Anatomic variations of the auditory canal pertaining to the fit of stethoscope earpieces.

Leaks in the enclosed acoustical system of the stethoscope reduce its efficiency and can greatly impair the physician's ability to detect the faint murmurs of early valvular heart disease. The results of this study demonstrate a high degree of variability in size and configuration of the external auditory meatus among different individuals. It appears probable that both excessive leaks and also partial or complete occlusion of the acoustical pathways commonly result with the use of standard stethoscope earpieces.