophageal speech. All were told to try to pronounce the vowel /a/ under various conditions, and some were told to pronouce voiced and voiceless consonants. The following were recorded simultaneously: (1) speech signals, (2) sound via a contact microphone located above the clavicle, (3) supra-neoglottic pressure, and (4) sub-neoglottic pressure. Two sets of miniture pressure transducers, fixed to a fiberscope, were used to measure pressure. The following results were obtained.
Neoglottis averaged 20+/-0.5 cm from the entrace of the nose. The sub-neoglottic pressure was higher than the supra-neoglottic pressure during phonation of the vowel /a/; good speakers could maintain a comparatively uniform sub-neoglottic pressure waveform. During esophageal speech by aspiration, some patients showed a slightly negative sub-neoglottic pressure before it increased. The sub-neoglottic pressure rose higher during loud phonation of /a/ than during comfortable phonation. During sustained phonation of the vowel /a/, good esophageal speakers could maintain the peak sub-neoglottic pressure fora longer time and could control the rise in sub-neoglottic pressure better than could poor speakers. The supra-neoglottic pressure was higher during phonation of a voiceless consonant than during of a voiced consonant.
Direct measurement of supra- and sub-neoglottic pressure seem useful in clarifying the mechanism of esophageal speech.