Magnets could help throat-surgery patients speak again

The removal of the larynx, caused by diseases such as throat cancer, means that patients permanently lose their voice.

Currently, the most common technique for speech restoration is to place a silicone valve in the throat that diverts air from the lungs and makes it vibrate, generating speech - but fluid created naturally in the body tends to clog the unit after three or four months causing it to fail.

Alternatives include the use of an electro-larynx that requires a handheld device to create a sound, but patients complain that the results sound electronic and can be hard to understand.

Working with colleagues at the Hull and East Yorkshire NHS Trust and Sheffield University, the researchers at Hull have developed a new system that could eventually recreate the patient’s own voice artificially following surgery.

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

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

The experiment demonstrated a recognition rate of 98 per cent, sufficient to provide commands and instructions. In time it is hoped that a bespoke speech synthesiser could be developed for each patient by making use of recordings of speech recorded prior to surgery, reducing the need for an artificial voice.

Dr James Gilbert from the Department of Engineering, who is leading the project, 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,’ he added.

’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,’ he concluded.

The project is being funded by grants from The Henry Smith Charity and Action Medical Research.