Imagine boosting your mobile's battery simply by the power of speech!
Electrical engineers have worked out a way of turning sound into energy, which would mean your mobile phone would be powered by your conversation, music or just background noise.
At a University in South Korea, scientists have been exploring different ways to make energy from our environment.
The method uses small strands of zinc oxide which is trapped between electrodes. When a sound wave hits the top layer, the zinc oxide wires compress and release which makes an electrical current.
The process could also be used to build walls near roads that absorb the sound from passing traffic, which would reduce noise levels as well as making electricity.