Airflow control by auditory feedback: respiratory mechanics and wind instruments.
Science 1966 Nov; 154(3750):797-799
The use of auditory feedback in controlling airflow during measurements of the flow resistive (mechanical properties) of the lungs and airways was discussed. The mechanical properties of the lungs can be measured by determining the transpulmonary pressure required to overcome viscous resistive forces in the airways and lungs. During spontaneous breathing, transpulmonary pressure, pulmonary volume, and airflow rates vary cyclically with time. If the airflow rate could be maintained, the mechanical properties of the lungs could be evaluated from plots of the pressure volume changes (PV diagrams) of the lungs. It was thought that tones produced by a soprano recorder incorporated into the breathing circuit could help human subjects regulate inspiratory and expiratory airflow rates at the constant preset levels required to determine the needed PV diagrams. A soprano recorder requires only a low constant driving pressure, on the order of 1 to 7 centimeters water, and a low, constant airflow rate, around 0.05 to 0.1 liter per second, to produce tones of increasing pitch. Because recorders use a fixed slit and edge for tone production and do not require embouchure, they can be played through tubing and flow meters and only minimal practice is required to produce a tone. An experimental arrangement was described which incorporated a soprano recorder in the breathing circuit of a system used for constructing PV diagrams to analyze the mechanical properties of the lungs. The subject, wearing a noseclip and sitting in an air conditioned plethysmograph, breathes through a mouthpiece which is connected to the recorder by way of a three way stopcock. The subject is asked to play a soft tone on the recorder and the proper airflow is obtained by listening to the tone. Preliminary results obtained with the setup using volunteers inhaling a histamine (51456) aerosol have shown that the bronchoconstrictive effects of the histamine can be discerned from the PV diagram.
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Pulmonary-function-tests; Auditory-feedback; Laboratory-testing; Laboratory-techniques; Air-flow; Sound; Physiological-response
None John B Pierce Foundation Labor 290 Congress Avenue New Haven, Conn 06519
John B Pierce Fdn of Conn Inc, New Haven, Connecticut