RESPIRATORY AND LARYNGEAL FUNCTION-ASSOCIATED WITH EXPERIMENTAL COUPLING OF THE ORAL AND NASAL CAVITIES

Three experimental openings (10 mm(2), 20 mm(2), 30 mm(2)) were placed one at a time in a man's palatal obturator at a location approximatin g the junction of the prepalate and the palatal shelves. The man's lar yngeal and respiratory function were examined during his production of a series of CV syllables [pa] repeated at a comfortable and loud voca l intensity for each of the th ree experimental conditions. Two more c onditions, in which the subject's obturator was not altered (no hole) and in which no obturator was worn, were also included for study. Lary ngeal and respiratory function adjustments were most apparent during t he 30 mm(2) hole size and no obturator conditions. Laryngeal adjustmen t, as measured by fundamental frequency, was the most identifiable. A respiratory adjustment, which involved the expenditure of more lung vo lume as nasal airflow leakage increased, was also observed. These obse rvations imply an active physiologic adjustment rather than a passive response to aberrant oronasal coupling.