"The sound of silence": when the brain doesn't hear.

Cognitive impairment is one of the leading causes of disability worldwide and it affects about 6.5% of the population over the age of 65. Hearing impairment is a significant health problem and a possible cause for dementia. Preventing hearing loss or at least correcting it by the use of acoustic prosthesis may reduce the onset of dementia in old age. Indeed, hearing loss has been proposed as a risk factor for dementia, even if the mechanisms that correlate the two diseases are not yet fully understood. It can accelerate existing mild cognitive impairment by increasing the cognitive burden and/or exhausting existing cognitive compensatory strategies, and it could also increase social isolation. Peripheral hearing impairments and Central Auditory Processing (CAP) dysfunction should both be evaluated. Indeed, although peripheral auditory function impairment is perhaps the primary pathological component of early age-related hearing loss (ARHL), CAP dysfunction becomes increasingly important in the later stages of ARHL. The assessment of peripheral hearing function includes self-reporting and some screening tests (such as the 10-item Hearing Handicap Inventory for the Elderly - Short Form), a first-level clinical assessment for hearing loss (such as spoken voice or finger friction tests), audiometric screening tests (portable audiometers, portable audio) and diagnostic audiometric tests (such as pure tone audiometry in a soundproof booth to test the acoustic threshold). The present article focuses on the possible connection between sensory deprivation and the development of cognitive impairment in late age. The use of hearing aids and cognitive training could help delay or prevent the onset of cognitive decline. Furthermore, the use of hearing aids can be an effective tool not only to minimize perceived disability in older individuals, but also to reduce the caregiver's burden by improving the patients' ability to communicate.