Respiratory and laryngeal responses to an oral air pressure bleed during speech

By J.E. Huber and E.T. Stathopoulos

It is widely believed that the speech system components (respiratory, laryngeal, and supralaryngeal) interact in a complex manner during speech. However, few experimental studies have demonstrated interactions among all three components by collecting data simultaneously. The current study was designed to describe the nature of the interactions among the speech system components in normal adults, using a perturbation paradigm. Speakers produced syllable trains of [pa] in three conditions: 1) “tube no bleed” in which one end of the bleed tube was blocked, 2) “tube with bleed” in which both ends of the tube were open, allowing air pressure to leak out during the production of [p], 3) without the bleed tube. Measurements of respiratory kinematics, laryngeal and oral aerodynamics, and acoustics were made in all three conditions. The data demonstrated active compensations in the respiratory component to the loss of intraoral air pressure. The data suggested that although there was an increase in respiratory drive in the “tube with bleed” condition, subglottal pressure was held constant across the conditions, most likely by laryngeal component compensations. Data will be discussed relative to two perspectives of the goals of compensations: maintenance of aerodynamics of the vocal tract versus maintenance of perceptual adequacy.