Effects of Loud Noise or Sound
Loud noise or sound causes loss of hearing acuity / partial deafness. This is permanent and cannot be cured. The effect on those who have suffered a substantial amount of hearing loss is dramatic. They find it difficult to understand what other people are saying. Others have to speak loudly or shout to be heard, and this causes frustration, embarrassment and annoyance. It means that the TV has to be turned up loud and this can cause annoyance and arguments with others in the family, plus annoyance to neighbours.
It also spoils enjoyment of music.
Loud noise also causes permanent tinnitus, which is a ringing, buzzing or rushing sound in the ears that is always there and never goes away. Many people find this unpleasant and annoying. Tinnitus can make it difficult for people to get to sleep because it is most noticeable in a quiet environment. There is no cure for hearing loss or tinnitus caused by exposure to loud noise / sound. Hearing aids can help, but they do not normally provide the full quality of hearing that was enjoyed prior to damage by loud noise. Also, people find hearing aids a nuisance to wear. Many people are embarrassed about wearing them – some are too embarrassed to wear them and struggle on without them.
Common sources of loud noise include discos, concerts, live bands and some other forms of amplified music or speech. For people who work in factories, industrial machines are another major cause of loud noise.
Noise can also cause nuisance. This occurs at much lower sound levels than noise that causes hearing damage. It can keep people awake at night, disturb concentration, spoil enjoyment of music, television and ruin the peace and quiet. Very common causes of noise nuisance include dogs barking, neighbours’ music, parties, loud speech and laughter, and fans or air conditioning units at offices, shops and industrial factories. There is a section on noise nuisance at the bottom of this page.
Most research on hearing damage risks has been carried out for noise at work. Based on this research, the Health and Safety Executive have produced data showing the hearing loss risk at various noise levels. This has been used to set the noise limits contained in the Control of Noise at Work regulations. These regulations require that noise levels are reduced and ear protectors worn wherever workers’ noise exposures equal or exceed 85 dBA (dBA means decibels adjusted to mimic the human ear’s hearing acuity at different frequencies / pitches). Because a substantial proportion of people are likely to suffer hearing damage when the noise is below 85 dBA, the regulations also contain a lower action level of 80 dBA. At and above 80 dBA, employers must give workers hearing protectors and they must train workers on the hearing damage risks and how to minimise them. They must also carry out a noise assessment that measures workers’ noise exposures.
Typical average sound levels at a disco in a night club are 105 dBA, but they can reach 110 dBA or more. The sound from live bands at pop concerts can exceed 110 dBA. iPods / MP3 players can produce sound levels of 100 dBA or more. These sound levels are all considerably higher than the 85 dBA level at which, by law, ear protectors (ear plugs or ear muffs) must be worn and noise levels must be reduced for people at work.
Using 105 dBA as an example, this is so high that a total of only 24 minutes’ exposure to this sound level in a week would cause the person’s noise exposure to equal the weekly 85 dBA upper limit contained in the Control of Noise at Work regulations. Exposure to 105 dBA (the typical sound level at a disco) for just 24 minutes in total during a week produces exactly the same noise dose as being exposed to 85 dBA for 40 hours in a week (this is the legal limit for noise at work). If someone spends 4 hours at a disco, one night a week, their weekly exposure would be 10 times the legal noise limit for those at work.
This example shows that the hearing damage risk at discos and live bands, etc are extremely high even though the exposure time is quite short. A study by Royal National Institute for the Deaf (RNID) found that up to three quarters of 18 – 30 year olds have suffered hearing problems as a direct result of exposure to high sound levels at discos and live bands.
At 100 dBA, exposure for just 15 minutes’ per day for 5 days a week, or for a total of about 1 hours a week, would produce the same noise dose as the 85 dBA noise at work upper limit. This means that listening to an iPod / MP3 player at or near maximum volume (which is typically about 100 dBA) can cause permanent hearing loss after a very short time. Hearing loss can also occur at lower sound levels when listening to an iPod for longer periods.
The risk of hearing loss varies from person to person. Some people are more susceptible than others and suffer hearing loss at lower noise levels than others. There is no way of telling in advance who is more susceptible than the average person. The hearing loss risk at different noise levels is shown in the following data published by the Health and Safety Executive:
Estimated Hearing Loss of 30 dB after 40 years’ exposure (Source: HSE)
|Noise Exposure (dBA)
|Percent of people
Interpolating the data gives the following approximate figures for the action levels in the Control of Noise at Work regulations:-
85 dBA : 26% of people
80 dBA : 15% of people
You can see a summary of the regulations by clicking on Control of Noise at Work Regulations
Our ears provide us with a warning sign when sound is too loud. Go somewhere quiet after being exposed to high noise levels. If your ears ring, buzz or hiss, it probably means the sound was loud enough to cause some permanent hearing loss. The louder the ringing, buzzing or hissing, and the longer it lasts, the greater the risk that your hearing has been damaged.
If people have ringing, buzzing of hissing (this is called tinnitus) all the time even when they have not been exposed to loud noise, this usually means that they have suffered hearing damage and loss of hearing acuity. In this case, the ringing, buzzing or hissing usually sounds louder for a while after being exposed to sound that is too loud (although this may depend on how bad the tinnitus is). So it can still serve as a warning sign. However, for some people who have ringing, buzzing or hissing in their ears all the time, there might be another cause than hearing loss. Some other medical conditions or prescriptions can cause this – consult a doctor.
Tinnitus (ringing, buzzing or hissing in the ears) that occurs for only a short time after exposure to high noise levels is an early warning sign that your hearing is at risk and you may have suffered some permanent loss of hearing acuity. The only other signs are ones that indicate substantial or severe hearing loss has occurred. One is tinnitus that is constantly present (although there can be other causes – see above). Another is difficulty in understanding speech. Usually this first becomes apparent when listening in a noisy background, where lots of people are speaking or there is background music. As the severity of the hearing loss increases, it shows up in other situations. One common example is other members of the family complaining frequently that the television is too loud. If any of these occur, ask your doctor for a hearing test and advice.
In the early stages of hearing damage, people usually do not notice that they have suffered hearing loss. At first, the brain manages to fill in missing information. By the time people realise they have suffered hearing damage, they have usually suffered a large amount of hearing loss. The lost hearing can never be replaced. It is gone forever.
From about the age of 18, age-related hearing loss starts to occur. At first the effect is very small, but it increases at a much faster rate as we get older. This adds to any hearing loss caused by exposure to loud noise. Usually, it is this combination that causes people to start experiencing difficulties in understanding speech and spoiling enjoyment of music. This is the reason that people usually do not realise they have suffered hearing damage until long after they were exposed to loud sound. It is often only once a substantial additional hearing loss due to ageing occurs that they start noticing the effect.
Exposure to loud sound can dramatically accelerate the ageing effect. It is predicted that in future many people who go to discos and live music events and / or use iPods will have to wear hearing aids once they reach their forties (or sooner) instead of when they are in their seventies.
People who have suffered some hearing loss have less hearing left to lose. So they need to take extra care to avoid being exposed to loud sound at all times in the future. Otherwise the hearing loss and the difficulty in understanding other people speaking will only get worse.
How to Reduce the Hearing Damage Risk
It is often stated that you can reduce your daily noise dose by minimising the time you are exposed to loud sound. This is true. But it takes a very large reduction in time to produce a substantial effect. If you halve the time you are exposed to loud sound during a day, this reduces your daily noise exposure (dose) by only 3 decibels. Reducing it by three quarters lowers the daily exposure by 6 decibels. You would need to reduce the exposure time by nine tenths (i.e. 90%) to lower your daily exposure by 10 decibels.
It is much more effective to reduce the sound level. For example, the sound from an iPod can be reduced by 10 – 20 decibels, or more, simply by turning down the volume control knob. Suggestions and information on reducing noise levels are given below for common sources of sound that are loud enough to cause hearing loss.
Discos, live bands, amplified music and speech
When the sound is loud at discos, live bands, or anywhere else where there is amplified sound, you could ask for the sound level to be turned down. Ask the DJ, and if that fails, ask the manager. Point out that they could be sued if they cause people’s hearing to be damaged by exposing them to loud sound.
However based on our past experience, if they turn the sound down at all, it is usually only by a small amount, and it is normally turned back up again very soon afterwards. People that operate discos, live bands, shows and amplified sound do not seem at all concerned that their customers are being deafened. It will probably take a new law to force operators to reduce the sound to a safe level, or someone suing them for hearing damage and winning thousands of pounds in damages.
You could try lobbying the Government or the European Union to bring in a law that limits all amplified sound to a safe level – which probably means 80 dBA or less.
In the meantime, you should wear ear protectors whenever exposed to loud sound. The options are ear muffs, or ear plugs. Ear muffs fully enclose the ear and are very easy to put on. Ear plugs fit inside the ear canal, which means they are much less visible. However, it is much more difficult to fit them correctly. If they are not fitted correctly, they can provide considerably less noise reduction than they should. It is very common to see ear plugs that have not been inserted properly. In many cases, they have been inserted so badly that they provide little noise reduction. Details are given below on how to fit ear protectors correctly.
iPods / MP3 Players
It is very easy to reduce the risk of hearing damage caused by iPods / MP3 players. Simply turn down the sound volume control knob. The difficulty is knowing what volume or sound level is safe. Some iPod / MP3 players have a sound level limiter or allow you to enter a code that locks or limits the maximum volume. For some types of ipods, you can download software from Apple that limits the sound level. This prevents the sound level exceeding the maximum level that you set in the software. You could try using these where fitted.
ipods / MP3 players are usually sold with standard earphones that fit loosely in the ears. If wearing these, make sure that the player is never so loud that people around you can hear your music or that you can’t hear other sounds around you, like people speaking. If you use the type of earphones that have a rubber sleeve that seals the earphones to your ears, or headphones that fully enclose your ears, this guidance does not apply. This is because the seals prevent music escaping from the earphones so easily – it also stops external sounds getting into your ears so easily.
Avoid increasing the sound level after you have been listening for a while. We get used to sound after a short time. This means that it may not appear loud, even though it is. You can check by removing your earphones for a short time, then putting them back on. This will give you a better idea of how loud the sound is. This assumes you are in a relatively quiet area – it would not work if you were somewhere noisy like near industrial machines in a factory!
Do not increase the sound level to block out external noise. If external noise is a problem, you could try noise cancelling headphones or headphones with rubber seals. However, you should be extra careful that the iPod sound level is not too loud, and that you can still hear people speaking nearby. Also, using different earphones than those supplied with the iPod can alter the sound level considerably. So if you have set a maximum limit, this might need to be altered if you use different earphones.
Set the volume loud enough to hear clearly in quiet surroundings, and no louder. Try to keep the volume low enough that you can carry on a conversation with people nearby.
Immediately after finishing using your iPod, go somewhere quiet. If your ears are ringing, buzzing or hissing, it usually means the sound was too loud and could have caused some loss of hearing acuity. See ‘warning signs’ above for more details.
Industrial Noise Control
There are several techniques available for reducing the noise from industrial machines and fans. Details of all these are given in our Guide – how to reduce work-place noise: 6 steps.
Acoustic enclosures are a common method used to reduce industrial noise in a factory. They provide a large noise reduction. However their cost is very high. Also, enclosures restrict access and visibility, making it more difficult for workers to operate machines and this can impair productivity. It can also increase the time needed to carry out maintenance and breakdown repairs. An enclosure can also make it much more difficult to move raw material in and finished product out.
An alternative is to use a solution that reduces the machine noise at source using engineering noise reduction techniques and / or advanced technology. The main benefit is much lower cost than acoustic enclosures. The savings often amount to thousands of pounds. Because this type of solution involves very small machine modifications, it avoids all access and visibility restrictions. So there is no interference or restriction on machine operation, maintenance, or movement of materials and finished products into and out of the machine. For more details and some examples of this type of solution for reducing factory noise, click on work-place noise reduction.
It would be wise to wear good quality ear muffs or ear plugs whenever operating loud machinery at home. Examples include electric drills and saws, hedge cutters, lawn mowers, hammers, etc.
How to Fit Ear Protectors Correctly
It is very common for ear plugs to be inserted incorrectly such that they provide little reduction in noise exposure. To insert an ear plug, pull the top of the ear upwards to straighten the ear canal, then push the plug in fully until it makes a very good seal.
If using foam plugs, it is essential to first roll the plug into a thin cylinder between the finger and thumb. Then insert the plug while pulling the top of the ear upwards. Hold the ear plug in place with your forefinger long enough for the foam to expand fully and seal the ear canal. Repeat for the other plug.
Note how the noise changes on inserting ear plugs. If the noise does not appear considerably quieter and ‘muffled’, then one or both of the ear plugs have been fitted incorrectly and must be adjusted by pushing them further in, or by removing and re-inserting them. It is common for ear plugs to become slightly dislodged or loosen over time, due to jaw movements (talking, yawning, etc.). This can lower the effectiveness of the ear plugs, sometimes considerably. When this happens, the plugs will need to be adjusted by pressing them further in (or, if necessary, by removing and re-inserting them). It is very important to check frequently that ear plugs have not loosened. This can be done by pressing them in at frequent intervals. Another way of telling is to listen carefully to the sound. It will be louder if the ear plugs have loosened. However, because we get used to louder sound very quickly, we can find it difficult to realise that it has become substantially louder.
Remove ear plugs slowly. We have heard of a case where someone perforated his ear drum by removing an ear plug quickly.
The noise reduction achieved by foam ear plugs falls each time the plugs are rolled into a small diameter cylinder ready for insertion. So, it is important to replace foam ear plugs with new ones frequently. Our personal experience is that to maintain high performance, they should be replaced after being rolled twice at most.
It is much easier to fit ear muffs correctly than ear plugs. Make sure the whole ear is inside the muff seal. A good seal between the user’s head and the muffs is crucial. Remove long earrings and push hair back such that they are not under the muff seals. If you wear glasses this can lower the noise reduction because it interferes with the seal. The loss of performance is usually relatively small unless the glasses have thick or wide side arms.
Make sure the headband is on top of the head. Do not over-stretch the headband by pulling the muff cups a long way apart because this reduces the effectiveness of the seals. If the pressure from the headband is uncomfortable, try a different type of ear muff.
To maintain performance, the seals and entire muffs must be replaced from time to time. Ask the manufacturer’s advice on how often to replace them. If the seals become damaged replace them immediately. If the headband tension becomes low (when this occurs, the cups are relatively easy to pull apart), replace the entire ear muffs.
Noise Nuisance Assessment
Noise nuisance is assessed differently from noise that is loud enough to cause hearing damage. Instead of using a set noise limit, noise nuisance is normally assessed relative to the background noise. This is done by measuring noise levels with the annoying sound occurring, then repeating the measurement in the absence of the annoying sound – this is called the background noise. Then two noise levels are compared. If the noise level with the annoying sound occurring exceeds the background noise by 10 dBA or more, local councils usually consider this constitutes a statutory nuisance. A difference of 10 dBA or more is usually considered sufficient evidence for the Council to issue a Noise Abatement Notice, requiring that noise levels be reduced by a certain amount and within a set time. Failure to comply can result in fines of up to £20,000.
Sometimes, local councils advise that the noise should be reduced even if it does not exceed the background by 10 dBA.
Aircraft and traffic noise is exempt from the noise nuisance laws. Under certain conditions, grants are provided for sound insulation to be installed in houses affected by high noise where a new road is built or major changes occur on an existing road, such as upgrading to a dual carriageway.
How to Reduce Noise Nuisance
The first step is to consider telling whoever is causing the nuisance that the noise is a problem and asking them to reduce it. A decision on whether to do this will depend on who is causing the nuisance and how well you get on with them. If a factory is causing the nuisance, contacting them first is usually the best course of action. If an aggressive neighbour is causing the nuisance, approaching them directly may be inadvisable. If you decide not to contact the cause of the nuisance directly, or if your initial approach to them fails, ring up the Environmental Health Officer at your local Council. The Council have to investigate a complaint, and if they agree that the noise constitutes a nuisance, they will take noise abatement action. Initially, this means contacting the person or company causing the nuisance and asking them to reduce the noise. If necessary, they can enforce this by issuing a Noise Abatement Notice requiring that a noise reduction solution is implemented.
There are some very common myths about noise. One is that planting trees or shrubs on the boundary of your garden will reduce the noise transmitted into your garden and house. But it takes about a 100 metre wide band of densely planted shrubs and / or trees to achieve a 10 dBA (decibel) noise reduction. It is commonly considered that a 10 decibel reduction sounds equivalent to halving the sound level. So, you would need to plant a 100 metre wide band of dense shrubs / trees to make the sound appear half as loud. Planting a small number of shrubs or trees will have no effect on the sound at all.
Soundproofing in buildings is another area where a little knowledge can be misleading. There are many people, including builders, who install soundproofing but are not experts in sound control. This means that although some sound reduction may well be achieved, it is often considerably less than if it had been designed by a professional noise consultant.
Noise nuisance from factories can be reduced in a number of ways. Common methods include acoustic barriers and noise control enclosures. A better option is to reduce the noise at source using engineering or technologically advanced solutions. This type of solution can often achieve the necessary noise reductions at considerably lower cost than common solutions such as barriers and enclosures. For more details and some examples on this low cost type of solution for machines in a factory, click on industrial noise abatement service.
Note: our legal disclaimer applies to the information on this page. Click on legal disclaimer for details.