Hearing Health/Preserving Hearing
"Hearing is a gift most people take for granted until they start losing it. Because the chronic din of ordinary life is higher than ever, reducing excessive noise can improve your hearing health, no matter your age. Make protection of your hearing part of your everyday lifestyle."
Simon C. Parisier, MD, co-director of The Cochlear Implant Center at The New York Eye & Ear Infirmary and founder of The Children's Hearing Institute.
Statistics on Noise Induced Hearing Loss
- More than 30 million Americans are exposed to hazardous sound levels on a regular basis. (National Institute on Deafness and Other Communication Disorders)
- Of the 28 million Americans who have hearing loss, over one-third have been affected at least in part by noise. (ASHA)
- Excessive noise exposure is the most common cause of hearing loss. (American Academy of Otolaryngology – Head and Neck Surgery)
- Audiology experts agree that hearing loss in the United States is increasing. The number of Americans age 3 and older with some form of hearing disorder has more than doubled since 1971. (National Institute on Deafness and Other Communication Disorders)
- Noise-induced hearing loss affects people of all ages. U.S. government survey data revealed that 12.5% of children ages 6 to 19 (approximately 5.2 million children) have permanent damage to their ears' hair cells caused by exposure to loud noises. In addition 15.5% of children ages 12 to 19 had some hearing loss in one or both ears, highlighting the fact that noise-induced hearing loss grows more prevalent with age. (Niskar, 2001)
- Noise-induced hearing loss is also growing among baby boomers. Of the more than 75 million Americans born between 1945 and 1964, 20.4% or 16 million people have some degree of hearing loss. (National Center for Health Statistics)
Age-related hearing loss affects one in three Americans over 65, nearly one in every two Americans over 75 and four out of five over the age of 85 (AMA). This is due to a variety of factors that accrue over time including exposure to loud noise over the years, medications that can contribute to hearing loss, and smoking, among others. (ASHA)
Niskar AS, Kieszak SM, Holmes AE, et al. Estimated prevalence of noise-induced hearing threshold shifts among children 6 to 19 years of age: the Third National Health and Nutrition Examination Survey, 1988-1994, United States. Pediatrics. 2001 Jul; 108(1):40-3.
Noise and Hearing Loss
Tiny hair cells in the cochlea are the nerve receptors for hearing. Signals from these hair cells are translated into nerve impulses that are sent to the brain via the acoustic nerve. Loud sound destroys these tiny hair cells in the inner ear that are responsible for converting sound waves into electrical impulses. Once 25% to 30% of these cells disappear, you begin to experience hearing loss.
Hearing damage can occur in two ways. Brief exposures to extremely loud sounds can cause permanent damage. Consistent exposure to moderate-level loud sounds wears out the hair cells in the inner ear and weakens their ability to recover. Over time as these cells die permanent hearing loss occurs.
More information on how the ear works and how hearing damage occurs can be found at:
Decibels: what are safe levels?
Decibels measure the loudness of sound. Both the amount of noise and the length of time of exposure determine the amount of damage. Damage can be caused to hair cells of the inner ear and the hearing nerve by one-time exposure to loud sounds like an explosion or by continuous or repeated exposure to noise. Sounds that are less than 80 decibels are unlikely to cause hearing loss. Noise levels greater than 80 decibels can be hazardous and can damage your hearing. Many experts agree that continual exposure to more than 85 decibels is hazardous to your hearing.
The noise chart below can act as a guide to the average decibel levels of everyday sounds and can help you judge which sounds are potentially dangerous to your hearing. It is important to note that as decibel intensity increases by units of 10, each increase is 10 times the lower figure. In addition, noise exposure is cumulative so be aware of your exposure to noise throughout the day - at work, home, traveling and in recreational settings. As a general rule, if you have to shout to be heard, then you should avoid the situation or use ear protection.
Dangerous levels:
- 150 dB = rock music peak
- 140 dB = firearms, jet engine
- 130 dB = jackhammer
- 120 dB = jet plane take-off, amplified rock music at 4-6 ft., car stereo, band practice
- 120 dB = ambulance siren
- 120 -140 dB = Motorcycles, firecrackers
Extremely loud:
- 105 dB = helicopter
- 100 – 115 dB = iPods used at maximum levels
- 100 dB = snowmobile, chain saw, pneumatic drill, night clubs
- 95 dB = motorcycle
- 90 dB = lawnmower, shop tools, truck traffic, subway
- 90 dB = noisy toys
- 80-96 dB = restaurants
Very loud:
- 80 dB = alarm clock, city street traffic
- 70 dB = vacuum cleaner
Normal levels:
- 60 dB = normal conversation
- 35 dB = whispered voice
Unsafe Levels of Exposure:
- 110 decibels or louder : regular exposure of more than one minute risks permanent hearing loss.
- 100 decibels: No more than 15 minutes of unprotected exposure is recommended.
- 85 decibels: Prolonged exposure to any noise above 85 decibels can cause gradual hearing loss.
ASHA
Center for the Advancement of Health
The National Institute on Deafness and Other Communication Disorders
University of Michigan: Noise and Hearing Loss
Sources of Noise Pollution
- Noise pollution can be encountered on the job. Working around heavy machinery, on busy city streets, or wherever loud music is played poses a risk to your hearing.
- Noise pollution also occurs in many everyday situations in the home and on the street. Using stereo headsets, operating power tools, leaf blowers and lawnmowers, spending time in heavy traffic, car stereo systems and many household appliances such as hairdryers, blenders, garbage disposals, vacuum cleaners, and food processors can expose you to levels of sound that are potentially dangerous to your hearing.
- Many recreational activities also involve dangerous levels of noise. Hunting, target shooting, motor boating, waterskiing, jet skiing, snowmobiling, woodworking, rock music, stereo headsets and iPods are sources of hazardous noise. Unsafe levels of noise can also be found in some movie theaters, dance clubs, bars, sporting events, and exercise centers.
- Children can be exposed to hazardous levels of noise through a variety of toys, such as those with horns and sirens, musical instruments, squeeze toys, and battery-operated toys that emit sounds.
- Various types of travel can also pose risks. Subways, airplanes, riding a motorcycle without protection and other transit noise are capable of causing damage to your hearing.
University of Michigan
iPods, personal cassette players and portable compact disc players
There is much concern about the effect of iPods and other MP3 players. Hearing loss is related to the volume and duration of sound. With these devices, music is blared directly into the ears, the volume is often high, and the devices hold thousands of songs that are listened to for long periods of time. Hearing specialists are reporting seeing teens with signs of noise-induced hearing loss that would not be expected until middle age. (Spencer J., 2006)
Researchers studying cassette players and portable compact disc players have found an increased risk of hearing loss among people who listen to loud music through headphones for extended periods of time. In one well-cited study recommendations were made to limit the use of portable CD players to one hour per day at 60% of maximum volume (Fligor, 2004). If you listen for more than one hour, the volume should be turned down below 60%. Maximum sound levels of CD players and iPods are estimated to be between 100 and 115 decibels.
A new set of guidelines presented in October 2006 by Fligor and Portnuff are based on a follow-up study that evaluated the output levels of several popular MP3 players to determine the risk to hearing from using these devices. The authors conclude that MP3 players appear to produce high enough sound levels to pose a risk of hearing loss if used at high volumes for extended periods of time. Complete details can be found at the National Hearing Conservation Association web site.
How to use IPods safely
The problem with IPods and other MP3 players is that we turn them loud enough so that we can hear the music and block out the street noise. This can make them dangerously loud.
To protect your hearing do the following:
- Set the volume while at home or in a quiet place (not in the street).
- Set the volume so that you can still hear sound around you and carry on a conversation.
- When you go into the street DO NOT MAKE IT LOUDER.
- OR buy noise canceling earphones that will block out the street noise so you do not have to turn up the volume to hear the music comfortably. Two possible sources of noise-cancelling ear phones are Bose and Etymotic.
In March 2006 Apple released a software update for iPods that allows parents to use a combination lock to set the maximum decibel level for their children. Apple posted information online at www.apple.com/sound on how to use this new feature and other strategies to limit long-term hearing damage.
Because of these concerns there is interest in new sound-minimizing headsets for music players. There are two styles of head phones. Noise-canceling headphones by Sony, Bose and Panasonic produce sound waves that cancel out ambient noise before it reaches the ear. Sound-isolating earphones by Shure and Etymotic are less expensive. They fit snugly in the ear and are made of sound-proof material that helps block out background noise which allows you to hear the music better at lower volumes.
Fligor BJ, Cox LC. Output levels of commercially available portable compact disc players and the potential risk to hearing. Ear & Hearing. 2004 Dec; 25(6):513-27.
Gregory Mott. The iPod and the Fury: A Reality Check of the Recent Reports on Mobile Music and Hearing Loss. The Washington Post. January 17, 2006 ; Page HE01.
Spencer J. Beyond the Music: iPods and Hearing Loss. The Wall Street Journal. January 10, 2006.
Protect Yourself from Noise
The optimum protection is to eliminate your exposure to unsafe levels of noise whenever possible. When noise cannot be eliminated, these strategies can help to limit the negative effects.
- Wear hearing protectors when exposed to any loud noise. Hearing protection devices decrease the intensity of sound that reaches the eardrum. Hearing protectors include ear muffs, foam plugs, pre-molded ear plugs, and canal caps. These can be purchased at drug stores, sporting goods stores or can be custom-made. Ear plugs are generally better for low frequency noise and ear muffs for high frequency noise. Properly fitted earplugs or muffs reduce noise 15 to 30 dB. However, there must be a complete air seal between the hearing protector and the skin for these devices to be effective. Check with your audiologist to find out what best suits you.
The following web sites describe devices to protect your ears from excessive noise:
- It is essential that musicians wear ear protection.
- When using stereo headsets or listening to amplified music in a confined place like a car, turn down the volume and ask others to do the same. If sound from a head set can be heard by others 3 feet away, the volume is too loud.
- Look for a noise rating when buying recreational equipment, children's toys, household appliances, and power tools. Choose quieter models, especially for equipment that you use often or close to your ears like a hair dryer. If there is no noise rating, you can contact the manufacturer and request this information. (ASHA)
- Avoid children's toys that produce high noise levels. This is especially important since children often hold toys close to their ear which exposes them to an added threat for hearing damage.
- Do not sit near speakers at concerts, festivals and sporting events.
- Avoid loud noisemakers such as firecrackers and guns.
- If you suspect hearing loss consult a physician or audiologist and get your hearing tested. Early detection and therapy can avoid serious damage as well as consequent speech disorders in children.
- There is a growing awareness of the dangers of noise induced hearing loss for children and adolescents. Excessive noise can adversely affect a child's hearing, language development, ability to learn and social interactions.
The Dangerous Decibels project is a public health campaign designed to reduce the incidence and prevalence of Noise Induced Hearing Loss (NIHL) and tinnitus (ringing in the ear) by changing knowledge, attitudes, and behaviors of school-aged children.
Their Teachers Resource Guide provides good background information and creative ideas for classroom activities that will raise awareness in children.
The Hear-It web site provides useful information in English, Spanish, French and German on noisy toys, noises to avoid, and other advice on hearing loss in children and adults.
Links
American Academy of Audiology
American Academy of Otolaryngology – Head and Neck Surgery
Noise and Hearing Protection.
ASHA (American Speech-Language-Hearing Association)
Noise and Hearing loss.
The Better Hearing Institute
Center for the Advancement of Health
Noise-Induced Hearing Loss: Common Condition Easily Prevented.
CDC
National Institute for Occupational Safety and Health, Best Practices in Hearing Loss Prevention.
H.E.A.R.
A nonprofit hearing information resource for musicians and music lovers.
The Hearing Foundation of Canada
Laurent LeClerc National Deaf Education Center
Noise and Hearing Loss
Mayo Clinic
Hearing loss: MP3 players can pose risk
National Hearing Conservation Association
NIDCD (National Institute on Deafness and Other Communication Disorders)
Have Wise Ears for Life
NIDCD
Noise-Induced Hearing Loss
NIH Consensus Development Program
Noise and Hearing Loss
University of Michigan
Noise and Hearing Loss
Noisy Toys Can Damage Young Ears
“From traditional noisemakers such as whistles, toy guns and musical instruments to talking dolls and animated stuffed animals, many toys are loud enough to cause permanent hearing damage,” says Paul R. Kileny, Ph.D., director of audiology and electrophysiology at the University of Michigan’s Health System's Department of Otolaryngology. Children's hearing is particularly sensitive. While the inner ear is completely developed at birth and has the complete complement of hair cells, the ear canal is much smaller, and sounds entering the ear canal become louder because they develop in a smaller space.
That can translate into as much as a 20-decibel difference between adult and infant ears; thus, infant ears can be damaged more easily than adults' hearing. In addition, children tend to hold toys or games closer to their ears because of the short reach of their arms. Dolls and stuffed animals are often held directly up to the ear-region. "When you make a judgment about whether or not to buy a toy or a game, you really have to hold it up close to your ear," Kileny says. "If a toy sounds loud to an adult, it'll sound much louder to a child."
In general, it is best if toys do not exceed 80 to 85 decibels (the measure of the intensity of a sound). A normal conversation is about 60 decibels, lawnmowers and shop tools run at 90 decibels or so, a chainsaw at 100, a rock concert at 115, and a jet engine at 120 or higher. In testing the decibel output of toy musical instruments, dolls, MP3 and CD players, and more, Kileny found that many exceeded the 80-85 level at which it is safe for children to be exposed to the sound for extended periods of time.
"There are some toys and games that produce sounds as loud as a jet plane taking off," Kileny says. "That amount of output can cause immediate and permanent hearing loss." Some musical instruments and music players designed specifically for children ages 3 to 5 can be excessively loud. An MP3 player marketed to toddlers, for instance, measured in at a peak of 120 decibels. Computer games often exceed 110 decibels. Musical instruments can peak at those levels as well.
Kileny notes that parents also can ask their doctors about possible changes in their children's hearing. "If you've observed that your child doesn't hear as well as your other children or friends, or that he or she doesn't hear as well as six months ago," Kileny advises, "bring this to your physician's attention and request referral to a licensed audiologist to determine the hearing status."
For more information, visit these Web sites:
UMHS Health Topics A-Z: Childhood hearing loss .
National Institute on Deafness and Other Communicable Disorders: Noise-induced hearing loss
American Academy of Family Physicians: How to prevent noise-induced hearing loss
KidsHealth: Choosing safe toys.
American Speech-Language-Hearing Association: Noisy toys, dangerous play
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