Noise-induced hearing loss

Noise induced hearing loss (NHL) is hearing loss caused by sounds that are too loud (high decibel level) and damage hearing cells in the ear. This can make noises sound quieter as well as make noise less clear, it can also cause other hearing related symptoms such as tinnitus. NHL is permanent and cannot usually be restored.

Most of the time, NHL happens after being around a lot of noise for long periods of time. Listening to loud music, city traffic or even things like a hair dryer for can damage hearing after a while. But NHL can also happen suddenly when close to an extremely loud sound. This can come from things like being close to an airplane or a gunshot.

Signs of NHL

Hearing is a very important sense. It can be hard to notice hearing loss, especially if it happens over time instead of suddenly. Even if it is hard for a person experiencing it to notice, it will still have a large effect on their life.

Not being able to hear a conversation when there is a lot of noise around is usually a good sign of hearing loss. Other people may sound like they are speaking softly or their speech may not be clear. Both of these can be signs of NHL. Similarly, having to ask people to repeat themselves and having to try very hard to hear people speak are also signs.

Apart from not being able to hear very well when talking to other people, there are other signs of NHL such as tinnitus as well as some other diseases and medication.

Preventing NHL

Since NHL causes permanent damage, knowing the signs and causes of it and preventing it early is the only way to keep hearing healthy.

• Lowering the volume of sound is a good way to start. Even though controlling the level of sound heard is not always possible, when listening to music or watching movies it can be done and will keep hearing from being damaged.
• If controlling the level of sound is not possible then avoiding being around loud sound for a long time will help too. This is because the level of sound is not the only thing that is important for hearing loss, how long this loud sound is present is important as well.
• If none of the above methods to prevent hearing loss are possible, then using earplugs or earmuffs is a must. This will reduce the sound that is able to reach and cause damage to the ears. This is useful for people who work in places that are loud such as a construction site.

Treatment

Although NHL is permanent and most of the time cannot be cured, there are ways to manage it.

The most common thing to do is use hearing aids. Hearing aids can help with hearing loss by making sound louder and speech clearer. They can also be customised by audiologists to suit almost any lifestyle and to suit the specific needs of different people.

Noise-induced Hearing Loss Media

• This animated video illustrates how sounds travel to the inner ear, and then to the brain, where they are interpreted and understood. The cochlea in the inner ear is a spiral-shaped organ that contains hair cells, which sense sound vibrations. Hair cells convert sound vibrations into chemical signals that the auditory nerve can understand.

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  The outer ear receives sound, transmitted through the ossicles of the middle ear to the inner ear, where it is converted to a nervous signal in the cochlear and transmitted along the vestibulocochlear nerve

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  Example audiogram of a notch-shaped high frequency hearing loss.

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  Cross-section of the cochlea. The inner hair cells are connected to afferent nerve fibers, and the outer hair cells are connected to efferent nerve fibers.