Age related hearing loss and the connection with dementia.
It is estimated that in the UK, 1 in 10 individuals exhibit common ‘traits’ of hearing loss. Characteristically, these ‘tell tale’ signs manifest in various perceived difficulties – the notion that people ‘mumble’ or speak indistinctly, the increasing need for people to repeat themselves and a growing awareness that physical sound sources such as the phone, TV and radio are, seemingly, not as loud as they used to be!
The biggest cause of hearing loss in the UK and certainly in most parts of the Western World is linked to age-related hearing loss. The charity, Action On Hearing Loss estimates that 70% of the over 70’s age group display some form of hearing loss. As the population is projected to live longer, it is only logical to surmise that this trend will only continue.
How we Hear
The ability to hear is derived from capturing sound vibration and interpreting it into a value which we recognize as ‘sound’. Whilst the outer and middle ear play a vital role in chaneling this information, it is the inner ear, or more specifically thousands of tiny hair cells (cilia) in the cochlea of the inner ear, which convert the signal into the electrical impulses understood by the brain.
As the body matures, the hair cells responsible for capturing and transmitting sound vibration, start to wither and deteriorate, leading to resultant hearing difficulties. Whilst the rate of hair cell decline varies between people of a similar age group, other extraneous factors may hasten the rate of decline. Exposure to harmful noise, both in terms of intensity and length of exposure, long term use of certain otytoxic drugs and even hereditary links can all play a part.
Lamentably, damage or depletion of the hair cells is irreversible. As the body is unable to regrow or regenerate new hair cells associated hearing loss, if not curable can at least be ‘managed’. Today, a number of research centres are looking at stem cell regeneration as a corrective measure, whilst his would theoretically ‘cure’ cochlea hearing loss it is a proposition which is still many years from being realized.
Unmanaged Hearing Loss
Although age-related hearing loss is not curable it can and should be managed. Evidence suggests that unmanaged hearing loss will not only impact on one’s acoustic quality of life, but can have far reaching mental health implications resulting in psychological behavioural changes and even depression.
Furthermore, over the last two years it has been widely reported that cognitive decline, as a result of living in a muted world, may actually advance the progression of dementia.
Hearing loss, rarely leads to total deafness. Some sounds and certain frequencies, can be heard without amplification but the impact on the high frequencies and consequent loss of clarity make ‘listening’ an onerous task. As effective communication becomes more difficult many recoil from social interaction altogether.
Researchers believe that individuals with unmanaged hearing loss and correspondingly, reduced auditory stimulation are far more likely to develop dementia. Whilst hearing loss has not been cited as the cause of dementia there is a strong trend to suggest that it certainly has a role in its propagation.
Managing Hearing Loss
It is fortunate that in the UK, access to hearing provision, or some form or intervention, is readily available. Hearing tests are often the first step and can be carried out at a local hearing centre (often free) or via a local NHS trust (GP referral is required). The hearing test will not only assess the type and degree of impairment but will help to consolidate management strategies pertaining to an individual’s needs.
For age-related losses, the standard recommendation is for some form of amplification, typically hearing aids. Whilst hearing aids will not restore ‘normal’ hearing they can be programmed to re-dress specific, diminished frequencies and restore the balance of loudness perception. Other solutions offered may be in the form of situation-specific aids, such as amplified phone (home or mobile), alerting aids (bells and alarms) and even dedicated ‘listeners’ for watching TV.
If you have any concerns about your hearing or even the hearing of someone you care for, it is worth consulting with your GP and taking the first step towards hearing rehabilitation and take the free on line hearing test at Hearing Direct .
This article was written by Melanie Lewis, a trained hearing aid audiologist at Hearing Direct.
