-> think the device can be used for this purpose as its quite common.
-> As for the claims that it  "detects heartbeats", I would simply say
-> that is probably media innaccuracies at work. It does detect sounds,
-> but I really doubt the sounds are heartbeats.  The people who use
-> high gain audio for rescue
Dear Scott:
  Well, yeah, but they weren't just saying it, they were showing it. Again, 
the fellow from Lawrence Livermore who developed this circuit, a Mr. McEwan 
(and I'm not sure on this spelling) protrayed it as radar, not an extremely 
high gain audio circuit. One scene showed the TV reporter on one side of the 
concrete slab, with the device and its operator on the other side. As the two 
conversed, a 'scope attached to the output of the device displayed a cardiac 
rhythm. A high gain audio circuit would be swamped by the level of the 
conversation.
  I'll be the first to say I'm unsure of the device's method of operation, 
but I'm hoping someone in this echo can set me straight.
  Yours, Blair
--- InterEcho 1.18
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