sound to electricity

[donkey]

hey guys,
a while ago I wrote asking if anyone knew of a circuit to convert noise into electricity. I have found many examples of it but am still stuck on finding a circuit diagram. http://www.gizmodo.com.au/2011/11/sound-powered-leds-turn-screams-into-power/
here is an example of what i have found. I know I will produce very samll amounts of energy but would still like to find a diagram to help me in a theory I have. thanks
phil

 

[Harald Kapp]

Google "Energy Harvesting". There are a few specialized circuits out there to charge a battery from very small amounts of energy. A dynamic microfone could be used as source.

Harald

 

[KrisBlueNZ]

FYI an interesting video covering two Linear Technology devices for energy harvesting from thermoelectric and solar cell sources: