A simple electronic stethoscope for recording and playback of heart sounds.

UNDERGRADUATE TEACHING of cardiovascular physiology often involves lectures on heart sounds. To complement these lectures, online resources are commonly used. The audio files of heart sounds are available as free downloads on the internet from websites of stethoscope manufacturers such as Thinklabs (http://www.thinklabsmedical.com/sound-library.html) and Littmann (http://solutions.3mindia.co.in/wps/portal/3M/en_IN/ Littmann/stethoscope/education/heart-lung-sounds/). The auscultation assistant website of the University of California-Los Angeles (http://www.wilkes.med.ucla.edu/inex.htm) is also an excellent resource for abnormal heart and lung sounds. Heart sounds can also be demonstrated during practical sessions (1). It is, however, interesting for students to see the recording and playback of heart sounds during lecture. Described below is a simple electronic stethoscope that can be used for performing such recordings. It is a modified version of the stethoscope microphone described in a YouTube video available at http:// www.youtube.com/watch?v iqjxOapIKbE. This electronic stethoscope will be useful for departments that do not have phonocardiographs, electronic stethoscopes, echocardiography, or ready internet access.