In the future, the voices you hear in your head will actually be there.
The reason: two students at the Royal College of Art in London have designed a phone that fits inside a tooth.
The device picks up signals from a radio receiver and uses a tiny vibrating plate to convey them as sound along the jawbone to the ear.
The designers, James Auger and Jimmy Loiseau, said the phone could be implanted in a tooth during routine dental surgery.
At present, the tooth phone is only a model and lacks the communications chip to turn it into a functioning device.
But Auger said the technology to turn it into a working phone already exists and it would be a simple matter to build the relevant chips for the gadget.
He suggested that if the tooth phone is developed, it could be used to receive up-to-the-minute information about stock prices and help coaches communicate with players on the field.