Is hearing loss connected to dementia?

Recent studies have suggested that there could be a connection between hearing loss and the brain, meaning a greater cognitive decline into older age.

2005 estimates from the World Health Organisation (WHO) show that about 5 million people around the world suffer from profound hearing loss, while 50% of those over 65 are affected by age related hearing loss, presbycusis.

Professor Frank Lin, from the Centre on Ageing and Health at Johns Hopkins University in Baltimore, conducted a study in which he eliminated all other factors that may affect cognitive performance, for example socio-economic background and education. He conducted cognitive tests on a group of over 60’s and found that those with a greater hearing loss scored lower in the tests.  The results showed that those with mild hearing loss, 25 decibels, performed to the ability of someone 7 years older.

Studies conducted on mice that were exposed to ‘disco’ noise for 2 hours do show the recovery of hearing but a permanent damage to the auditory nerve.

The studies suggest that, if left undiagnosed and untreated, deafness and other hearing impairments could lead to cognitive problems later in life.