Noise: Bad for Your Hearing, Bad for Your Health!!
Noise is dangerous, all around us, and can painlessly and silently steal our hearing. Noise exposure is the most common cause of hearing loss and can result is difficulty sleeping, high blood pressure, and digestive problems. Noise can affect our ability to concentrate and learn and can result in poor social and emotional behaviors (i.e. anger, depression. anxiety).
Noise is one of the most common causes of hearing loss, and one of the most common occupational illnesses in the United States. A single shot from a shotgun, experienced at close range, may permanently damage your hearing in an instant. Repeated exposures to loud machinery may, over an extended period of time, present serious risks to human hearing.
10 million Americans have already suffered irreversible hearing damage from noise
30 million are exposed to dangerous noise levels each day
The effects of noise on hearing are often underestimated because the damage takes place so gradually.
Why has this problem become so widespread? Unfortunately, the effects of noise are often underestimated because the damage takes place so gradually, loud noises have become so common in our culture, and (although traumatizing to the parts of the body responsible for hearing) there are no externally-visible physical changes (like bleeding). As a result, people have traditionally not appreciated the serious impact of noise-related hearing loss on their daily living until they’re frustrated by a permanent communication problem. Perhaps a bit too late, they then become passionate about “hearing conservation,” in order to save the hearing they still possess. Doesn’t it make more sense, though, to emphasize “HEARING LOSS PREVENTION,” when you have good hearing sensitivity? This document will summarize how excessive noise can damage the hearing system, factors that influence this damage, and actions that you can take to prevent hearing loss.
Excessive noise damages the delicate hair cells in the inner ear. This damage results in sensorineural hearing loss and often tinnitus (ringing of the ears). Dangerous levels of noise can come from working in noisy occupations or in engaging in dangerous recreational activities:
Dr. Vowell in Sand Dune National Park in Florence, Oregon where she is demonstrating an example of a noisy recreational activity! Four wheelers can be very loud and hearing protection and helmets are needed safety precautions.
Beware of dangerous RECREATIONAL activities: Video arcades, fire crackers, discos, music concerts, shooting a gun, movie theatres, sporting events, motor boards, motorcycles, snowmobiles, four wheelers, and “boom cars”.
OCCUPATIONS particularly under risk for hearing loss due to exposure to noise are as follows:
- Aviation/Jet Engine Industry
- Firefighter & Police Officers
- Factory Workers/Warehouse Workers
- Construction Industry
- Military Personnel
- Heavy Industrial Workers
- Entertainment Industry Professionals
Every day, we enjoy sounds. But, when an individual is exposed at work or at home to harmful sounds – those that are too loud or loud sounds over a long time – sensitive structures of the inner ear can be damaged, causing noise-induced hearing loss (NIHL). NIHL is characterized by a gradual, progressive loss of high frequency hearing sensitivity over time, as a result of exposure to excessive noise levels. Figure 1 illustrates this typical progression, in which the pattern of noise-induced hearing loss usually shows a “notch” that is usually seen at or near 4000 Hz. In later stages, the hearing loss may spread to frequencies that are more critical to understanding human speech (in the range of 500-3000 Hz). NIHL usually occurs bilaterally (in both ears). However, the hearing loss may not necessarily occur equally between the left and right ears when the exposure conditions favor one side of the head. It is even possible to see a unilateral hearing loss, as can happen in acoustic trauma, when a loud blast affects the ear nearest the explosion.
Progression of hearing loss following exposure to loud noise
(95 dBA, averaged across the work day. Data show hearing loss for white males at ages 20, 30, 40, 50 and 60 years with 0 – 40 years of exposure, respectively). (ANSI 3.44-1996)
When the hearing system is exposed to excessive noise, mechanical and metabolic changes can occur from this stress. Scientific research, based on studies of industrial workers, as well as lab studies of humans and animals, have investigated the effects of noise on hearing. This work has determined that, after excessive noise has stimulated cells in the inner ear, chemical processes occur that can exceed the cells’ tolerance, damaging their function and structure. This damage results in sensorineural hearing loss (as opposed to a conductive hearing loss, where the outer or middle ear have been affected) and tinnitus (ringing of the ears). The sensory cells in the cochlea may recover from their damage (as you have possibly experienced after a loud concert or work with a loud machine). Usually, recovery from temporary threshold shift (or TTS) occurs quickly, largely disappearing in 16 to 48 hours after exposure to loud noise. However, if the hearing sensitivity does not recover within a few days, an irreversible permanent threshold shift has taken place. Loud explosions (that peak for a few milliseconds at levels greater than 130-140 dB) may cause hearing loss. More often, however, hearing loss is caused by repeated exposure to noise above 85 dBA over long periods. The risk of noise-induced hearing loss depends on both the intensity and duration of the exposure. As intensity increases, the length of time for which the exposure is “safe” decreases. As a result, someone exposed to 85dBA (often produced by gas-engine lawn mowers) for 8 hours may be equally at risk for noise exposure after using a chain saw (producing 110dBA) for only a few minutes.
What are the symptoms of Noise Induced Hearing Loss (NIHL)?
NIHL develops gradually so that people may lose a significant amount of hearing before becoming aware of its presence. During the early stages, sufferers often report having to turn up the volume on the TV or have difficulty understanding speech in groups or in the presence of background noise. As the hearing loss worsens, it becomes difficult to understand normal conversation even in quiet, one-on-one situations. The individual may not be aware of the high frequency hearing loss, but it can be detected with a hearing test. In fact, early identification is important in order to recognize the presence of NIHL and then take steps to prevent further hearing loss.
Some of the Warning Signs of the presence of or exposure to hazardous noise are as follows:
You can’t hear someone three feet away
You have pain in your ears after leaving a noisy area
You hear ringing or buzzing (tinnitus) in your ears immediately after exposure to noise
You suddenly have difficulty understanding speech after exposure to noise; you can hear people talking, but you cannot understand them.
What You Can Do to Protect Your Hearing
NIHL is preventable. Although hearing normally declines with age, the average, healthy, non-noise-exposed person can have essentially normal hearing at least up to age 60. Individuals vary in their susceptibility to hearing loss. While research has shown some trends, there currently is no reliable way to identify which particular individuals may be most susceptible to NIHL. To protect themselves when exposed to hazardous noise, everyone should take these precautions:
- If you work in an at-risk occupation, check with your employer to make sure you have adequately protected your hearing according to OSHA regulations.
- Limit exposure time to noisy activities.
- Wear hearing protection, such as foam or silicone plugs or muffs. Foam plugs are available at your pharmacy while muffs and specialized ear protection can be purchased at sporting good stores or safety equipment stores.
- At home, turn down the volume on the television, radio, stereos and walkmans.
- Wear ear plugs or muffs when using loud equipment (i.e. lawn mowers, power saw, leaf blower).
- Buy quieter products (compare dB ratings – the smaller the better).
- Reduce the number of noisy appliances running at the same time in your personal environment.
- Avoid medications that can be dangerous to your hearing. Be sure to ask your physician about possible effects on your hearing.
Many toys can be dangerously loud. Infants or young children have shorter arms than adults and therefore usually listen to toys closer to their small, sensitive ears. Noise-induced hearing loss among children is a serious public concern and can cause delay or reduce speech and language development and result in learning, social, and/or emotional disabilities. Hearing loss affects almost 13 out of every 1,000 children under age 18, some resulting from exposure to noise.
Personal Stereo Systems
Personal stereo systems with headphones can produce sounds as loud as a motorcycle. While guidelines have been established to protect hearing in the work place, consumers must take full responsibility for preserving their hearing.
Get a stereo system with an “Automatic Volume Limiter” to limit output.
Limit the amount of time you use headphones, and do not interchange headsets with other systems.
Set the system to a comfortable listening level in a quiet room. Do not turn it up in a noisy setting to “block out” noise. Rule of thumb: If you cannot hear other people talking or if other people have to shout to be heard at 3 feet away, it is too loud and could be damaging your hearing.
PROTECT THE HEARING THAT YOU HAVE NOW!
Custom Noise Plugs
The Hearing Doctor provides CUSTOM NOISE PLUGS which have an excellent NRR rating and because they are custom fit to only the individual ears they are made for they provide the best protection in noise! Custom noise plugs can be made in a variety of colors and styles… team colors are a popular favorite at The Hearing Doctor!
When properly selected and used, HPDs can be powerful tools for preventing NIHL. HPDs are required by law to be labeled with a Noise Reduction Rating (NRR) that is based on performance obtained under ideal laboratory conditions. Usually, people obtain far less protection than the labeled rating because they do not wear the devices correctly, especially for foam or plastic non custom plugs, or neglect to wear them during the entire period of the noise exposure. It must be emphasized that the best hearing protector is not the one with the highest NRR, but the one that people will consistently wear whenever exposed to loud noise.
Audiology Dr. Brandy Vowell, your Tulsa Audiologist, is pleased to provide answers to your hearing protection concerns.