Straight Talk About Hearing Conservation Let’s get right down to it. Nearly 30 million Americans have some degree of hearing loss. And according to the American Academy of Audiology, about 17 million suffer from “nerve deafness” – a hearing loss that results from exposure to loud noise or music.

Around 15% of baby boomers, the first generation to crank up the volume, have this type of hearing loss – about the same percentage as their teenage children. Just 15 minutes of exposure to high-decibel noise or music can cause permanent hearing loss. That's right. Permanent. Research indicates that 30% of rock musicians have a measurable hearing loss. Classical musicians fare even worse - with up to 52% experiencing hearing impairment. That means that members of your praise band, your harpist, your worshippers and your sound crew are all at risk. The good news? Hearing loss can be prevented.

Let’s start with a basic understanding of how the audio gear you were born with – your ears – actually function. Your ears process audio frequencies between 20 Hz and 20,000 Hz. Audio frequencies between 500 and 4000 Hz are the frequencies that we associate with speech. A Sensitive Instrument

A typical rock concert can average between 110 and 120 dB SPL (Sound Pressure Level), even in locations with local noise ordinances. According to the organization H.E.A.R. (Hearing Education and Awareness for Rockers), “At rock shows, the dB level can be as great as 140 dB SPL in front of the speakers and about 120 dB SPL at the back which is still very loud and dangerous.” Probably, the best known example of alleged rock-related hearing damage is a Smashing Pumpkins concert in 2000 in which loudness levels reached 125 SPL decibels. The resulting litigation against the concert hall, the band, the promoters and the record label is probably still keeping lawyers busy. Loud music isn’t the only problem. According to music writer Bernard Sherman, “Such stereotypical guy-toys as guns, motorcycles, chainsaws and snowmobiles can punish you ears just as badly – so can leaf blowers; so can some digital movie theater soundtracks. About 30 million Americans – more than one in ten – are exposed every day to dangerously loud levels of noise. And lasting damage can even come from a single blast of noise if it’s loud enough”

Hearing loss is classified according to which part of the auditory system is affected. There are three types of hearing loss: conductive, sensorineural (the “nerve deafness” type that’s largely preventable and includes the Noise-Induced type we’re talking about here) and mixed. Conductive Hearing Loss Conductive hearing loss is the result of disorders in either the outer or middle ear, which prevent sound from getting to the inner ear. Voices and sounds may sound faint, distorted or both. Some common causes of conductive hearing loss: Infection of the ear canal or middle ear Perforation or scarring of the eardrum Foreign objects in the ear canal Most conductive hearing loss can be helped medically or surgically if treated promptly. Sensorineural Hearing Loss Sensorineural hearing loss (also called Nerve Deafness) occurs when inner ear nerves become damaged and do not properly transmit signals to the brain. But sensorineural hearing loss can also be caused by: Illness or injury Heredity Excessive noise exposure It’s the most common type of hearing loss among adults. It is not often medically or surgically treatable. Most sensorineural hearing loss can only be treated with hearing aids (but more about those later). Mixed Hearing Loss If a hearing loss is the result of both conductive and sensorineural components, it is known as a mixed hearing loss. Focus on Noise-Induced Hearing Loss Excessive sound exposure damages hearing by over-stimulating the tiny hair cells within the inner ear. There are between 15,000 and 20,000 of these microscopic sensory receptors. When they are damaged, they no longer transmit sound to the brain.

Prolonged exposure to sounds above 85 dB SPL may cause permanent hearing loss. Exposure of 115 db of greater may pose a serious health risk. OSHA – the Occupational Safety and Health Administration – specifies the following as thresholds for potential hearing damage

This means that 15 minutes at the back of a concert hall where the decibel level is 120 SPL or greater can cause your hearing to be damaged forever.

Sounds are muffled. Human speech is difficult to understand. And the damage is permanent since the hair cells do not repair themselves or regenerate. This is the sensorineural type of hearing impairment that’s called Noise-Induced Hearing Loss (NIHL). This kind of hearing loss may be accompanied by tinnitus, an experience of sound like ringing, buzzing or roaring in the ears or head, which may subside over time. It may be experienced in one or both ears, and tinnitus may continue constantly or intermittently throughout a lifetime. The effect from impulse sound can be instantaneous and can result in an immediate hearing loss that may be permanent. The damage that occurs slowly over years of continuous exposure to loud noise is accompanied by various changes in the structure of the hair cells. It also results in hearing loss and tinnitus. Exposure to impulse and continuous noise may cause only a temporary hearing loss. If the hearing recovers, the temporary hearing loss is called a temporary threshold shift. The temporary threshold shift largely disappears within 16 hours after exposure to loud noise.

Given the statistics, it appears that if you were born after 1946, the answer is a loud “yes”. According to the House Ear Institute (HEI), “Advances in the electronics industry have made possible clean sound production at higher sound pressure levels. This has resulted in an average sound increase of 10-15dB in the work environments of musicians, audio engineers, record and movie/television producers, post-production mixers, dancers and other entertainment professionals.” Self-Quiz 1. Do you have trouble understanding certain words or parts of words? 2. Do you often ask others to repeat themselves? 3. Do you have difficulties on the telephone? 4. Do others complain about television or radio volumes? 5. Do you have more trouble understanding people in noisy environments? 6. Do sounds seem muffled? 7. Do you experience ear discomfort like ringing or buzzing in the ears? If you’ve experienced some or all of these indicators, you may be prone to Noise-Induced Hearing Loss (NIHL). It’s time for a visit to the audiologist. Keep this in mind – even if you have experienced a degree of loss — it is NOT TOO LATE to preserve your hearing. NIHL is not a degenerative condition … unless you ignore it. Ten Things You Can Do to Preserve Your Hearing Here are some general tips for diminishing potential damage to your hearing: Limit the amount of time you spend in a loud environment Wear hearing protection when involved in a loud activity. Forget about tissue or cotton – these homemade devices only reduce noise by about 7 dB. They’re not effective. Be alert to noise levels in your environment. If you know a gig will be longer than usual, decrease the intensity level. Increase distance between you and the sound source – this means standing at an angle from the source – not in front of it. Take breaks during long sessions to give your ears a rest. Be aware of the symptoms of hearing loss – listen to your own ears. Turn it down when listening to headphones – keep volume at moderate levels. Have your hearing checked by an audiologist. If you think you’re risking your hearing as a result of prolonged exposure, (for instance sounds in excess of 85 dB SPL) buy a sound pressure level meter and measure SPL against the OSHA requirements. And keep this in mind: Friends don't let friends take risks - alert your singers, musicians and sound crew, too.

Personal monitors, like Shure’s PSM Series, offer hearing conservation advantages when used properly. With the isolation afforded by personal monitors, worship musicians can hear their monitor mixes more clearly at lower volumes than necessary with traditional floor wedge or stage monitors. This allows you to control onstage volume levels. Where to set that volume level is the key, just as it would be when you use earphones for your MP3 player or laptop. Our best advice: Consult an audiologist who can test the levels as you use your personal monitor.

Shure has adopted hearing conservation as the company's corporate cause. The Shure Bid for Hearing program helps raise awareness of this serious problem among musicians, sound engineers, music fans, and anyone else in the live sound industry who may be exposed to potentially dangerous noise levels. In 2002, the program was created to help educate the public and raise funds for non-profit organizations dedicated to this cause. Shure has awarded funds to the Kresge Hearing Research Laboratory at Louisiana State University, the House Ear Institute (HEI), and Hearing Education and Awareness for Rockers (HEAR). Grants are used to fund research studies, provide free hearing screenings and create educational materials for the public. To learn more about Shure Bid for Hearing and the hearing conservation organizations that we support, please visit www.shure.com/hearing.

Also in this issue: Hearing Conservation    Dr. Heargood: Sensaphonic's Mike Santucci New Frontiers: The Charlie Hall Interview Two Artists Speak About Hearing    The Shure Calendar Product Spotlight: Shure Earphones    Shure Notes™ Archive Change My Preferences    E-mail to a Friend     Privacy Policy