The NHS spends approximately £60 million on hearing aids each year. However, there are no well-established methods to test hearing aids from different manufacturers to predict which ones provide the best sound quality or speech intelligibility for users. Such methods would help the NHS to provide, and allow hearing aid users to obtain, the best available hearing aids.
To thoroughly compare different hearing aids, what is called a ‘randomised controlled study’ of sound quality and speech intelligibility would be needed. These studies are expensive and time consuming, and would have to be repeated every time a new hearing aid was added to the market. Developing objective measures that can reliably predict sound quality or speech intelligibility would allow the NHS to rapidly identify high-performing hearing aids, and avoid potentially spending millions of pounds on lower quality hearing aids.
In Robyn’s project, she will develop objective measures for hearing aid testing that can predict sound quality and speech intelligibility for people with mild to moderate hearing loss.
She will test a combination of factors suggested by previous research to best predict sound quality or speech intelligibility for listeners with hearing aids. She will record these factors for different hearing aids, and also ask small groups of hearing aid users to rate the quality of speech from them. She will use a ‘neural network’ (a computer system that can learn patterns in data) to link the objective hearing aid measures with user ratings of sound quality, building on previous work at the University of Southampton on predicting music quality in hearing aids.
Developing objective measures that can predict sound quality and speech intelligibility for hearing aids would allow providers of hearing aids, such as the NHS, to make sure they were selecting and providing the best hearing aids.
Such measures would also help to speed up the development of new hearing aid technology as they would allow manufacturers to optimise the design and features of hearing aids quickly and simply.