I recently attended a lecture given by Professor Kelly Tremblay (University of Washington) who linked behavioural and electrophysiological research to suggest that we need to rethink how auditory rehabilitation is delivered. An ageing population is resulting in a number of challenges that may not be solved using traditional methods.
Many patients complain that ‘I can hear you but can’t understand you’, they struggle with noise, multiple talkers, strangers accents and fast paced speech, which leads to the patient avoiding those situations by withdrawing from them. Ageing, impacts the quality of the ‘bottom up’ signal transfer (How the sound is transmitted from the ear to the brain), this we know, but electrophysiological investigations have shown that impaired perception is due in part to a decline in neural synchrony as a result of ageing on the central auditory system. The research suggests that deterioration occurs from the age of 35 and results in a ‘signal distortion’. This processing deterioration (time locking ability) was not improved with amplification even though near normal hearing thresholds were achieved.
As an audiologist I found this investigation very insightful. It indicated that due to these central changes, hearing aids may not be enough on there own to overcome hearing problems in increasingly older populations. Programming hearing aids for ageing patients will require different compression and gain strategies. It also supports the need to fit amplification sooner rather than later, to limit the impact of auditory damage on the brain. Earlier intervention for middle aged populations to ensure people are more aware of the issue, is also an important consideration. Greater understanding of these processes will lead to improved hearing aid prescriptions and rehabilitation techniques.