Professional Reference articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Synonyms: age-related hearing loss
Presbyacusis is a progressive, usually bilateral, sensorineural hearing loss that occurs in older people as they age. It is a multifactorial process determined by a combination of genetic and environmental factors.
It can range from bothersome to severely disabling in its effects. In moderate-to-severe cases it can cause the older person to become isolated and depressed, and may significantly worsen age-related disability/cognitive impairment and dementia.
It is eminently correctable using rehabilitative measures and its successful treatment can vastly improve quality of life for the older patient. However, the majority of those who would benefit from hearing aids do not present for assessment or use them when issued.Screening by elderly care specialists and primary care physicians, with referral for appropriate therapy, can make a positive and tangible difference to the lives of older people.
You may find the separate articles Deafness in Adults and Dealing with Hearing-impaired Patients useful. These contain information on examination and managing a consultation with a deaf person, and an overview of treatment options. You may also find the separate article Tinnitus relevant.
A number of central and peripheral auditory factors contribute to the development of presbyacusis. These include:
- Reduction in auditory sensitivity to sound.
- Deterioration in understanding of speech, particularly perception in noisy environments.
- Reduced central auditory processing.
Central presbyacusis is thought to be a part of a multifactorial process, in which the importance of different factors varies between individuals, rather than an entity in its own right.Causation is multifactorial, involving potentially a number of intrinsic and environmental factors.
Intrinsic factors include:
- Neuronal loss.
- Loss of cochlear outer hair cells.
- Atrophy of the highly vascular stria in the lateral cochlear wall.
- Oxidative stress causing DNA mutation and damage.
- Metabolic and systemic disease including hypertension and diabetes.
Extrinsic factors include:
- Ototoxic medication.
- Noise exposure - eg, exposure to industrial/urban/armament noise without ear protection.
- Ototoxic medication - eg, aminoglycosides, cisplatin, loop diuretics, non-steroidal anti-inflammatory drugs (NSAIDs).
- Genetic susceptibility/family history.
- High body mass index.
- Diabetes mellitus.
- Vascular disease.
- Alcohol. (Inconsistent study results - occasional alcohol may be protective, whereas excess alcohol may contribute.)
- Low socio-economic level.
It is unclear whether these factors act in specific, pathological ways or whether they accelerate an underlying process.
The UK charity Action on Hearing Loss - previously the Royal National Institute for Deaf People (RNID) - estimates there are currently more than 10 million people in the UK with some type of hearing loss, or one in six of the population. The vast majority of these have developed hearing loss over time.
70% of those over 70 years of age have some degree of hearing loss, and 40% of those over 50. Around 2 million people in the UK have hearing aids, but only 1.4 million use them regularly. It is estimated that at least 4 million more people would benefit from hearing aids.
Presbyacusis is more common in men than in women.
Problems are often first noted in noisy environments; there is usually a slow, insidious onset of symptoms with gradual progression. However, some people may feel their hearing has suddenly worsened due to crossing a "threshold" where the symptoms become noticeable. (It is also known that the rate of hearing decline is a highly variable, non-linear process.)
The ability to understand speech is often the earliest symptom as high-frequency hearing loss predominates. It may be the patient's friends/relatives who note the problem, rather than the patient. Discrimination of the voiceless consonants (t, p, k, f, s and ch) becomes difficult as the condition progresses (patients may complain of others mumbling). Patients complain that they cannot understand what is being said rather than of an inability to hear. Words like "mash", "math" and "map" become indistinguishable. Patients can usually manage a one-to-one conversation but struggle when there is more than one speaker and when there is background noise.
When assessing elderly patients with depression or cognitive impairment, consider hearing loss as a cause of the symptoms. Tinnitus may be a feature of presbyacusis when the hearing impairment becomes marked. Ask about tinnitus directly, as it can be very disturbing and disabling.
There are no definitive signs of presbyacusis. Auroscopy may reveal wax (cerumen) accumulation. Olive oil or 10% sodium bicarbonate drops will help to dissolve this and may improve symptoms, when reassessment can take place. Opacification of the tympanic membrane is a normal feature of ageing and does not affect the acoustic efficiency of the ear.
Presbyacusis is a diagnosis of exclusion and should not be made as a blanket diagnosis in the elderly person with hearing loss until other possible causes have been considered and excluded/thought unlikely. Consider:
- Wax (cerumen) impaction.
- Foreign body.
- Infection: otitis externa or otitis media (acute or chronic suppurative).
- Benign tumours of the middle ear.
- Noise-induced hearing loss.
- Perforated tympanic membrane.
- Acoustic neuroma.
- Infection/tumours of the petrous temporal bone.
- Autoimmune disease of the middle ear.
- Ototoxic medication.
Asymmetrical sensorineural hearing loss or rapid onset should raise suspicion of another cause.
Pure tone audiometry confirms the diagnosis. Hearing is measured over a range of pure tones in each ear. Frequencies vary from low pitches (250 Hz) to high pitches (8,000 Hz). It measures the threshold for air and bone conduction and can determine whether it is due to conductive or sensorineural loss, or mixed. Lack of a significant difference between the air and bone conduction thresholds implies that the hearing loss is sensorineural in nature. Hearing loss increases in severity as the frequency increases.
Further investigation such as neuro-imaging is not required unless there are clinical reasons to suspect an underlying pathology - eg, unilateral or significantly asymmetric hearing loss or troublesome tinnitus out of keeping with the severity of hearing loss on the audiogram. Tests for diabetes, renal impairment, hypertension or dyslipidaemia are worthwhile in individuals who have not been checked recently for these problems.
It is a good idea to conduct screening for presbyacusis in patients aged over 60. Asking "Do you have a hearing problem?" on new-patient questionnaires or during health checks for older people is a very cost-effective and sensitive instrument to screen for this condition. However, benefits of screening are reduced because many people do not then wish to have audiometry, and if hearing loss is established many decline to use hearing aids.
- Communication, courtesy and environmental noise manipulation - both speaker and listener should work at improving communication. Speakers should be face-to-face, reduce competing sounds where possible, and should speak in a clear and unhurried manner. Listeners should repeat what was heard to allow misunderstandings to be corrected. In addition, it may help to give out written material or to give explanation to family and friends.
- Reassurance and education - patients often find it very reassuring to know that they will not go completely deaf. It has been shown that proactive communication education programmes have an important role to play in the management of these patients. This may be as an adjunct to - or even replace - more traditional interventions (eg, hearing aid fitting - see below).[13, 14]
- Assistive listening devices - these include flashing light alarms (eg, for doorbell or smoke alarm), vibrating alarm clocks, amplified telephones, teleconnectors for hearing aids/phones, frequency-modulation transmitters (an FM microphone/transmitter and receiver) and other devices. They can make a great difference to people's lives. Hearing dogs are also used. More information is available on the Action for Hearing Loss website.
- Speech reading - use of facial visual cues and study of lip movements aid understanding of speech. Formal training in these skills may be difficult to come by.
80% of people aged 55-74 who would benefit from a hearing aid do not use one. Many who are given a hearing aid do not use it. Reasons for this include:
- Lack of sufficient benefit.
- Difficulty with noisy situations or backgrounds.
- Lack of dexterity required to use device.
- Dislike of appearance of device.
- Financial considerations (less so in the UK where hearing aids are available free on the NHS).
These findings suggest that increasing support, information and counselling given with hearing aids would improve their usage. There is evidence that when used correctly, hearing aids improve quality of life.
Most NHS hearing aids are now digital, replacing analogue hearing aids. There are ongoing advances in directional microphones and noise-suppression circuitry which continue to improve performance. Hearing aids are available both on the NHS and privately; privately sold aids are not necessarily better than those obtained on the NHS. For patients considering private treatment, direct them to websites such as those of the Action on Hearing Loss and ENT UK, where there is a wealth of information about hearing aids.
Hearing aids have problems about which patients should be counselled: normal hearing is not restored, it takes time to learn to use and adapt to one. Several months may be required to gradually build up the time for which the device is used, whilst getting used to the different sounds produced. With time and support and explanation from the audiology clinic, however, they can be extremely helpful.
The main types of hearing aids are:
- Behind-the-ear hearing aid - most NHS hearing aids.
- In-the-ear hearing aid - suitable only for milder degrees of hearing loss. Less visible than behind-the-ear devices.
- In-the-canal hearing aid - fits right inside the ear canal, and is therefore the most cosmetically acceptable; however, it is only effective for mild hearing loss.
- Bone-anchored hearing aid: for conductive deafness, but also used for those with ear malformations who are unable to wear conventional hearing aids. May be bulky, obvious and uncomfortable.
These consist of several parts, including a wire electrode surgically inserted into the cochlea, a microphone behind the ear, a receiver/stimulator implanted under the skin behind the ear, and a cable to a processor worn on a belt or in a pocket. Cochlear implants are approved by the National Institute for Health and Care Excellence (NICE) for any patient, regardless of age, who has bilateral severe hearing loss not materially improved by hearing aids.The older patient will probably do well due to good language skills and relatively short duration of deafness. Good outcomes have been reported for cochlear implants in people with presbyacusis.[20, 21]
Electric acoustic stimulation is the combined use of a hearing aid and cochlear implant. It involves preserving existing residual acoustic hearing (low-frequency) in an ear, with the addition of a cochlear implant for the missing high frequencies to produce speech understanding.[22, 23]
Active middle-ear implants:
- This is a prosthesis implanted in the middle ear, which mechanically vibrates the middle-ear structures.
- It can be useful in patients with mild-to-severe sensorineural hearing loss, who are unable to wear conventional hearing aids.
- These are still undergoing evaluation, evidence suggests they have similar efficacy to external hearing aids.[25, 26]
Untreated presbyacusis has a significant detrimental effect on quality of life. It can contribute to social isolation, loneliness, dependence, loss of self-esteem and depression. It may cause or worsen cognitive impairment and dementia.
Hearing loss has been found to be associated with an increased mortality risk.
The stereotypical image of old age as an inevitable decline into severe deafness is not warranted. Early identification and management of presbyacusis can significantly improve the lives of older people and help to change this picture.
Some sensory presbyacusis is inevitable but avoiding noise exposure and using ear protection in noisy environments will prevent some progressive damage. Younger patients should be informed of the danger of repeated and prolonged noise exposure in clubs/at music events. Good diet, general health and fitness can reduce cardiovascular contribution to hearing loss. The role of anti-oxidants in the management and prevention of hearing loss is still being investigated.
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Further reading & references
- Rabinowitz P, Taiwo O, Sircar K, et al; Physician hearing loss. Am J Otolaryngol. 2006 Jan-Feb 27(1):18-23.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.