Developing objective tests of hearing fidelity for the hearing impaired.

Hearing-aid users often make statements such as ‘I can hear you, but I can’t understand you!’ These statements indicate that the listener has a near-normal ability to detect sounds (I can hear you) but is suffering from degradation in the acuity of their hearing (I can’t understand you!). Fitting a modern hearing aid involves adjusting the device based on feedback; either via the user indicating the quietest sound they can detect at different frequencies behaviourally, or by direct ‘objective’ measures of sound detection measured with electrodes on the scalp. Both these types of feedback estimate the ability to detect very quiet sounds. This approach is problematic for people with well- corrected hearing thresholds but who still have difficulties understanding speech
because neither feedback measure captures the whole clinical problem. Objective feedback information that measures hearing acuity would help solve this problem. 
In this project, we will develop objective measures of hearing acuity at normal listening levels. By measuring the brains response to above-threshold, complex, and behaviourally-relevant sounds, we will measure the accuracy with which various acoustic cues are distorted by hearing aids, and encoded by the brain. This research will provide an objective measure of hearing acuity, without requiring a behavioural response, that can be used to maximise the speech-understanding benefits that hearing devices provide.