By Dr. Kevin Liebe, Audiologist in Federal Way

When we think of potentially dangerous noise exposure, most of us think of gunshots, loud music or maybe a jet engine.

But, did you ever consider that your backyard fireworks display could be a hazard to your family’s health? Well, it just might be.

Despite the growing restrictions and bans in many cities and counties across our state and the nation, Americans are continuing to buy fireworks at a brisk pace. Sales of consumer fireworks have more than doubled over the past decade, according to the American Pyrotechnic Association. Industry revenues have soared to over $900 million in 2007. Clearly, based on sales figures alone, more and more Americans are coming into contact with fireworks.

Exposure to hazardous noise is one of the most common causes of irreversible hearing loss. It likely accounts for about one-third of all the hearing impairments in the U.S., which is currently estimated at around 30 million people (and climbing). Symptoms of noise-induced hearing loss tend to be subtle in the earlier stages. Hearing loss tends to occur first for high-pitch sounds. As a result, the bass or “volume” of speech appears unchanged, but the clarity of speech decreases. The ability to communicate in the presence of background noise becomes increasingly difficult and can cause anxiety, stress and fatigue for the individual trying to understand speech.

Not all loud sounds will result in hearing loss. Dependent upon the intensity and duration of the noise, temporary or permanent damage to the cells of the inner ear can occur. A ringing or buzzing sound in the ears, called tinnitus, is a common side effect and may become permanent.

As an audiologist at Puget Sound Hearing Aid and Audiology, I frequently see individuals whose hearing loss can be attributed to noise exposure. Some of these individuals will require amplification in order to hear speech, while others with only minimal damage may not. Our practice currently offers customized hearing protection for industrial workers, musicians, sport shooters and anyone else who may be routinely exposed to high levels of noise.

For the average person who is only occasionally around loud sounds, a set of foam earplugs is usually sufficient in most cases.

Prolonged exposure to sounds exceeding 80 decibels (dB) can result in permanent hearing loss. The louder the noise, the less time an individual can be exposed before permanent damage will occur. For example, a person can be exposed to 85 dB for approximately eight hours before there is a significant risk of permanent hearing loss. Every 3 dB increase in the intensity of the sound is equivalent to twice the risk of hearing damage. Thus, a sound of 88 dB is only safe for about four hours without hearing protection and a sound of 100 dB is only safe for about 15 minutes. Taking this into consideration, some aerial firework displays have been recorded to exceed 120 dB at more than 500 feet away. Sounds exceeding these levels pose a significant and immediate risk of permanent hearing damage. Firecrackers are particularly concerning in this regard. At a distance of just under 2 feet, this author has recorded firecracker blasts greater than 170 dB.

Noise-induced hearing loss is preventable. Fireworks pose a significant and immediate risk to your family’s hearing health. Despite this fact, I encourage everyone to go out and enjoy their local fireworks display this year, but please do so safely.

Disposable earplugs are a cheap and easy alternative to risking permanent hearing loss. If you experience a muffled sensation to your hearing after being exposed to loud noise or your ears are ringing, you should attempt to rest and avoid noise for at least 24 hours. If your symptoms continue after several days, you should have a medical examination by an otolaryngologist (ear-nose-throat physician) and a hearing assessment by an audiologist.

Dr. Kevin Liebe is an audiologist at Puget Sound Hearing Aid and Audiology. He has presented research regarding the risk of hearing impairment posed by firecrackers at the 2008 National Hearing Conservation Association annual conference and will be co-authoring two upcoming articles regarding noise-induced hearing loss this fall in the research journal “Noise & Health.” Contact: www.pshearing.com or (800) 500-8243.