Say What?

Before you hear thebad news about permanent hearing injury; and the good news aboutincreasingly affordable, high-quality protection; it'simportant to understand the exquisite yet vulnerable ear
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I lay on the hotel bed, flat-out wasted. I'd spent the day walking around the 2001 Winter NAMM convention (the annual trade show for all kinds of musical gear), so my feet hurt. Far worse, I'd spent the evening with Spinal Tap, proudly known as England's loudest rock band.

I'd brought my trusty custom-fitted earplugs to the concert, of course, and I had beamed approvingly at the ticket takers who offered foam plugs from big bowls at the door. Nevertheless, Spinal Tap lived up to its reputation (Nigel's amp was definitely at “11”), and my pocket SPL meter routinely clocked the sound at 118 dB. I was plugged, it was great fun, but it was loud! By the time I crashed, my ears were ringing — roaring like surf on the residue of too much noise.

Most bands don't approach Spinal Tap's dizzying decibels, but these days 100 dB or higher is normal for smaller rooms. That's more than enough to do real damage during the typical three- or four-hour club gig. If you regularly perform at these levels, you're at serious risk for hearing loss. But before you hear the bad news about permanent injury — and the good news about increasingly affordable, high-quality protection — it's important to understand the exquisite yet vulnerable ear.

ANATOMY LESSON

Scientists divide the human auditory system into three areas: the outer, middle, and inner ears (see Fig. 1). These components form a delicate instrument that transforms acoustic energy into electrical impulses that the brain interprets as sound.

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FIG. 1: The human auditory system consists of three parts: the outer, middle, and inner ears. Noise-induced hearing loss occurs in the cochlea within the inner ear.

The outer ear gathers and directs sound through the ear canal to the eardrum or tympanic membrane. The eardrum vibrates in response to the acoustic energy and transmits this vibration to a series of three tiny bones, called the ossicular chain, in the middle ear. The last bone in the chain sends the vibration into the fluid-filled inner ear, or cochlea, a structure coiled like a snail shell.

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FIG. 2: These are electron micrographs of cochlear hair cells. The ones on the left are healthy, whereas the ones on the right have been damaged by noise exposure.
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Extending the entire length of the cochlea is a small, flat structure called the basilar membrane, covered with more than 30,000 microscopic hair cells (see Fig. 2). Think of a fuzzy carpet on a coiled, spiral-shaped ramp. Each hair cell responds to a particular frequency, depending on its location between the base of the spiral (high frequency) and the end or apex (low frequency). The hair cells are also connected to sensory nerve fibers.

As the incoming vibrations travel through the cochlear fluid, they stimulate different areas of the basilar membrane to vibrate, depending on which frequencies the sound contains. The hair cells in each area generate electrical impulses in the corresponding nerve endings. The fibers of the auditory nerve then transmit these electrical signals to the brain.

In addition to frequency, the intensity or amplitude of the sound is encoded into the electrical impulses. However, when the intensity is too great for too long a period, it can damage the hair cells. Once hair cells collapse or die, contact with the nerve fibers is broken, and the perception of a particular frequency range is reduced or lost entirely.

Noise-induced hearing loss (NIHL) is the most common occupational injury, according to government statistics. In activities such as mining, manufacturing, and woodworking, NIHL is a side effect that may not interfere with the primary task. But for musicians and audio professionals, it distorts and then destroys the most important tool of your trade.

Overexposure to high sound levels can also lead to tinnitus, a debilitating ringing, buzzing, or roaring in the ears. An hour with Spinal Tap after a day at NAMM (with instruments and sound gear blaring from almost every booth) gave me some moderate tinnitus, which fortunately went away by morning. But if I worked in such a loud environment for a long time, I could develop permanent problems.

NIHL is insidious and irreversible, but it is also preventable. Like cigarette smoking or unsafe sex, exposure to high sound levels brings real dangers. So don't sacrifice your future musical enjoyment — and your livelihood — for a quick bone-buzzing blast. Take the long-range view and play it safe. Protection is up to you.

WORK RULES

Damage to the hair cells of the inner ear occurs with long-term exposure to sound-pressure levels (SPL) of 90 dB and above. The Occupational Safety and Health Administration (OSHA) defines long-term as eight hours per day for ten years. However, the higher the sound level, the faster the damage accumulates (see Fig. 3).

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FIG. 3: The louder the sound, the less time you can safely be exposed to it without protection.

The OSHA standard cuts the safe exposure time in half for every 5 dB above 90. In other words, 95 dB is considered safe for four hours, 100 dB is safe for two hours, 105 dB is safe for one hour, 110 dB is safe for half an hour, and so on. In other countries, these guidelines are 5 to 10 dB lower, and studies show that at 85 dB long-term exposure will definitely cause hearing loss in a certain percentage of those exposed.

Consider that rock concerts at sustained levels above 100 dB can easily last three hours or more, placing everyone's hearing at risk. Last year, in a series of articles in the Bay Area Reporter on the blaring levels at dance clubs, journalist Ed Walsh documented music as high as 115 dB at the loudest club in San Francisco. That's not quite as bad as Spinal Tap, but it's worse than sandblasting. If this club were a factory, workers would legally be allowed in for only 15 minutes a day. Yet very few patrons or employees were observed wearing hearing protection of any kind.

MUFFLER SHOP

NIHL does not reduce hearing response evenly across the frequency spectrum. Typically, problems are first noticed in the 3 to 4 kHz range, although losses at higher frequencies may already exist. Boosting overall levels to compensate — or just pushing the high end as you lose sensitivity there — is like having whiskey for breakfast to blot out a hangover. It makes matters worse in the long run, and if you're rocking the house that loudly all the time, it also hurts everyone around you.

NIHL comes on slowly, so how do you know you're in trouble? You may notice temporary effects after a gig, such as ringing in your ears or the sense that everything sounds muffled, or you may notice that you hear better with one ear than the other on the phone. Often soft, high-frequency sounds (such as the fizzing when you open a can of soda) disappear entirely.

These symptoms may come and go at first as the hair cells in your cochlea struggle to recover from each onslaught. But with repeated exposure, things get worse. Eventually the perception of all frequencies is permanently reduced, and additional ongoing symptoms, such as tinnitus or hyperacussis (hypersensitivity to sounds), may bring further discomfort and distress.

In addition, keep in mind that the frequency range from 3 to 5 kHz contains most spoken consonants — so with the onset of NIHL, normal speech may seem mumbled. (See the sidebar “DIY Hearing Test” for a simple early-warning test that uses speech sounds on the radio.) When guitarist Pete Townshend went public with his hearing problems in 1987, he said the saddest part was not being able to hear his children speak to him.

Prevention, protection, and early detection of hearing problems are essential for a long-term music career. Simple measures, such as avoiding nonmusical noise, can make a big difference. Any situation in which you must shout to be heard is likely to cause damage. Alcohol consumption, cigarette smoke, and marijuana have been shown to reduce the ear's resiliency, so cleaning up your act in those areas may benefit your hearing as well.

TAKE THE TEST

Where should you begin? Michael Santucci, president of Sensaphonics, a manufacturer of custom in-ear monitors (IEMs) and earplugs, explains that the cornerstone of hearing conservation is a thorough assessment by an audiologist, including an interview about your health history, musical habits, and other sources of noise exposure, such as outdoor hobbies or past military service. The audiologist will also ask about symptoms such as ear pain, temporary decreases in hearing sensitivity, or tinnitus.

He or she will then test you to establish a pure-tone hearing profile or audiogram that reveals the softest level or threshold at which you respond to various frequencies (see Fig. 4). (OSHA regulations specify that such a test is valid only if preceded by at least 14 hours of quiet time, so don't schedule your audiology appointment for the morning after a late, blasting gig!) If the interview or audiogram indicates that you have a problem that requires medical follow-up, the audiologist will refer you to an ear, nose, and throat physician.

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FIG. 4: A hearing test produces an audiogram. Unlike most, this audiogram includes two measurements: typical readings for normal and noise-damaged hearing.

It's a good idea to schedule an annual checkup even if you don't notice any symptoms. These tests can catch subtle problems early, and if your hearing turns out to be normal, you'll have a baseline for future comparisons — and you'll feel a sense of relief. Keep in mind that the typical hearing test goes up only to 8 kHz; you should shop around for an audiologist whose equipment can measure response to frequencies as high as 12, 16, or even 20 kHz.

Hearing Education and Awareness for Rockers (HEAR), a San Francisco-based nonprofit organization, offers evening clinic appointments staffed by volunteer audiologists. Its Web site also provides a nationwide list of affiliated audiologists and doctors specializing in hearing conservation and tinnitus treatment who will understand your particular needs as a musician. (All audiologists on the HEAR Web site use equipment that tests above 8 kHz; those with a university affiliation may have access to research equipment that tests up to 20 kHz. See “Onstage Hotlinks” for this and other Web resources.)

DITCH THE HALL MONITOR

In rehearsal and performance, musicians need to hear themselves. But not everyone wants to hear everything, and cranking your own axe over the others just leads to competitive, potentially painful mush. So for musicians who want to maintain safe sound levels, an IEM system should be top priority.

According to Marty Garcia, president of IEM manufacturer Future Sonics, the first IEMs were developed in the mid-'80s in response to a different concern: vocal fatigue. Professional rockers needed to hear their singing over the rest of the mix to avoid blowing out their voices. Touring artists also wanted consistent monitor sound, independent of the acoustics in each hall.

These personal monitors were originally simple ear-bud headphones, a concept later refined into custom-molded earpieces, similar to those made for hearing aids. Garcia reports that in the early '90s Steve Miller recognized that as a bandleader (employer), he could be held legally liable for hearing damage to his entire crew, and he invested in research indicating that IEMs have the potential to offer better hearing protection than room monitors. (They can also cause more damage if misused.) Miller also required his band members to get annual hearing tests, and he specified in his contracts that house levels be kept under 90 dB.

Other pro musicians soon picked up the idea, with drummers among the earliest converts. According to Stephen Ambrose, another pioneer in the development of IEMs, country musicians were also especially receptive early on, because a lower-intensity, clearer monitor mix suited delicate instruments, such as the mandolin and fiddle, as well as their lyric-oriented material and typically smaller venues.

For the first time, musicians also had individual control of what they heard, using belt packs connected to the mixer with cables or wireless transceiver systems. (Companies such as Shure, Sennheiser, Nady, and AKG offer wireless systems.) Still, it quickly became clear that given the chance, players tended to listen at potentially damaging levels. In fact, an IEM in the ear canal has the potential to be even louder and more damaging than a stage monitor. To prevent that, Garcia explains, sound engineers must learn to set a safe peak limit, and each musician can then set his or her own level between 80 and 100 percent of that limit.

Custom-molded IEMs include the Westone Labs Ultimate Ears ($500 to $750), Sensaphonics ProPhonic ($650 to $850), and Future Sonics Ear Monitor brand ($798). Westone and Sensaphonics offer several models within their respective lines, including single- and dual-driver designs. To obtain a set, contact one of these companies for a referral to an audiologist in your area who can fit you for the product. (The prices quoted here are for the earpieces only — expect to spend considerably more on the other hardware components of your IEM system.)

When fitting you for custom-molded IEMs, the audiologist first determines if you have excessive wax in your ear canals; if so, it must be removed. (Some audiologists do this themselves, or you might need to see a doctor.) Once your canals are clear, the audiologist squirts a thick silicone goo into each ear, which hardens after a few minutes into impressions of your ear canals. The audiologist then sends these impressions to the manufacturer, which makes the IEMs.

Custom-molded IEMs are relatively expensive, so several companies offer universal models. Future Sonics recently developed a universal IEM in collaboration with Sennheiser; called the EM3 ($200), it includes a covering of expandable foam, which provides a semicustom fit at a more affordable price. Other universal IEMs include the Etymotic Research ER-4 MicroPro ($330) and the Shure E1 single-driver ($193.80) and E5 dual-driver ($601.80).

Keep in mind that gear alone won't save your hearing. As Sensaphonics' Santucci puts it, “The biggest problem is that people think they're safe because they use IEMs. But you still have to be responsible and not turn them up too loud.” Garcia recommends that musicians use stereo monitoring because they can achieve greater clarity and separation at a lower overall SPL than with a mono system.

Dave Denny, a musician and engineer who has worked with Steve Miller and the Grateful Dead, makes an additional suggestion: add one or two mics pointed away from the stage and feed a bit of the audience sound into your monitor mix. This can overcome a performer's sense of being isolated and sealed off from the house ambience.

Audiologist and recording engineer Rachel Cruz emphasizes that musicians must maintain careful habits. “IEMs can be great for hearing conservation, or they can be a significant source of hearing loss,” she says. “It all depends on how you use them.” (For more on in-ear monitors, see “Stick It in Your Ear” in the April 2000 issue.)

LEAKS, SQUEAKS, AND PLUGS

If you can't afford IEMs, there are less expensive ways to protect yourself onstage. To reduce the SPL reaching your ears from floor monitors, get a pair of musician's earplugs, specially designed to provide relatively flat attenuation across the audible spectrum (see Fig. 5a). Keep your plugs handy for other loud environments, such as concerts, dance clubs, and movie theaters.

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FIG. 5: Custom-molded earplugs include Etymotic Research filters that attenuate by 9, 15, or 25 dB with a relatively flat frequency response across the spectrum (a). By contrast, typical foam earplugs do not exhibit a flat attenuation with either a shallow or deep insertion into the ear (b); they reduce the high end much more than the low end, resulting in a muffled sound. The Etymotic ER-20 universal earplug''s relatively flat structure avoids the muffling effect of foam plugs.

As with IEMs, you can choose between universal plugs, such as Etymotic Research's ER-20 ($10), and the custom-molded variety, which can cost around $150. Sensaphonics, Westone Labs, and Future Sonics offer custom musician's earplugs with interchangeable filters from Etymotic Research that attenuate 9, 15, or 25 dB. As with custom IEMs, contact one of these companies for a referral to an associated audiologist in your area.

Ordinary foam plugs from the drugstore are better than nothing, but they do not provide flat attenuation; in particular, they tend to cut the highs much more than the lows (see Fig. 5b). Compared to the rest of what you probably spend on gear, quality earplugs are a reasonable investment.

Many musicians complain that IEMs and earplugs can feel odd; for one thing, your own voice sounds different when your ear canals are blocked, a phenomenon called the occlusion effect. At quiet moments, the sounds of your own breathing, swallowing, and even blood circulation can become distracting head noise.

One common attempt to solve these annoyances is to add a vent to the earpiece. But venting destroys the plug's protective effect — it's like poking a hole in a condom. Instead, audiologists recommend that you experiment with different filters for different situations, using the lowest attenuation necessary to protect yourself adequately. After a while you'll get used to the new sensations, just as you once had to get used to the feel of your drumsticks, keys, or strings. You'll reap the reward of clear sound at safe levels, and you'll get home from a gig or a night on the town without suffering from muffled conversation or ringing in your ears.

Try not to worry about being seen as a wimp for taking these precautions. You're actually on the leading edge of a trend. Everyone I spoke with at NAMM said sales of safe-hearing products have grown phenomenally in the past few years. Baby boomers hitting midlife with as much hearing loss as retirees now take the problem seriously, but so do many in today's health-conscious younger generation.

At NAMM, Daniel East, marketing director for Future Sonics, described fitting the preteen members of a bubblegum-pop group with earplugs and IEMs. The kids had just signed a record deal, and their parents wanted to make sure they had hearing protection built in to their careers from the start. To make hearing protection more fashionable, Etymotic Research markets the ER-20 universal plugs in an assortment of bright colors.

Perhaps the niftiest gizmo I saw at NAMM eliminates the potentially harmful zap — to gear as well as ears — that occurs when you unplug a cord from a live amp. Made by Sensonics, the Silenzer snaps onto the end of any plug and grounds it during unplugging; when the cord is in use, this safety wire slips out of the way. It's an elegant solution that its inventor, Stephen Ambrose, hopes will become an industry standard for safety and convenience.

AFTER THE RAIN

What if you're already dealing with significant hearing loss? First of all, it's important to protect the hearing you have left. In addition, talk to your audiologist about hearing aids. According to Dr. Jillian Barrett of California State University at Hayward, the new fully digital hearing aids have a wide frequency response and extensive programmability so that they can closely match your particular area of loss. Some new analog aids, also designed with the musician in mind, may be more affordable.

Unfortunately, tinnitus sufferers have fewer options; coping strategies are the main focus of tinnitus-oriented Web sites and support groups. The most common suggestion is to mask the internal roar with white noise, especially if you have trouble falling asleep. The easiest way to do this is to tune a radio between stations.

If you have significant hearing loss, do your part to educate your less-afflicted colleagues. My most memorable encounter at NAMM was with a drummer in his mid-30s who already suffers from permanent, serious tinnitus. “Get the kids to pay attention,” he urged me. “They think that they're invincible and that hearing loss only hits grandparents. Ten years ago I thought that too, but my ears were already damaged, and I just didn't know it. Now, it's hard for me to sleep, it's hard to be anyplace quiet. I'm still young, and I can't enjoy music like I used to.”

So listen up — use your common sense and the available resources to take care of your ears. It's the only way to make sure you'll enjoy a lifetime of listening and playing, studio gigs and concerts, and all the hotel rooms in between.

Joanna Cazden is a voice coach in Burbank, California, who often writes about musicians' health issues. You can contact her online at www.voiceofyourlife.com.