Lung sound intensity variability in normal men. A contour phonopneumographic study.

We describe and demonstrate a new lung sound measurement and display technique by which contour maps of lung sound intensity may be constructed. Using this technique, we have studied the lower posterolateral chest wall of ten healthy subjects. The data revealed an unexpectedly high degree of intersubject and intrasubject variation. The reason for this variation is obscure but probably relates to the basic mechanisms of production and transmission of lung sounds.