Exposure to loud or long lasting noise can cause noise-induced hearing loss. People of all ages can develop the condition, which can be immediate or gradual.

As many as 17% of teenagers and 24% of adults in the United States may have some degree of noise-induced hearing loss in one or both ears, according to the National Institute on Deafness and Other Communication Disorders.

This article discusses noise-induced hearing loss, including the causes, prevention, and treatment of the condition. It also answers some common questions about noise-induced hearing loss.

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A person may develop noise-induced hearing loss from exposure to a one-off, loud noise near the ear, such as a firecracker or gunshot. Alternatively, they may develop hearing loss over time from damage caused by repeated exposure to loud noises.

The louder a noise is, the faster it can cause hearing loss —and the longer someone hears loud sounds, the greater their risk of hearing loss. People measure sound in units called decibels (dB).

The Occupational Safety and Health Administration (OSHA) has occupational guidelines for occupational noise exposure. The permissible exposure limit for noise is a 90 dB average for all workers over an 8-hour day.

How noise damages hearing

People rely on a complex series of events to be able to hear.

Sound waves enter the outer ear, travel through the ear canal, and cause vibrations in the eardrum. The eardrum transports these vibrations to bones in the middle ear, which match the sound vibration to fluid vibrations in the cochlea of the inner ear.

As the fluid in the cochlea ripples, a wave travels along the basilar membrane, which is an elastic partition that splits the cochlea into two parts. Sensory cells, or hair cells, on the basilar membrane move up and down with this wave.

As the sensory cells move with the wave, microscopic protrusions called stereocilia on the hair cells bend, which opens pore-like channels in the tips of the stereocilia. When this occurs, chemicals rush into the cell, forming an electrical signal. The auditory nerve carries this signal to the brain, translating it into a sound people can recognize.

In noise-induced hearing loss, loud or long lasting noise damages the hair cells, which eventually die. This means they can no longer form an electrical signal for the brain to interpret as sound. These hair cells do not regrow and are lost forever.

Signs and symptoms of noise-induced hearing loss can include:

  • gradual muffling or distortion of sound
  • difficulty understanding speech in noisy environments
  • immediate hearing loss following exposure to a loud noise
  • tinnitus, which is a ringing or buzzing noise in the ears
  • dizziness
  • headaches

A loud, one-time noise, such as an explosion, can cause noise-induced hearing loss, or continuous noise over a long time period, such as working on a construction site, may lead to the condition.

Sounds over 70 dB — about as loud as a washing machine — may start to damage hearing over a long period of time. Loud noises over 120 dB, such as a siren next to the ear, could immediately damage hearing.

Risk factors include:

  • recreational activities that involve loud noises, such as target shooting
  • occupational noise
  • listening to loud music through headphones or earbuds
  • playing music in a band
  • home sources, such as leaf blowers, power tools, and lawnmowers
  • attending loud concerts or sports events

Other risk factors include:

Individuals can prevent noise-induced hearing loss. Some preventive measures include:

  • using ear protection in noisy places, such as ear plugs or noise-canceling headphones
  • avoiding noisy places where possible
  • keeping the volume at a moderate level when listening through earbuds or headphones and while watching television or listening to music
  • organizing check-ups with a doctor or audiologist, and discussing ways to protect the ears from noise

People cannot cure noise-induced hearing loss, as the damage to hair cells in the ears is permanent. However, a doctor can prescribe devices to improve hearing.

Hearing aids have a microphone and a speaker that detect sounds and send them to the ear. They make sound louder so people with hearing loss can pick up and understand sounds more clearly.

Cochlear implants are small devices that a surgeon inserts underneath the skin with electrodes or strings in the cochlea. The device bypasses the inner ear and causes the sensation of sound by stimulating the auditory nerve.

Below are some of the most common questions about noise-induced hearing loss.

Is noise-induced hearing loss permanent?

Noise-induced hearing loss is typically permanent. In some cases, a person may experience temporary hearing loss after exposure to a loud or continuous noise, which can disappear within 16–48 hours. However, although the loss of hearing recedes, there may still be long-term damage to a person’s hearing.

What are some common causes of noise-induced hearing loss?

Common causes of noise-induced hearing loss include:

  • music from personal listening devices, especially at loud volumes
  • events such as concerts, sporting events, movie theatres, and motorized sports
  • power tools
  • firearms
  • sirens
  • lawnmowers
  • firecrackers
  • occupational noise, such as construction site noise or workshop noise

How loud do sounds have to be to cause hearing loss?

Sound over 85 dB is more likely to cause hearing loss.

A person may develop noise-induced hearing loss after long-term exposure to noise, or exposure to a one-off, loud noise. Loud noises can damage the hair cells inside the ears, which play a vital role in hearing. These hair cells do not regrow, and without them, a person can experience permanent hearing loss.

As well as exposure to loud noises, risk factors include smoking, genetics, and aging. The best way for people to prevent this type of hearing loss is to avoid loud noises where possible and use ear protection in noisy surroundings.

There is no cure for noise-induced hearing loss, but a person may use certain devices to improve their hearing. These include hearing aids and cochlear implants.