Nervous dental patients could benefit from new technology that masks the sound of the dentist's drill.
The high-pitched whine has long plagued the cavity-laden, but the new device will allow the patient to listen to their own music and still be able to hear the dentist's voice. The drill noise, however, will be cancelled out.
It works by turning all sounds into a digital signal and, in a similar way to noise cancelling headphones, uses a digital signal processor to analyse incoming sounds.
Adaptive filtering then locks onto the relevant sound waves and removes them using an inverted sound wave.
What time is it? Tooth-hurty
Researchers at the King's College London, London South Bank University and Brunel University have been working 'round the clock on the device and are now looking for a manufacturer to put it into production.
Professor Millar of King's Dental Institute had the original idea, inspired by Lotus's efforts to reduce in-car road noise while still enabling drivers to hear emergency sirens.
He said, "The beauty of this gadget is that it would be fairly cost-effective for dentists to buy, and any patient with an MP3 player would be able to benefit from it, at no extra cost."