Level Headed – EL Wire Decorated Headphones via HaD. yardleydobon writes -

I modified the inverter from a T-qualizer shirt to respond to the audio signal from my mp3 player instead of sound and used the inverter to drive electroluminescent wire attached to my headphones. The inverter lights up different colors of EL wire depending on the loudness of the music I’m listening to. The headphone decoration looks like a signal level meter.