Magnets provide key to overcoming silent legacy of throat diseases

Patients who have their larynxes removed for diseases including throat cancer, permanently lose their voices.

However researchers from Hull and Sheffield universities, together with doctors in Hull, are developing a device that could one day recreate the organs artificially.

The most common existing technique for speech restoration is placing a silicone valve in the throat to divert air from the lungs to make it vibrate and generate speech. However fluid created naturally in the body tends to clog the units after a few months causing them to fail.

Alternatives include using electro-larynxes and handheld devices to create noise, but patients complain the results sound electronic and can be hard to understand.

The new technique involves placing a series of magnets inside the mouth to create a moveable three-dimensional magnetic field. This can be analysed and used to identify speech patterns and particular words.

During an initial trial, magnetic sensors were mounted on frames worn by those taking part in tests. A database of 57 words was created and, using measurements taken from the magnetic sensors, were matched to recreate speech.

The experiment saw recognition rates of 98 per cent – sufficient to provide commands and instructions. In time, researchers hope the technology could use recordings taken before surgery to develop speech synthesisers reducing the need for artificial voices.

Project leader James Gilbert, of Hull University's department of engineering, said: "The possibilities for this new technology are immense and could eventually see patients literally given their own voice back once they have undergone surgery.

"It is clear that current techniques and methods available to patients are limited, with systems failing too soon or sounding too artificial. Patients already have a lot to cope with during their treatment so it's important they can achieve a degree of normality once they have undergone surgery.

"With further work our research could completely change the way operations such as laryngectomies are considered by patients and allow them to lead normal lives without drawing attention to their condition."

The project is funded by the Henry Smith Charity and Action Medical Research.