On the shelf today is this application for an "Input device, system and method, " which as mundane as that sounds, actually appears quite the contrary.

ENGADGET

Obviously such a device would only detect taps, not presses, and Sony has claimed a calibration method that the average user may not want to bother with.

ENGADGET: Sony patent claims touch force detection via microphone

In addition to other possible uses, Patwari wants to conduct research with doctors to test his method as an infant-breathing monitor, and, if it proves useful, develop it as a medical device that would need federal approval.

ENGADGET: Researchers use wireless network to monitor breathing, could save lives