Chances are you make at least part of your living with your ears. Stop and think about it. Could you perform your job as well…would your income level be the same…would your professional reputation be intact if you suffer severe hearing loss?
Both musicians and the live sound technicians who work with them need to be able to hear things. Not just hear them well, but hear them better than the average person. This should make us stop and consider our own hearing health, and the environments that we work in.
What have you done for…(and to) your ears lately?
Did you have your head deep inside a bass bin, listening for a 60-cycle hum, when somebody pushed “play” on the CD player? Were you walking past the tri-amplified sidefill stack, with your ear at compression driver level, when the lighting crew’s ladder knocked the center stage vocal mic stand over into the floor wedge to induce non-stop feedback? Did the drummer hit his primary crash cymbal, hard, 3 inches from your ear, while you were on the drum riser adjusting the hi-hat microphone?
Each of these typical events can be a daily occurrence on a typical concert stage, but any one of them might be the accident that causes you to have either temporary or permanent hearing loss. This could result in a shortened career and a decreased ability to earn a living with your chosen skill.
Accidents are one thing. Constant and intentional exposure to high sound levels is yet another. Did you just finish a 50-show run in tiny concert clubs with that new speed metal band? Was your powerful cue monitor wedge placed on end only one foot from your right ear as you mixed stage monitors for that entire world tour? Do you check 64 house mic line inputs every day with a ragged set of stereo headphones while listening to a clipping headphone amp?
Chances are good that your ears at least need a rest; but there are also certain techniques that can be employed to offer the maximum amount of protection to your hearing as you continue to do your job.
Earplugs are now in use more and more frequently by ushers, security guards, video crew persons, and others who must work at their job while surrounded by the high-level sound intensity of today’s rock music concert programs.
Throw-away foam-type plugs are often issued on a daily basis at arenas and auditoriums for the working crews; some facilities have a nurse or public health official who will provide these items to any member of the general public audience who complains about loud sound levels.
If you’re a technician who works around powerful sound systems, but is not actually responsible for mixing sound during the show, it is a good idea to have some sort of hearing protection device handy.
The same is true if you are a sound professional who is waiting around for your band to come on while listening to someone else operate a loud system. Here are some basic options:
Disposable Foam Plugs. This type of hearing protection device comes in a small cardboard or plastic pouch, and several can easily be stuffed in a shirt pocket or a briefcase pouch. They are disposable, intended for one-time use. Common brands include E.A.R., and DeciDamp from North Health Care. Such devices offer a noise reduction rating of about 12-20 dB, depending on frequency. These plugs mainly reduce high frequencies.
Re-usable Silicon Insert Plugs. These rubberized insert cushions conceal tiny metal filtering diaphragmatic mechanisms to attenuate sound levels. They are often seen in use by gun buffs, construction workers and heavy equipment operators. The Sonic Valve II comes in its own plastic storage case with a key chain attached, and offers about a 17 dB noise reduction rating. Often available in gun shops or industrial safety supply stores, a pair can run from $15-20.
Personal Custom-Fit Earmolds. The best hearing protection device, and the one most applicable to working around musical sound, is one that attenuates all frequencies evenly. When correctly designed and properly fitted, custom-molded flexible plastic earmolds can offer 15-20 dB of balanced noise level reduction; in other words, full-frequency sound is still heard, but at a reduced level. There are numerous suppliers, who provide custom fitting services as well, such as Sensaphonics.
Industrial Headsets. When maximum attenuation of very loud sounds is desired, particularly at low frequencies, the cushioned headset works well. Offering up to 30 dB of attenuation, hearing protectors from David Clark have cushioned headpads and tight-fitting earseals. This is also an option for person who do not wish to stick standard earplugs inside the ear. This is the type of protection often seen in use on airport runways and in the cabs of tractors and heavy cranes at construction sites.
Protecting Your Hearing On The Job
Use mini-nearfield monitors as a cue system for live mixing instead of headphones whenever possible.
By placing one or two small, powered monitors at your mixing console position and giving them the output from your stereo cue bus, you are able to solo up a mic input or an output mix and hear the signal without having to put on regular stereo headphones.
Roland, KRK, Yamaha, Tascam and other musical-instrument oriented manufacturers offer a variety of compact products.
This is particularly handy during setup and sound check. Using this method, you’ll have less loud, direct sound putting pressure on your eardrums, yet you will still hear the needed information.
Dummy headphones can be used as a quick way to lower the sound level of what you hear. Simply put on your regular stereo headphones, but don’t plug them into anything. Run the cord into your pocket. This will offer isolation from the louder acoustical environment that surrounds you during a show, while your ears have a chance to rest.
Rests away from the job site should be taken whenever possible. Remove yourself from the noisy environment and take time to have a meal, a nap, read a book, or whatever there is to be done in a quieter space. Focus on finding a ‘quiet zone’…no blaring TV or iPod headphones. This can mean a walk outdoors, finding a secluded dressing room, or whatever.
The important thing when working around loud sound levels is to give your hearing system and ear mechanism time to recover. If you work in a loud environment, your hearing will be more sensitive and ‘fresh’ if you take regular breaks like this.
Sound Level Meters
If you do not already include a hand-held, battery powered SPL meter in your working toolkit (or at least a decent app), get one.
Don’t rely on assumed level readings from your 1/3-octave real-time analyzer unless you are absolutely sure that the correct microphone is in use, (mic sensitivities can vary greatly, causing erroneous SPL readings), and that the system is properly calibrated. It’s better to have a small portable unit that you can keep in front of you on the mix console, or carry around the venue with you as you check coverage.
These handy devices can range in price from $10 to $3,500. I recommend the General Radio 1565-B Sound Level Meter; this is a hand-held battery powered meter that is approved by US Government agencies for environmental noise measurements. With its OSHA certification sticker, it helps you stand up to noise regulation officials, many of whom may have less sensitive and reliable gear.
Almost any type of SPL meter will do what you need; the accuracy difference between the cheapest and the most expensive can be about 1-2%…this would mean a possible error, plus or minus, of 1-2 dB at around 100 dB SPL. The more sophisticated, expensive units are best for critical situations.
Learn the difference between ‘A’ and ‘C’ weighting filter scales (US Government agency guidelines stipulate the use of C-weighted measurements for noise environments dominated by frequencies below 500 Hz; A-weighted measurements are most useful for making comparative readings in live show environments and discussing levels with others).
Use the sound level meter to get useful information in the front rows, the high balcony, the back of the hall, at the console…wherever you need to know the actual, average sound pressure level of your show.
Find the ideal ‘pocket’ where your show mix is as exciting and powerful as it needs to be, yet where you do not get audience complaints about excessive volume.
Use your meter as a daily reference guide, regardless of the type of acoustical environment.
Paying attention to the level of your system’s operation will be one more step toward protecting your own hearing, as well as that of others.
Long-Term Effects Of Loud Sound
We have probably all experienced TTS (Temporary Threshold Shift) after being exposed to very loud music or other sounds. This is the sensation that someone has stuffed cotton in your ears after you have already walked out of a loud environment; after one or two hours of high-level listening, your shifted hearing threshold may compensate as much as 40 or 50 dB.
In other words, your ears have ‘shut down’ to reject the extra-loud sounds that you have exposed them to. Recovery may take from a few hours to several days.
Prolonged exposure to very loud music can bring on tinnitus, which is a ringing sensation that you hear in your ears, even though no loud sounds are present around you. If you experience this ringing several days after exposure to a powerful sound system, consider that to be your own body’s way of giving you a danger signal. Heed the warning.
Have a regular hearing checkup. Get to know your audiologist or hearing specialist. Once or twice a year, get checked for both air and bone conducted sound sensitivity, speech understanding, and make sure that your inner ear parts are functioning properly.
If your job involves working with live sound, and you want to continue doing it, take time to carefully consider what your own personal approach is going to be as you work to conserve your hearing. You are also preserving your livelihood in the process.
David Scheirman is the dIrector of Global Concert & Rental Business for Bose Corporation, Professional Systems Division and president-elect of the Audio Engineering Society. He is also a long-time contributor of pro audio and sound reinforcement editorial.