Dentist's drill now music to your ears

Patients terrified by the whirring sound of the dentist's drill could benefit from a new gadget that cancels it out. London scientists say they have come up with a device which not only filters out the sound but allows people to listen to their own music too.

The gadget contains a microphone and a chip which analyses the incoming sound wave and then produces an inverted wave to cancel out the unwanted noise. Patients hook up their MP3 player to the device, then plug their headphones into the gadget.

They can still hear the dentist talking, as the device locks on to the sound waves, removing them even if the pitch changes.

"Many people put off going to the dentist because of anxiety associated with the noise of the dentist's drill," Professor Brian Millar of King's College London said. "But this device has the potential to make fear of the drill a thing of the past.

"The beauty of this gadget is that it would be fairly cost-effective for dentists to buy."