RESPONSIVENESS OF SINGLE AFFERENTS IN THE INFRAORBITAL NERVE TO ORAL AIR PRESSURES GENERATED BY CONSONANTS

The responsiveness of receptors supplying the oral mucosa to air press ures generated during consonant production was investigated to obtain information about hypothetical mechanisms underlying speech deficits. The delay between the onset of the neural discharge and the pop puff o f phonation (mouth-exit pressure) for /pa/ production was significantl y shorter and less variable than it was for /ta/ and /ka/ production, suggesting that the discharge is more closely coupled to the onset of /pa/ production. The data were interpreted to imply that single fibers of the infraorbital nerve respond to the build-up of oral air pressur e during /pa/ production. This, and similar sensory information, may b e used by the central neural mechanisms which monitor and control the air pressures required for phonation.