Hey guys I had an idea. To me it seems like on a computer keyboard each key on the numberpad sounds slightly different. I was thinking what if you recorded someone typing in their password on the keypad with a mic that was hooked up to an op amp and you also recorded yourself pressing all they keys for identification purposes.

IF the Mic was sensitive enough and the gain on the op amp was appropriate could it be possible for sound analyzer software to distinguish the keypresses enough to determine which keys were pressed.

I am not trying to hack anyone but rather was arguing with my friend after I was joking about figuring out his password and got this random idea. Thanks, DGIKuljot