It's always fun to control normal things using unusual methods, and a classic is the "clapper switch" - the method of controlling an item via clapping or other short, sharp noises. On example of this has been demonstrated by Instructables member helenbang - who uses a sound sensor with an amplifier to detect the required noise, and then have a servo physically move the light switch on and off. Although this may seem like a clunk method, it keeps younger people away from mains wiring and is still a lot of fun - for example
To experiment with audio sampling yourself you can make an easy start with a simple electret microphone board, and our Freetronics MIC: microphone and sound module is perfect.
The MIC: contains an integrated dual signal amplifier converts the sound to separate channels for pulse / frequency measurement, and sound volume (pressure) level. Designed to connect straight to an Arduino compatible microcontroller, Analog to Digital converter, or many other circuits. For more information and to order click here.