Last reviewed 6 June 2013
Hearing loss relates to a range of conditions affecting a person's ability to hear words and sounds. Some people are born with hearing loss, while in others it may develop as they get older, usually as a result of ageing, illness or injury, or through exposure to loud noise. In this first of a two-part article, Martin Hodgson explains the causes and symptoms of hearing loss.
Action on Hearing Loss, formerly the Royal National Institute for the Deaf, estimates that there are more than 10 million people in the UK with some form of hearing loss. It is highly prevalent in adult social care, particularly among older people, and this makes it especially important that service users, either in care homes or receiving domiciliary care, have access to appropriate care and support.
Causes of hearing loss
The biggest single cause of hearing loss is ageing, often referred to as age-related hearing loss or presbycusis. This occurs when the sensitive hair cells inside the ear gradually become damaged or die, causing hearing to naturally decline from middle age. By the age of 80, most people have some form of hearing loss.
Hearing loss can also be caused or accelerated by exposure to noise. People who work in noisy occupations for a prolonged period may suffer from what is called noise-induced hearing loss, and others may have suffered trauma from extremely intense loud sounds, such as explosions.
Also common are conditions that can block the passage of sounds into the inner ear. Common causes of blockage are ear wax or the build-up of fluid caused by glue ear.
Conductive hearing loss can also be caused by:
ear infections, which cause inflammation and pain
perforated eardrums, where the eardrum becomes damaged
otosclerosis, an abnormal growth of bone in the middle ear.
Other causes of hearing loss can include:
damage to the middle ear, for example by serious infection or head injury
viral or bacterial infections, such as mumps or measles
Ménière's disease, where a person suffers with vertigo and intermittent hearing loss
certain drugs, such as some powerful antibiotics
acoustic neuroma — a benign tumour affecting the auditory nerve
other neurological conditions, such as multiple sclerosis, encephalitis, a stroke, or a brain tumour.
Most hearing problems are progressive, but some people are born with genetic conditions — babies are routinely screened within the first few weeks of birth for such conditions.
Many people who are congenitally deaf will have developed specific linguistic skills based upon some form of sign language, often British Sign Language (BSL). Additionally, deaf people whose first or preferred language is BSL consider themselves part of a community and may describe themselves as Deaf with a capital D to emphasise their identity.
Those with deafblindness have both sight and hearing impairments. They may have been born deaf and later acquired a visual impairment, or may have been born blind and later developed hearing loss. Some may have lost both their sight and hearing later in life.
In addition to hearing loss, tinnitus is another common hearing disorder. Tinnitus is a ringing or hissing noise in the head or ears that can disturb sleep, and is distressing and debilitating for sufferers.
Hearing loss is usually described as mild, moderate, severe or profound, according to the levels of sound that can be heard.
Those with mild hearing loss, often referred to as hard of hearing, cannot hear sounds between 25dB and 39dB. This can make following speech difficult, particularly in noisy situations. People with moderate hearing loss may struggle to hear sounds between 40dB and 69dB and may have difficulty following speech without using a hearing aid of some type.
People who have severe hearing loss may not be able to hear sounds between 70dB and 89dB, and will often need to lip-read or use sign language, even with the use of a hearing aid. Those who are profoundly deaf will typically be unable to hear sounds quieter than 90dB.
Everybody has times when they fail to hear, or mishear, something and sometimes people will have transitory hearing problems. However, more serious hearing difficulties may be indicated by:
having difficulty hearing over the telephone
having difficulty hearing when more than one person in the room is talking or where there is background noise
often having to ask people to repeat themselves
having to turn up the volume of music or the television in order to hear it.
Hearing loss not only means that somebody is hindered in his or her ability to have conversations and to hear things such as the television, radio and music, but he or she can also experience psychological and sociological effects. For instance, a service user with hearing loss may become isolated and withdrawn and find that he or she is unable to mix with others or enjoy doing the things he or she used to do. This can easily lead to feelings of social exclusion, depression and anxiety.
Assessment and diagnosis
Anybody entering a care home or being considered for domiciliary care should have a needs assessment, which includes questions about his or her hearing and ability to communicate. Existing service users should be monitored for signs that might indicate they are having trouble with their hearing. Any needs related to hearing loss should be agreed with the service user and added to his or her care plan.
Service users who experience hearing problems should be encouraged to see their GP who may treat the condition or refer the service user for specialist assessment, usually with an ear, nose and throat specialist or an audiologist.
The GP will want to know how the hearing loss has developed and what sort of problems it causes. A range of tests can also be conducted, usually at an audiology clinic of a local hospital or health centre. These often involve sounds of different tones and volumes played through earphones, or a bone oscillator test to determine the level of hearing.
Service users should be encouraged to see their GP as soon as a problem is detected, as early diagnosis is important. For example, a bacterial infection of the middle ear can be treated with antibiotics, tumours can be removed, blockages of wax can be cleared, and damaged eardrums can be repaired. Hearing loss should not be dismissed as an inevitable part of ageing and all causes should be thoroughly investigated. Careful checks should be made for any service user with communication difficulty, to ensure that the correct source of the problem is identified.
Unfortunately, for people with many forms of sensorineural hearing loss, such as age-related hearing loss, the condition is permanent. However, a range of adaptations or aids may be available to help those affected live with the condition and improve their quality of life. Hearing aids are perhaps the most common.