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Most children have occasional fluid behind the eardrum (in the ‘middle ear’) during infancy. This fluid, which can occur in either or both ears, typically causes a mild hearing loss, impairing listening. The fluid usually clears up after a few weeks. If it reoccurs persistently, as it does in about 15% of cases, the child has “glue ear”, also called otitis media with effusion (OME). OME usually occurs on and off until the child is 4 – 5 years old, after which in all but a few cases it gradually declines. The fluid that fills the middle ear comes from the cells that line the middle ear cavity. This happens, often following colds or allergies, when the eustachian tube, joining the middle ear to the back of the mouth, remains closed for long periods. The normal opening of the eustachian tube, equalising pressure on the two sides of the eardrum, is what causes your ears to ‘pop’. A common treatment for OME is to put
grommets in the eardrum. These act like an artificial eustachian tube.
OME can cause problems in language development, behaviour and schooling, especially in children who are socially deprived. When fluid causes impaired hearing, parents and other carers should speak directly to the child, ensuring that they have the child’s attention. If the hearing problems persist over more than a few weeks, or the child also has pain or fever (suggestive of an acute infection), he/she should be taken to the family doctor. Treatment options are considered elsewhere on this
website.
A child with persistent fluid behind the eardrum has “glue ear”, also called “otitis media with effusion” (OME –see question
What is glue ear?). In many cases the condition clears up without treatment. However, in severe cases, the child may be referred to the local hospital ear, nose and throat (ENT) department where grommet insertion may be recommended if the glue ear persists. Grommets are tiny bobbin-like ventilation tubes inserted in the eardrums, to keep the fluid away. They do this by making it easier for any new fluid to drain away into the throat and making it difficult for bacteria to grow and cause fluid secretion from the lining of the middle ear. Grommets produce good hearing for as long as the tubes remain in place, but when they fall out (usually in 6-12 months) the problem may return. In those children, repeat operations to re-insert tubes are sometimes performed, but a hearing aid is now commonly offered after about 3 insertions.
In the past, very many children diagnosed with OME received grommets, but the number has reduced steeply in the last 10 years. This has been due to growing realisation by doctors that the benefit was not great enough in many cases to justify giving a general anaesthetic, especially in a condition that mostly corrects itself. However, some children that have been carefully observed and found to have OME and poor hearing for more than 3 months can benefit considerably from grommets. When adenoids are taken out at the same time, the improvement in hearing is slightly greater, but lasts much longer and underlying physical health also benefits.
Hearing impairment in adults
The National Study of Hearing, which was carried out by the MRC Institute of Hearing Research, and reported by Davis in 1995, shows that 16% (approximately 1 in 6) adults have a significant hearing impairment in both ears. Hearing impairment increases greatly with age. Whilst only 2% adults in the age range 18-30 years have a significant hearing impairment, this rises to 60% in the age range 71-80 years. There are differing amounts of hearing impairment, these are described by Audiologists as mild, moderate, severe or profound. Less than 1% of adults have a profound hearing impairment in both ears.
Further details on the numbers of people (prevalence) with hearing impairment in the adult GB population is available by following
this link.
Hearing impairment in children
Many children have temporary hearing impairments that are mostly caused by
glue ear (Otitis media with effusion). About 1 in 1000 babies are born in the UK each year with at least a moderate hearing impairment in both ears (bilateral). This translates to about 900 babies born each year with a bilateral hearing impairment. We also know that some children will develop or acquire hearing impairment in early childhood so the figure increases up to at least 1.65 in 1000 by 9 years of age. It is possible to obtain more detailed information on childhood hearing impairment, including risk factors for and causes of hearing impairment, by following
this link.
Cochlear implants comprise several parts. One part is a set of tiny wire electrodes that form rings around a thin plastic tube about the size of a pencil lead. These electrodes are placed by a surgeon in the inner ear (cross link to inner ear description in ‘causes and treatments of hearing loss’ section). The aim is to by-pass parts of the ear that do not work and to stimulate the nerve of hearing directly with electrical signals. The other parts of a cochlear implant are a microphone and a microchip ‘speech processor’ which are worn behind the ear like an ordinary hearing aid. These parts are connected to a transmitter coil which is worn on the side of the head. The transmitter coil sends signals to the electrodes.
Candidates for cochlear implants are people who are profoundly deaf and who do not benefit from ordinary hearing aids. One group of candidates are people, both adults and children, who lost their hearing after learning spoken language. Most of these people find that an implant helps them to monitor the sound of their own voice, which gives them more confidence when speaking. The sensations generated by an implant combine well with lipreading, and allow users to lipread more accurately, more fluently, and with less effort. Many users can understand some speech without lipreading, particularly if the talker is a familiar person and if there is no background noise. Some users of implants can understand speech when using the telephone.
The other group of candidates are children who were born profoundly deaf. Implantation can help such children to acquire spoken language. The benefits of implantation seem to be greater the younger the age at which children in this group receive implants. It is now common in the UK for some profoundly deaf children to receive implants as young as 1-2 years of age.
About 450 cochlear implants are provided annually in the UK. To date, about 5,000 have been provided in the UK and 50,000 internationally.
Everybody who has a hearing problem should have their hearing assessed. This can be arranged through your family doctor. If there is a hearing loss then a hearing aid is often the best form of treatment. A hearing aid should have the best possible combination of features. This will often mean getting a digital hearing aid, not simply because it is ‘digital’, but because digital aids usually have more features. However, some people will be best with non-digital (‘analogue’) hearing aids depending on their individual needs. All hearing aids perform best in quiet environments, but may be of less value in noisy situations. Overall, however, hearing aids improve people’s quality of life. The best thing is to have a thorough assessment and discussion with an Audiologist. Then the features needed for your own, individual hearing aid can be determined. The following web links give more specific information about hearing aids and hearing aid services in the National Health Service.
Auditory processing disorder (APD) describes a difficulty listening to sounds even though the ear seems to be working normally. APD may be suspected when there is particular difficulty listening in noisy situations (e.g. children in classrooms). It often occurs with and may contribute to language problems (e.g. dyslexia), but you can have APD without a language problem and vice versa. A sizeable number (perhaps 20%) of both children and adults referred to hospital ear, nose and throat departments pass the usual tests (including hearing very quiet tones - the ‘audiogram’), but still complain of listening difficulties. These people may have APD (sometimes called ‘obscure auditory dysfunction’ – OAD – or King-Kopetzky syndrome).
At the MRC Institute of Hearing Research we are intensively researching both the
diagnosis and treatment of APD. In addition, the British Society of Audiology has recently started a
special interest group to help formulate national policy on APD. We expect both these efforts to make substantial improvements in our understanding of APD in the coming years. In the meantime, the best advice we can offer if APD is suspected is, first, to arrange a full assessment of hearing through your family doctor. If APD is diagnosed, then improved (i.e. less noisy) listening conditions can help a lot (e.g. a carpet in a classroom), as can facing the speaker, ensuring that the speaker has the listener’s attention. There is some evidence that assisted listening devices and computer-based auditory training programmes may also help.
Exposure to loud noise is the most common preventable cause of acquired hearing loss, known as noise induced hearing loss (NIHL). (
www.entnet.org/healthinfo/hearing/noise_hearing.cfm) This results from damage to the sensory hair cells within the inner ear. (
http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eari.html#c2) Sometimes excessive noise exposure can also result in ringing or buzzing noises in the ears or head, known as
tinnitus. Noise damage can be prevented by wearing hearing protection such as earmuffs or earplugs. The Noise at Work Regulations that aim to protect hearing of employees working in noisy environments require that employees wear hearing protection and these regulations are due to become more strict in 2006, to reduce NIHL further. (
www.hse.gov.uk/lau/lacs/59-3.htm and
www.noiseatwork.info) Research has shown that noise exposure due to social activities such as nightclubbing can also damage hearing. The RNID have recently launched a campaign to increase awareness of young people to the risks of noise damage due to loud music played in nightclubs and suggest that clubbers take regular breaks from the dance floor and stand away from loudspeakers. (
www.dontlosethemusic.com)
Tinnitus is any sound which people hear in one ear, both ears or in the head that isn’t generated by an external sound source. Tinnitus is described variously as ringing, whistling, buzzing and humming. Tinnitus occurs in people of all ages. It is a symptom that can have many different and complex causes. Most people have experienced brief periods of tinnitus at some time in their life, often after exposure to loud noise. Tinnitus can sometimes be linked to hearing loss, ear or head injuries, some diseases of the ear (e.g. infections), emotional stress, or the side effects of medication. Tinnitus can be associated with one or more of these things, but some people who don’t have a hearing loss or any other clear cause can experience tinnitus.
At least 1 in 3 adults report that they experience some kind of tinnitus, and about 1 in 10 experience tinnitus that is both spontaneous (i.e. not always occurring after loud sounds) and lasts for more than 5 minutes.
There is no single treatment for all forms of tinnitus. Occasionally, it is possible to treat the underlying condition that may be causing tinnitus. There are also a number of ways to manage your tinnitus so that you become less aware of the sound. These treatments are often not a quick fix, but may become effective gradually over the months. Different audiology departments may offer slightly different methods, but the main options are generally hearing aids, sound generators that hide or distract from the tinnitus, relaxation therapy and counselling. Some tinnitus clinics use tinnitus-retraining therapy or cognitive behavioural therapy. In addition, local self-help groups can provide support and understanding that many find enormously beneficial.
If you are worried about your tinnitus you should visit your family doctor. They may refer you to your local hospital ear, nose and throat (ENT) department or tinnitus clinic or audiology department. The RNID Tinnitus Helpline (Tel: 0808-808-6666) also offers useful information and advice to people with tinnitus.
1. The RNID is a charity that represents deaf and hard of hearing people in the UK (
www.rnid.org.uk).
2. The British Tinnitus Association disseminates a lot of useful information about tinnitus (
www.tinnitus.org.uk).
Most people as they get older experience some degree of hearing loss. The causes include environmental factors (e.g. noise), diseases (e.g. diabetes), medicines (e.g. some antibiotics), and other unknown factors produced by ageing. As with many diseases, healthy lifestyles may help to minimise hearing losses.
Most age-related hearing losses are due to problems in the cochlea, the snail-shaped structure in the inner ear, where sounds are converted into nerve signals. They are not treatable by surgery or medicines. Providing amplified sound via a hearing aid or (in extreme cases) a cochlear implant is the treatment of choice. Today’s hearing aids give benefit to very many people in the UK, and anyone experiencing hearing difficulties is advised to consult their family Doctor with a view to trying hearing aids.
The single biggest complaint people make about their hearing is that they have difficulty in noisy places such as classrooms, parties, bars and railway stations. It is perfectly normal to have at least some problem hearing speech in these circumstances because the noise physically ‘masks’ the speech. This is the same effect you would find if you detuned your radio or TV and tried to make yourself heard over the background noise. However, human hearing has developed various special abilities to help deal with these problems. One is called ‘grouping’, a brain process where similar sounds are heard as belonging together. Thus, a particular voice can be heard against other voices because it has certain properties (e.g. pitch of voice, accent) that are continuous over time. Binaural hearing – combining the information from the two ears – helps to separate sounds that come from different directions. Somebody talking to you from the front can then be separated from someone talking to the side. Lip reading (now correctly called ‘speechreading’) also helps, even in normally hearing people.
These and other processes thus improve our ability to hear in difficult circumstances. But they can go wrong. People who have a hearing loss in the ear almost always have an additional problem hearing in noise. This may sound surprising, as you would expect the hearing loss to reduce the level of both the ‘target’ sound AND the noise. But cochlear hearing losses also impair other aspects of hearing, including the ability to separate sounds of similar pitch and sounds occurring close together in time. Other
problems with ‘central auditory processing’ can contribute to poor speech-in-noise hearing. These include binaural hearing and grouping. It is likely that both sources – ear and brain – contribute to the often reported difficulty of many elderly people to hear well, especially in noise. Current hearing aids fitted in modernised NHS hearing services provide more benefit to people than earlier hearing aids did in this situation, and research continues in this area.
