Recording Heart Sounds
Our site, www.evansvilleheartcenter.com maintains a "Heart Sounds" gallery, which has audio clips of a
variety of heart murmurs and artifical heart valve sounds recorded
utilizing a electronic stethoscope (as a microphone), and a Sharp
MD-MT15 minidisc recorder. The sounds clips were then downloaded to a
PC and sampled and encoded utilizing Sound Forge 4.5. These heart
sounds are very low frequency intensive, and of interest, I could not
get Sony minidisc equipment (I think because of "automatic gain
control") to accurately record the sound. The Sharp unit has "manual"
gain settings and a smallish VU meter incorporated into the display
panel, that allowed the gain to be set manually.
Jay Tuna, M.D.
Evansville Heart Center
Note: The Sony's also have a manual gain control mode, it is entered by
pushing the record slider and holding it for 2 seconds. -eaw