About this Research Topic
Hearing loss is the second highest cause of disability in the world, affecting 1.33 billion people with 90% of cases being due to age-related hearing loss (ARHL). Ageing affects the two key components of the auditory system involved in processing incoming auditory stimuli: the peripheral and the central hearing systems The peripheral hearing system consists of the peripheral components of hearing, namely the cochlea, middle ear and outer ear. The central hearing system encompasses the central auditory pathways and influences the way incoming auditory stimuli are perceived and understood, namely central auditory processing. Peripheral hearing loss affects both the auditory processing of speech sounds and the higher-level cognitive functions required to process linguistically demanding sentences.
Evidence from both cross sectional and longitudinal studies confirmed the existence of an association between peripheral hearing impairment and cognitive impairment in older adults. Several recent studies have also reported an increase in the risk of incident dementia among older adults with age-related peripheral hearing loss and risk of incident Alzheimer’s disease (AD) (1.20 increase per 10 dB loss; 95% CI 0.94-1.53).
The central hearing system is crucial for understanding speech in background noise, spatial processing and integrating and separating binaural auditory information. In some individuals, difficulties experienced during comprehending speech in noisy backgrounds or competing speakers could be related to central auditory processing difficulties rather than peripheral hearing deficits. Results from a number of longitudinal studies suggest that changes in central auditory processing skills, in the absence of a severe peripheral hearing loss, are also associated with high incidences of cognitive decline and AD dementia. Similar findings have been observed in Parkinson’s disease as well. Although, a handful of studies have demonstrated that individuals with central auditory dysfunction were at a significantly increased risk for dementia, exact mechanism behind the comorbidity of declining cognition and central auditory processing deficits is yet to be determined.
This Research Topic invites the manuscripts that investigate the association between both peripheral and central hearing loss and cognitive impairment in older adults with neurodegenerative diseases.
Keywords: aging, hearing loss, presbycusis, alzheimer’s, dementia
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