Intraoral air pressure of alaryngeal speakers during a no-air insufflation maneuver.
Intraoral air pressure was recorded during the production of the consonant cognate pairs /p/-/b, /t/-/d, and /s/-/z/ by eight esophageal speakers. These consonants were combined with the vowel /a/ to form CV, VCV, and VC syllables and produced under two experimental conditions: after the insufflation of air and without air insufflation. The purpose was to determine if the voiced-voiceless pressure difference associated with the production of cognate pairs would occur in the absence of an insufflated air flow source. The results revealed that peak intraoral air pressure magnitudes were significantly greater following the insufflation of air than without it. Moreover, the voiceless consonants were generally produced with greater peak air pressures than the voiced consonants under both experimental conditions, although not all contrasts were significantly different. Finally, peak air pressure magnitudes were significantly more variable in the air insufflation condition. The finding that the esophageal speakers exhibited a pressure difference relative to voicing in the absence of an insufflated air flow source provides support to the concept that intraoral air pressure may be an important variable in regulating and controlling consonant production.