Abstract:
Relationships among average subglottal pressure, average glottal airflow, and glottal adduction (vocal process gap), variables related to glottal competence, were obtained for one human subject. The data define the pressure-flow-adduction space. Results are similar to those of a study using excised canine larynges [Alipour et al., ``Pressure-flow relationships during phonation as a function of adduction,'' J. Voice (in press)] especially for the differential flow resistance as a function of adduction. For set values of adduction, glottal flow resistance increased by about 2.5 times between subglottal pressure values of 5 and 15 cm H[inf 2]O. At set values of subglottal pressure, flow resistance increased by a factor of approximately 9.5 between pressed and breathy phonation. Any particular flow resistance value does not predict a particular adduction value due to the dependence on subglottal pressure. However, a particular subglottal pressure, glottal flow pair appears to predict a particular adduction level. Subglottal aerodynamic power increases with subglottal pressure at set levels of adduction, increasing by a factor of about 3.7 between 5 and 15 cm H[inf 2]O. For a specific value of subglottal pressure, aerodynamic power increases as adduction decreases. [Work supported by NIH Grant No. P60 DC00976.]