Studio Toer's amplifier uses kinetic energy to power mobile audio. Called Bongue it is a "physical amplifier of mobile audio."

Suspended from a speaker that acts as a weight, an iPod Nano's audio signal is amplified by a slowly descending counterweight. Says Studio Toer, "The dynamic qualities give it a multi-sensorial experience for daily life."

"When Bongue is fixed it's only amplifying the sounds from the music-device itself."

"When you start moving the arm it will give energy to the amplifier and by that it will increase the volume of the musicplayer."

+ studiotoer.com