Exposure to loud noise is the most common cause of hearing loss. Noise-induced hearing loss (NIHL) can be prevented but you cannot get your hearing back once you lose it.
How does noise affect hearing?
Sounds entering your ear pass through your eardrum and into the inner ear. Tiny hairs in the inner ear change the sound waves into nerve impulses. Hearing nerves carry these impulses to the brain. The brain interprets the nerve impulses from the ear as sound.
You are born with about 30,000 hair cells in the inner ear. That’s all you get. The hairs in the inner ear are very sensitive and fragile. They can be destroyed by loud noise. If some of these cells are destroyed, your body does not make new cells to replace them.
What kinds of sounds cause hearing loss?
The hair cells in the inner ear can be destroyed by noise in 2 ways.
A sudden, very loud noise, such as an explosion, gunfire, or firecracker, can sometimes cause immediate damage to the hair cells and permanent hearing loss. The hair cells are destroyed in much the same way a hurricane knocks down trees. This is called acoustic trauma.
More often, the hairs are hurt by the stress caused by exposure to loud or hazardous noise for long periods of time. Ongoing noise creates chemicals that damage the hair cells. Everyday devices such as power tools, chain saws, blow dryers, or personal stereos can damage hearing in this way.
The loudness of sound is measured in decibels. For example, normal conversation is approximately 60 decibels. The humming of a refrigerator is 40 decibels, and city traffic noise can be 80 decibels. Sounds that are less than 80 decibels, even after long exposure, donâ€™t usually cause hearing loss. Noise levels greater than 80 decibels can be damaging. Motorcycles, firecrackers, and firearms can produce sounds of 120 to 140 decibels and can cause hearing loss.
Here are some sounds that can cause hearing loss after continued exposure:
At home: The noises in and around our homes can damage our ears. Examples of appliances and tools that can make sounds louder than 80 decibels are:
Blenders, electric mixers, coffee grinders, and garbage disposals
Lawn mowers and leaf blowers
Chain saws and other power tools
At work: Millions of Americans are exposed to harmful noise levels regularly at work.
Anyone who works around heavy machinery, on busy city streets, or wherever loud music is played is at risk.
Musicians and people who work in rock music venues aren’t the only ones who should worry. Many classical musicians also have job-related hearing loss.
Noise levels at concerts, where music is often louder than 120 decibels, can damage your ears in 10 minutes. Arena and stadium sporting events and car racing can be just as loud.
Gunshots, at 140 decibels or more, actually tear the insides of the inner ear.
Subways, airplanes, traffic on city streets, and other transit noises are often at an ear-damaging level.
Riding a motorcycle without protection can easily cause hearing loss.
What are the symptoms of hearing loss?
For most people, a noise louder than 120 decibels hurts. Symptoms of possible damage to your hearing after exposure to noise may include:
A buzzing, ringing, crackling, or roaring sound in your ears
A muffling of what people are saying to you
Feelings of ear fullness or pressure
These symptoms may start to go away after a few minutes or they may last a couple of days or longer. Buzzing or ringing sounds in your ear are called tinnitus. You may hear these sounds all of the time or just occasionally throughout your life.
As you are exposed to more and more noise, more cells are damaged and hearing loss can become permanent and more severe. You may not notice the hearing loss at first because it often happens gradually. The first noticeable symptom is not being able to hear higher pitched sounds, such as birds singing. Sounds may get distorted or muffled and it may be hard for you to understand speech.
How is hearing loss diagnosed?
Hearing loss is detected with a hearing test.
How is hearing loss from noise treated?
Once the ear’s tiny hairs are destroyed, they cannot be repaired. If you have a hearing loss from too much noise, the best thing you can do is to protect your ears from further damage by avoiding noise whenever possible. When you cannot avoid noise, use hearing protection. If you have hearing loss, hearing aids can often help you hear better.
How can I help prevent hearing loss from noise?
Hearing loss from noise can be prevented with these precautions:
Be aware of the level of sound in your home. Turn down the TV, stereo, music player, or radio. If someone else can hear the music coming from your headset, itâ€™s probably too loud and the volume should be lowered. Consider using a personal stereo that has an 85-decibel automatic volume limiter. When you shop for a new appliance, such as a dishwasher or air conditioner, ask about the noise levels of different models.
If you need to raise your voice above the noise in a room to be heard by someone an arm’s length away, the noise level is probably too loud to be safe for a long period of time.
Use ear protectors when you are around noise or other loud sounds. These devices can range from simple foam earplugs bought at the grocery store to custom earplugs molded to fit your ear. Earmuffs that look like big headphones also work well. Specially designed earplugs that bring the volume down without distorting the sound can be useful for musicians.
If you live in a noisy area, try to make your bedroom as quiet as possible. Consider using earplugs, or cool your room with an air conditioner or fans instead of open windows.
Make sure your car’s muffler and exhaust system are in good repair.
The government requires employers to provide hearing protection for employees in noisy work areas. Employers must also monitor the noise, provide hearing tests, and train employees about noise protection.
Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth. Last modified: 2013-03-25 Last reviewed: 2015-01-01
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Noise and Hearing Loss: References
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Basner M, Bobisch W, Davis A et al. (2014). Auditory and non-auditory effects of noise on health. Lancet; 383(9925):1325-1332.
Fuente A, Hickson L. Noise-Induced hearing loss in Asia. Int J Audiol 2011 Mar;50 Suppl 1:S3-10.