Noise-Induced Hearing Loss (NIHL)


Noise-induced hearing loss (NIHL) is the only completely preventable form of hearing loss. NIHL is typically caused by loud noises that damage to the “hair” cells (stereocilia) in the inner ear.

  • About 40 million US adults aged 20-69 years have NIHL

  • More than 1 in 2 US adults with hearing damage from noise do not have noisy jobs

  • About 1 in 4 US adults who report excellent to good hearing already have hearing damage



There are three key factors that affect whether and by how much a sound will damage hearing:

  1. Decibel level: Loudness of sound.  

  2. Distance: Closeness of sound.

  3. Duration: Length of exposure to sound.


NIHL can result from a one-time exposure to a very loud noise, like a nearby explosion or a shotgun firing.


Gradual hearing loss is more likely due to repeated exposures to unsafe sound levels at home and in community:

  • Listening to loud music through headphones, at a concert, or playing an instrument.

  • Going to the movies in theaters or cranking up the volume on the TV at home.

  • Going to sporting events attended by large, noisy crowds.

  • Going to fireworks shows.

  • Working with loud power tools.

  • Using a leaf blower.


Hearing might return to normal a day or two after initial exposures; but repeated exposures lead to damage without being noticeable.

As hearing gets worse, certain sounds—particularly speech—begin to sound muffled.

The 4Ps of NIHL are:

  • Painless

  • Progressive

  • Permanent

  • Preventable


CDC Vital Signs Report  

Analysis of >3,500 hearing tests conducted on adult participants:

  • Damage - shown by a distinctive drop in the ability to hear high-pitched sounds - appeared as early as age 20.

  • Almost 1 in 4 adults ages 20-69 who reported good to excellent hearing already had some hearing loss. 

  • Almost 1 in 5 adults who reported no job exposure to noise showed hearing damage indicative of noise exposure.

  • The presence of hearing loss increased with age, from about 1 in 5 (19%) among young adults ages 20-29 to more than 1 in 4 (27%) among adults ages 50-59.


Wear appropriate Hearing Protection Devices.

  • Awareness of NIHL risks and adopting safe listening behaviors.

  • Limiting ambient and audio sound exposure to recommended safe listening standards. 

  • Seek intervention, e.g. hearing aids, at early signs of impairment. 

See  for more information

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