My dish washer makes a tiny, feeble beep when it is done. I would like a device about the size of a hockey puck that will listen for this sound and then make a louder sound with a flashing light until I open the dish washer (angle sensor magic thingy) or push a button. It would have a magnet on it, and would be rechargeable.
Ideally, it could be programmed by pushing a button while the dishwasher sound plays. Maybe it could sit idle for a number of minutes and then pick the likeliest sound (above a certain frequency).
The light would make it useful for really deaf people.-- nomocrow, Feb 23 2012random, halfbakery