On the relation between speech understanding and neural processing

It is well established that hearing capabilities decline with ageing and/or following noise exposure. Clinically, hearing abilities are assessed by pure-tone audiometry (thresholds). However, some normal hearing (NH) listeners report great difficulties in understanding speech, particularly, in environments with background noise despite having normal audiometric thresholds. This problem is referred as Hidden Hearing Loss (HHL). One of the main factors associated with HHL, is the selective loss of high-threshold auditory nerve fibres. This selective neural damage may reduce the ability of the brain to encode the fine temporal fluctuations conveyed by sounds, and so decreasing speech understanding, particularly in the presence of noisy. People with HHL are affected in everyday communication specially in noisy situations. The aim of this project is to establish a method to assess HHL using objective electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and behavioural tasks. By such means will we be able to link neural representation and communication deficits.