Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The variation of acoustic attenuation with lung density was determined in experimental studies on seven healthy human volunteers, using a change of lung volume as a means of varying lung density. White noise between 50 and 680 Hz was introduced into the mouth and the transmitted signals were recorded with four microphones on the posterior chest wall (left/right, top/base) at 24, 40, 60 and 80% of total lung capacity. The change in lung volume had a frequency-dependent effect on acoustic attenuation in all subjects. A frequency between 177 and 243 Hz was identified, where altering the lung volume between 24 and 80% of total lung capacity induced a change in attenuation of only 1.0 (+/-0.5) to 2.7 (+/-1.8) dB, while at a frequency of 364-436 Hz marked variations in attenuation 8.9 (+/-2.0) to 21.5 (+/-4.8) dB occurred with similar lung volume changes.

Type

Journal article

Journal

Physiol Meas

Publication Date

02/2001

Volume

22

Pages

233 - 243

Keywords

Acoustics, Adolescent, Adult, Functional Residual Capacity, Humans, Lung Volume Measurements, Male, Respiratory Sounds