Neural and cognitive factors in healthy and impaired hearing

Although young healthy listeners understand speech effortlessly, older people and those with hearing loss sometimes struggle to hear well, especially in noisy situations. Our research aims to understand the neural bases of these difficulties, both in those with audiologically normal hearing and deaf people whose hearing has been restored by a cochlear implant (CI). In particular we explore ways of overcoming some of the limitations of cIs so as to allow a wider range of patients to hear well. To do this we combine behavioural and EEG measurements with intra-operative recordings and clinical observations.

Understanding speech is sometimes easy and straightforward, but becomes increasingly difficult in the noisy and cognitively demanding environments that we encounter in everyday life. People with hearing loss have particular difficulty in understanding speech in these environments, experience reduced access to education and employment, and are at greater risk of dementia in later life.. We identify the fundamental limitations on speech perception for normal-hearing (NH) listeners and, particularly, for people whose hearing has been restored by a cochlear implant (CI), and create the methods, tools, and computational models necessary to understand and improve hearing. One example comes from the development of novel EEG equipment and methods, which, together with complementary psychophysical techniques, allow us to identify the neural bases for auditory perception and for the limitations experienced by CI listeners. These measures are combined both with precise single-neuron recordings from animals and with cognitive manipulations in humans that, together, allow us to explore the relationships between sensory deprivation and cognitive capacity. Our multi-disciplinary approach is also applied to investigations of the plasticity of sensory functioning and speech perception, as the newly implanted CI patient’s brain adjusts to the restoration of sensory input. We benefit from a close partnership with clinical colleagues at Addenbrookes hospital, including a monthly clinic for poor-performing CI users that stimulates translation both to and from our basic scientific research, and from collaborations with and support from CI companies. More widely we engage with a critical mass of auditory and language researchers within the CBU (Davis, Halliday, Goehring, Lambon Ralph) and throughout the Cambridge Hearing Group:

https://www.hearing-research.group.cam.ac.uk/