A critical appraisal of auscultation of human joints.

Auscultation of human joints is a rarely practiced art. Many attempts have been made to develop a technique with objective parameters but none are sufficiently sensitive for clinical use. This article reviews the history of auscultation as applied to human joints. An acoustic system was critically evaluated and attempts were made to exclude skin friction and ambient noise. Human joint sounds were found to be at the low end of the acoustic range. The microphone was a poor transducer in terms of frequency and dynamic sensitivities for use with human joint emission because of the large acoustic impedance. Many of the problems encountered by workers in this field might be due to failure to appreciate the limitation of detection apparatus.