Why Does Noise Cause Hearing Loss?

  • November 16, 2020
Why Does Noise Cause Hearing Loss?

Have you ever tried studying in a room where people were shouting over one another? Or maybe tried to carry on a conversation in a crowded bar, right next to a jukebox? Loud noises can be distracting and frustrating, especially when you’re trying to concentrate. Loud noises can also be damaging to your hearing. Understanding how and why loud noises can damage your ears can help you protect your hearing.

Inside your ear is a membrane we call the eardrum, which vibrates every time you’re exposed to sound. The eardrum is found in the middle ear. When exposed to sound, the eardrum passes vibrations to the cochlea, a snail-shaped bone containing 16,000 tiny hair cells. These hairs change vibrations into electrical signals that are sent to the brain through the hearing nerve. The brain interprets these signals, and this is how you hear sound.

Very loud noises, like the sound of an electric guitar in a rock concert, can damage the hair cells in the cochlea. Sometimes loud noises only flatten the hair cells, but after a few days, they straighten once again and normal hearing returns. Sometimes, loud noises cause the hair cells to die. When this happens, they do not recover. Between 30% and 50% of the hair cells in the cochlea must die before measurable hearing loss can be detected.

How Much Noise is Too Much Noise?

A single loud noise can cause hearing loss, if it is too loud and occurs too close to your ear. Usually, hearing loss from loud noises occurs slowly over many years. Repeated exposure to loud noises can cause damage to hair cells a little at a time, until notable hearing loss has taken place.

Normal conversation takes place at about 60 decibels (dB). A soft whisper happens at 30 dB. Repeated exposure to noises over 70 dB, continuously and over a long period, can damage your ears. Examples of sounds that occur at or above 70 dB include:

  • City traffic
  • Motorcycles
  • Leaf blowers
  • Subway trains
  • Very loud stereos

Some sounds, like firecrackers and sirens, can do instant damage if you are too close to them when the noises occur.

If you have to shout over the noise in a room in order to be heard, the noise is too loud and can potentially damage your hearing. Other signs that the noises around you are too loud include:

  • The noise is painful to your ears.
  • You’re unable to concentrate because of the noise.
  • You feel anxiety or irritability because of the noise.
  • Your blood pressure elevates when you hear the noise.

At Risk Populations

Some people are more vulnerable and more likely to experience hearing loss than others. People with a family history of hearing loss and people with hypertension/cardiovascular issues or diabetes are all common risk factors. People who smoke, older people, and people with iron deficiency or vitamin A deficiency are also at risk for hearing loss. These at-risk populations should take extra precautions to protect their hearing, although all people with normal hearing should be careful to protect their ears in certain circumstances.

Can Noise-Induced Hearing Loss Be Reversed?

Exposure to noise is the most common preventable cause of permanent sensorineural hearing loss. About 1/3 of the 30 million Americans with hearing loss have their condition at least in part because of exposure to loud noises.

Following a loud event like a rock concert, some people experience a change in hearing called a temporary threshold shift. People with this condition may hear a ringing in their ears, or have a hard time hearing softer noises for a while. Usually normal hearing returns in a few days. (Please note that if you have a sudden change in hearing and you were not exposed to loud noise around the time of hearing loss, you should seek medical attention immediately.  If caught within 72 hours, doctors can prescribe oral steroids that may help the inner ear recover.)

However, not all hearing loss is temporary. If the exposure to the noise was long enough, the threshold shift could be permanent. Once this damage is done, it cannot be reversed. Some research is being done to explore the possibility of preventing damage to the ears with vitamins and antioxidants, but at this time, there is no cure for noise induced hearing loss.

What Can You Do About Noise-Induced Hearing Loss?

Hearing devices can help people with partial hearing loss hear noises more clearly, which can help them regain quality of life. Hearing aids do not restore hearing, but a properly programmed hearing aid can help people with hearing loss engage in normal conversations, perform work at their jobs, talk on the phone.

There are many different styles of hearing aids, and they come with different features. Before getting a hearing aid, get a referral from an experienced and trusted audiologist. Your audiologist will assess your hearing and make a recommendation based on his or her findings. Talk about the options before making a decision. Purchase quality hearing aids that address your needs.

People who lose their hearing later in life must also grapple with their loss. Training family members to speak up, speak emphatically, deliberately and at a measured pace can help reduce frustration at home. Wearing good hearing aids is also important.

How Can You Prevent Noise-Induced Hearing Loss?

Prevention is key. Wearing protection on the job and while engaging in loud activities (like hunting) can help protect your hearing and prevent damage to the ears. If you work in a high-risk profession like construction or farming (where you may be routinely exposed to loud engines and large pieces of machinery), you can prevent hearing loss by wearing proper ear protection. Consult with OSHA to find out what you can do to protect your ears in your workplace environment.

Other things you can do to protect your ears include:

  • Minimize exposure to loud events like concerts or wear some hearing protection at those events.
  • Consult with an audiologist regularly to identify hearing loss in its earliest stages.
  • Minimize the amount of time spent wearing ear buds, listening to loud music.

Finally, just knowing the signs of hearing loss can help you seek help and take measures to protect your ears. If speech sounds muffled or far-away, you have a hard time following conversations in noisy environments or if you experience tinnitus (ringing in the ears), you could be experiencing hearing loss. Consult with an audiologist to get help. You may not be able to get back the hearing you’ve already lost, but you could prevent any more damage from taking place.

Sources:

1. CDC, How Does Loud Noise Cause Hearing Loss?https://www.cdc.gov/nceh/hearing_loss/how_does_loud_noise_cause_hearing_loss.html

2. DangerousDecibels.org, How Do We Hear?http://www.dangerousdecibels.org/virtualexhibit/2howdowehear.html

3. CDC, What Noises Cause Hearing Loss?https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html

4. MedicineNet.com, Noise-Induced Hearing Loss and Its Preventionhttps://www.medicinenet.com/noise_induced_hearing_loss_and_its_prevention/article.htm#how_can_a_person_tell_if_a_noisy_situation_is_dangerous_to_their_hearing

5. Mayo Clinic, Hearing Aids, How to Choose the Right Onehttps://www.mayoclinic.org/diseases-conditions/hearing-loss/in-depth/hearing-aids/art-20044116