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Why do loud noises cause your ears to
ring?
by Cristen Conger
Browse the article Why do loud noises cause your ears to ring?
Why do loud noises cause your ears to ring?
Human Senses Pictures
Dr. Fred Hossler/Getty Images
Hair cells within the inner ear contain bundles of hair-like extensions that convert sound.
See more human senses pictures.
Think back to the last time you went to a rock 'n' roll concert or a fireworks display. Do
you remember that peculiar ringing in your ears after the show stopped? The noises
around you were muffled briefly, replaced with a buzzing inside your head, almost as if
your ears were screaming. In a way, they were.
Noise levels louder than a shouting match can damage parts of our inner ears called hair
cells. Hair cells act as the gatekeepers of our hearing. When sound waves hit them, they
convert those vibrations into electrical currents that our auditory nerves carry to the brain.
Without hair cells, there is nothing for the sound to bounce off, like trying to make your
voice echo in the desert.
Hair cells reside in the inner ear inside the shell-shaped cochlea. Bundles of hair-like
extensions, called stereocilia, rest on top of them. When sound waves travel through the
ears and reach the hair cells, the vibrations deflect off the stereocilia, causing them to
move according to the force and pitch of the vibration. For instance, a melodic piano tune
would produce gentle movement in the stereocilia, while heavy metal would generate
faster, sharper motion. This motion triggers an electrochemical current that sends the
information from the sound waves through the auditory nerves to the brain.
Learn More
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How Hearing Works
How to Care for Your Ears
Discovery.com: Sound in the Brain Video
When you hear exceptionally loud noises, your stereocilia become damaged and
mistakenly keep sending sound information to the auditory nerve cells. In the case of
rock concerts and fireworks displays, the ringing happens because the tips of some of
your stereocilia actually have broken off. You hear those false currents in the ringing in
your head, called tinnitus. However, since you can grow these small tips back in about
24 hours [source: Preuss], the ringing is often temporary.
Read on to find out exactly how something invisible like sound can harm our ears, how
you can protect those precious hair cells and what happens when the ringing never stops.
How can sound hurt you?
How loud is that? (in decibels)
Ringing telephone = 30
Normal conversation = 60
Lawn mower = 90
Chain saw = 110
Ambulance siren = 120
Rock concert = 140
12-gauge shotgun = 165
[Source: National Institute of Occupational Safety and Health]
Imagine cramming the power of an electric guitar solo into something smaller than a
marble, and you'll understand how incredibly strong, yet delicate, our auditory system is.
Sound travels in waves that enter our bodies through our ear canals. The waves cause our
eardrum in the outer ear to vibrate, passing the sensory information along to the bones in
the middle ear where that sound is amplified. It then moves to the inner ear and the peasized cochlea, where the hair cells come in, as we discussed earlier. The force of those
vibrations can snap the tips of the cells' hair-like extensions and cause the lingering ring,
signaling that the noise was too loud.
Photo courtesy of NASA
The human auditory system. The cochlea is the seashell-shaped part of the ear that houses
the hair cells.
Repeated exposure to loud noises can kill the hair cells entirely. So what? We have
16,000 of them in each cochlea, but that number pales in comparison to the eye's 100
million photoreceptors, which do to light what hair cells do to sound. In addition, once
those hair cells die, we cannot growth them back. This is why protecting your ears is
essential.
Celebrities with Tinnitus
In addition to stalkers and paparazzi, tinnitus can be another unpleasant side effect of fame. Here's a
rundown of some celebrities with chronic tinnitus and how it happened:
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Steve Martin: a loud explosion on the set of "Three Amigos"
William Shatner: stood too close to an explosion on the set of "Star Trek"
Pete Townsend: rocked out for too many years with The Who
Neil Young: months of grungy reverb and distortion on the 1991 "Ragged Glory" tour
How loud is too loud? Sound is measured in units called decibels. Decibels measure the
power of sound, rather than the amount. Safe sound levels are considered below 85
decibels. Here's another rule of thumb: If you have to shout to hear someone an arm's
length away, the sound is probably above that safety threshold.
Repeatedly crossing that 85-decibel threshold can have unpleasant consequences. While
the ringing in your ears from a loud noise is usually brief, for more than 12 million
Americans, it never stops [source: American Tinnitus Association]. Chronic tinnitus can
be a symptom of infections, high blood pressure and compacted earwax, but it is
commonly associated with noise-related hearing loss.
There are a few simple ways to safeguard your hearing. First, be aware of the noise levels
around you. If you know you're going to be in a loud environment, such as a rock
concert, wear earplugs. Also, notice how close you are to the source of loud noises and
how long you're exposed to them. And pay attention to the ringing in your ears. Our
bodies are sometimes more fragile than we think.
What's that? Still curious about how your hearing works? Visit the related links on the
next page.
Lots More Information
Related HowStuffWorks Articles
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How Hearing Works
How to Care for Your Ears
Tinnitus
9 Home Remedies for Ringing in the Ears
How Hearing Aids Work
How Noise-canceling Headphones Work
More Great Links
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American Tinnitus Association
National Institute on Deafness and Other Communication Disorders
National Institute for Occupational Safety and Health Noise Meter
Sources
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American Tinnitus Association. "About Tinnitus." 2007. (Feb. 13, 2008)
http://www.ata.org/abouttinnitus/index.php
Goldberg, Jeff. "The Quivering Bundles That Let Us Hear." Seeing, Hearing and Smelling the
World. 1997. Howard Hughes Medical Institute. (Feb. 15, 2008)
http://www.hhmi.org/senses/c120.html
Hudspeth, James. "Hair cells of the inner ear." The Rockefeller University. (Feb. 15, 2008)
http://www.rockefeller.edu/labheads/hudspeth/hairCells.php
Mayo Clinic. "Tinnitus." Aug. 2, 2006. (Feb. 13, 2008)
http://www.mayoclinic.com/health/tinnitus/DS00365
MedLine Plus. "Tinnitus." Feb. 19, 2007 (Feb. 13, 2008)
http://www.nlm.nih.gov/medlineplus/ency/article/003043.htm
National Institute on Deafness and Other Communication Disorders. "The Noise in Your Ears:
Facts about Tinnitus." February 2001. (Feb. 13, 2008)
http://www.nidcd.nih.gov/health/hearing/noiseinear.asp
National Institute on Deafness and Other Communication Disorders. "Noise-Induced Hearing
Loss." May 2007. (Feb. 13, 2008)
http://www.nidcd.nih.gov/health/hearing/noise.asp
The Royal National Institute for Deaf People. "Look after your ears." April 2005. (Feb. 13, 2008)
http://www.rnid.org.uk/VirtualContent/84927/look_after_your_ears.pdf