“Headphones”, an art piece by Andre Avelas employs 1,000 individual headphone sets where 960 work as speakers and 40 as microphones in order to create a continuous feedback loop that can be controlled on a nearby mixer. The project included an amplification circuit that added more hum to the feedback chain. Pretty interesting use of commonly found speakers. Check the link below for a sound sample to be posted soon.

Photos of the project – Link, artist site, [via]