AuthorBailey, Elizabeth Fiona
AdvisorHoit, Jeannette D.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThis investigation was designed to examine speech production, the motion of the chest wall, and breathing-related perceptions under a condition of heightened respiratory drive. Ten healthy young men were studied during spontaneous breathing and during speaking in three gas conditions: room air, air delivered from a pressurized tank, and a gas mixture high in carbon dioxide (7% CO₂) delivered from a pressurized tank. Magnetometers that transduced diameter changes of the rib cage and abdomen were used to study chest wall motion. Subjects also reported their breathing-related perceptions. Results indicate that chest wall behavior during spontaneous breathing and speaking did not differ between room-air and tank-air conditions, but differed substantially in the high-CO₂ condition. In the high-CO₂ condition, spontaneous breathing and speaking usually were characterized by larger lung volumes, larger rib cage volumes, higher breathing rates, longer expiratory times, and higher expiratory flows than in the two air conditions. Further, speaking in high-CO₂ was characterized by shorter speech duration, fewer syllables per breath group, and greater average lung volume expenditure per syllable compared to speaking in air. In high-CO₂, subjects reported a range of breathing-related percepts including "breathlessness," "effortful breathing," and "gasping for air." Without exception, speaking in high-CO₂ was judged by the subjects to be more difficult than breathing in high-CO₂.
Degree ProgramGraduate College
Speech and Hearing Sciences