What is noise-induced hearing loss?

One of the most common causes of hearing loss is exposure to loud noise. This is known as noise-induced hearing loss.

Noise-induced hearing loss can occur instantly or gradually over time, and can be temporary or permanent. The symptoms will depend on whether it’s the result of long-term exposure to noise, or a sudden, single burst of very loud noise.

You can develop noise-induced hearing loss at any age. The CDC reports that around 5.2 million children and adolescents in the US live with a degree of permanent hearing loss caused by excessive noise.

This figure rises to 26 million adults aged 20 to 69 – around 17% of the population of that age.

Noise-induced hearing loss treatment is limited to wearing hearing aids or, if the degree of hearing loss is severe or profound, you might benefit from a cochlear implant.

What is noise-induced hearing loss?

Most sounds you experience in your day-to-day environment are at safe levels and don’t damage our hearing.

But, sounds that are too loud can be harmful to your ears and cause damage to your hearing and cause noise-induced hearing loss.

Noise-induced hearing loss is any degree of hearing loss resulting from exposure to loud sounds.

That can happen if you spend prolonged amounts of time exposed to intense noise – for example, if you work for many years in a factory where loud machines constantly operate.

In these cases, hearing loss is likely to develop over time and you might not notice any change in your hearing for a while.

When your workplace is the source of your hearing damage, it’s known as occupational noise-induced hearing loss.

Damage can also occur after you’re exposed to extremely loud noise in a single, explosive bang or a short burst – like a shotgun going off or a particularly loud fireworks display.

This is sometimes called acoustic trauma. If this happens, you’re likely to notice something’s wrong straight away.

Noise-induced hearing loss causes

Any noise that’s loud and long-lasting, or short-lasting but too loud, can cause noise-induced hearing loss.

Sound is measured in decibels (dB), and even sound that you’re used to hearing in your everyday life can start to damage your hearing.

The louder a sound becomes, the shorter the time it could take to cause hearing loss.

Sounds louder than 85dB can cause hearing loss after around two hours of exposure, while just two minutes spent close to the source of noise at 110dB could potentially cause loss of hearing.

Sources of loud noise that can cause hearing loss include:

• Gunfire
• Explosives
• Heavy machinery
• Power tools
• Jet engine
• Lawn equipment
• Emergency alarms
• Concerts and theaters
• Musical instruments
• Personal music players
• Sporting events
• Heavy traffic or motorcycles.

You’re at increased risk of developing noise-induced hearing loss if you’re in an environment with these noises for any extended time period.

As a result, noise-induced hearing loss is more likely to affect you if you work in certain industries. Data from the CDC suggests that around 25% of all workers have been exposed to noise at harmful levels.

Jobs that carry the highest risk include those in agriculture, construction and carpentry, mining/oil and gas extraction, and the military.

If you’re a veteran and developed hearing loss because of your service in the military, you might be eligible for free or subsidized hearing aids.

Some hobbies – such as hunting and shooting, listening to loud music through headphones, and going to loud concerts and sporting events – can also cause noise-induced hearing loss. This is sometimes called sociocusis.

Noise-induced hearing loss can happen at any age. Although your chances of developing it increase with age, around 17% of young people aged 12 to 19 are thought to have noise-induced hearing loss.

How does noise damage hearing?

Noise-induced hearing loss is caused by damage to the tiny hair cells in the cochlear.

In normal hearing, these hair cells convert the soundwave vibrations into electrical impulses, which travel through the auditory nerve to the brain. The brain then interprets these electrical impulses as sounds.

When the hair cells become damaged, they die off and don’t grow back, meaning they are unable to convert soundwaves into electrical impulses and preventing the signals from reaching the brain.

Noise-induced hearing loss symptoms

When you’re exposed to loud noise over a long period of time – usually many years – your hearing loss is usually very gradual. That makes it hard to detect until it gets worse.

Symptoms are similar to those you’d experience with other types of hearing loss, including difficulty understanding speech, especially in noisy environments, and muffled or distorted hearing.

This type of hearing loss is usually caused by damage to the microscopic hair cells in the inner ear. The outermost hair cells, which detect high-frequency sounds, are most exposed to noise, so they’re usually damaged first.

As a result, one of the first things people with noise-induced hearing loss often notice is difficulty with high-frequency sounds, like children’s or higher-pitched voices and birdsong. It may also be difficult to distinguish certain consonant sounds, like ‘s’, ‘sh’, ‘f’ and ‘th’.

A common symptom of noise-induced hearing loss is tinnitus, commonly known as ringing in the ears – although you might experience it as humming, buzzing, whooshing, or hissing.

If a single, sudden loud noise or burst of loud noise damages your hearing, you might experience ear pain as well as abrupt hearing loss. Other people may tell you you’re shouting or talking very loudly.

There is a phenomenon called diplacusis, or double hearing – where each ear hears sounds very differently, creating a distressing perception of sound.

Double hearing can be a symptom of sudden noise-induced hearing loss, especially if it’s only in one ear. However, this is rare.

How is noise-induced hearing loss diagnosed?

If you think you have any type of hearing loss, including noise-induced hearing loss, the first step is to visit an audiologist.

They will perform some hearing tests to assess the degree of hearing loss and identify any other treatable contributing factors, such as blockage (wax, for example) in the ear canal.

If you’re an older adult, your decline in hearing might be due to a combination of age and noise exposure.

There is no specific test that can determine if your hearing loss is caused entirely by exposure to noise, or whether you also have age-related hearing loss, or presbycusis.

The outcomes of your tests will help determine the best treatment.

Noise-induced hearing loss treatment

If you’re diagnosed with noise-induced hearing loss as a result of a sudden, intense noise – or acoustic trauma – your doctor might advise you to monitor whether it improves.

Sometimes, noise-induced hearing loss is temporary and your hearing will return within 48 hours. However, even if your hearing appears to return to normal, you may experience long-term damage to your hearing.

When noise-induced hearing loss is permanent, your audiologist will probably recommend you wear a hearing aid.

Living with noise-induced hearing loss

It can be difficult and frustrating to come to terms with any type of hearing loss. Because it’s a barrier to communication, it can make you feel increasingly isolated. In turn, that often leads to depression and anxiety.

This may well sound worrying, but having your hearing assessed and finding a suitable treatment – typically a hearing aid that’s suited to you – will help you to cope better with hearing loss.

In addition, there are steps you can take to prevent your hearing from getting worse unnecessarily.

For example, try to minimize how often you’re exposed to very loud noise, wear ear protectors or ear plugs, and if you’re watching TV or listening to music, resist the temptation of turning the volume too high.