Are you sure this is a "Listening Device" and not a "Tracking Device"? Perhaps the name of the article ought to be changed? Am138 18:34, May 6, 2010 (UTC)
Possibly, but we do hear the heart beating, so it is "listening". DEMORGAN 20:57, May 6, 2010 (UTC)
Hmm...I can only assume it does both then! =P 86.26.77.157 13:37, May 9, 2010 (UTC)