Gyms make a racket. Whirring machines, feet pounding, weights clanging and thudding on the floor, fans overhead. Few people notice unless they’re the few without the popular aural accessory, the digital music player.
“I usually like to listen to more exciting music, stuff that pumps you up,” says Matt Conway, a 19-year-old kinesiology student at Dalhousie. “With an iPod you can just load everything you want on there and just make a playlist. On mine, I have a workout one, stuff to make me more into being there.” Music like Jay-Z, Lloyd Banks and techno. Third-year biology student Meaghan Lambert, 20, plays Destiny’s Child often these days on her iPod, saying she, like Conway, cranks the volume. “The louder it is, the more energy I guess I get and it blocks out the noise around.”
Lately iPods have become subjects of warnings about potential noise-induced hearing loss. It’s easy to demonize these little contraptions. However, the risk to hearing from all digital music players, not just iPods, results from a combination of technology and human behaviour.
First, look at the history, says Mark Gulliver, an audiologist at the Nova Scotia Hearing and Speech Centre in Halifax. Back when portable cassette and CD players were popular, people also cranked up the sound too much. “Loud is loud is loud,” Gulliver points out.
Nonetheless, subtle differences do exist with digital players. “They’re different, in a way, because the quality of the sound is better,” Gulliver adds. “There’s not as much distortion so you can turn it up and turn it up.” And echoing Meaghan Lambert’s point, Janine Verge, another audiologist at NSHSC, says, “We live in a noisier world, so as the background noise increases, people turn it up louder in their ears.”
The type of music plays a smaller role than you might expect. Both classical and popular forms include dangerously loud moments of “transience,” as Verge calls it. This occurs, for example, when, during a rock song, a cymbal crashes; in classical music, violins and violas are culprits. Suddenly the sound level peaks “up to 120 or 130 decibels. Sometimes just one or two instances of that can cause damage,” she says.
Add to this, Gulliver notes, the longer battery life and portability of slender digital players versus chunkier, analog players. Suddenly people listen to louder tunes for longer periods of time.
Gulliver has even observed people mowing their lawns while using the devices. “Imagine how loud you’d have to turn it up to hear anything,” Gulliver says with a shake of his head. A 2002 Workers’ Compensation Board guideline states “hearing loss results from a combination of high sound levels and extended periods of exposure to sounds above 85 decibels (dB).” A lawnmower runs between 80 and 95 dB, while personal stereos go from 60 to 115 dB, but don’t forget the transience when peak levels jump to 120 dB or more.
Damage occurs in the inner ear.
A coiled tube, called the cochlea, is lined with tiny cells with microscopic hairs. When a sound vibration comes in, the hairs move, sending nerve signals to the brain, which interprets them as sound. Noise-induced injury such as loud music flattens these hairs.
“It’s like grass blades. You walk over them, they go down but then they come back up.” Verge explains that this is called a temporary threshold shift. “But the more you walk across the grass, a path will form. Same with the hair cells: enough damage and they’re dead. They won’t grow back.” This is called a permanent threshold shift.
Eventually, riding around in a “booming car,” going to concerts unprotected (concerts reach 115 dB, the WCB reports) or to clubs where you have to yell to have a conversation (something student Meaghan Lambert does once a week, she says) will cause the same.
The first sign of hearing impairment caused by noise exposure, according to Verge, is a high frequency loss. ”That’s typically where clarity of speech is,” she says. Tinnitus, another type of hearing impairment and a specialization of Gulliver’s, also results from noise, including music. “You can get very little damage to hearing, but end up with tinnitus, constant, loud ringing in your ears that never, ever goes away. That can be very distressing,” says Gulliver.
Gulliver and Verge believe a spike on the graph showing music-player-related hearing loss lies ahead, unless awareness and preventive strategies don’t go into effect. The Nova Scotia Hearing and Speech Centre promotes awareness and prevention, along with treatment and testing for the injured, but they don’t advocate banning the players. The staff even visits elementary schools in HRM, where kids as young as grade four use these players, often abusing them. The risk for kids comes from the physiological fact that their ear canals are shorter, thus making the force of the music stronger.
But their young ears have not suffered the “cumulative” impact of loud music over time. So, “you’re not going to see a lot of young kids now. You’re going to see them 10 to 15 years from now,” Gulliver says.
At the Dalplex, Lambert uses the
earmuff—or supra-aural, as the experts call them—headphones. Conway uses the earbud style, the ones you place right in the ear’s opening; the ones that are receiving the majority of the negative press.
Gulliver and Verge simply want people to know these headphones sit closer to the eardrum, thus requiring a lower volume setting. Regardless of headphone model, the audiologists suggest resting your ears. Gulliver and Verge also advise limiting volume to a setting of 60 percent, or six, of the maximum volume setting on your digital player, as well as only using it at that sound level for no more than an hour a day. But each manufacturer calibrates its players’ settings differently. Remember, we’re not just talking iPods here. Establishing the 60 percent mark, and what constitutes peaks into potentially harmful levels, become difficult.
“What they should have are standards with each one saying this is what the peak is —this is our guideline for what it should go to before damage , the lengths of time you should listen to it,” Verge says. And while there are warnings on some packaging and headphones from high-end manufacturers such as Bose that cut down on background noise—decreasing the need to turn the music up—they’re not yet industry standard.
So it comes down to your own responsibility when it comes to music and your ears. A useful question in assessing the risk and response: Why the need to crank it to 11?
According to J Lapointe, who runs Archive Mastering in Dartmouth, playing loud music is a “natural” tendency. “It really comes down to the added sensation of physically feeling the music hit you, especially the low frequencies—hence the popularity of big car subwoofers, or all those portable stereos with X-BASS or MAXXBASS enhancements.”
But hearing well is “absolutely critical to my job,” says Lapointe, who’s mastered—a final step in preparing a recording for pressing onto CD—albums by countless artists, from Buck 65 to Contrived to Holy Shroud to Heavy Blinkers.
He takes precautions. “In the studio I run an SPL meter at all times to monitor the level of the speakers, just to make sure things are within safe limits,” LaPointe reveals. “I also keep a fresh supply of earplugs around for visiting musicians using the recording studio here.”
Annabel Cohen, professor of psychology at University of Prince Edward Island and adjunct professor at Dalhousie, sums it up this way: Your brain likes music. “Music has been shown to activate brain reward pathways, the same pathways activated by opiates and food,” she explains by email. “More food and more opiates may mean more pleasure, so more music might mean the same thing.”
But, Cohen says, “Neurons get tired. After they are stimulated they need time to recover.” She adds: “We have only one brain and it is limited in the number of things it can present to consciousness at one time. Music can take precedence over the pain of exercise, the pain in the dentist’s chair, the boring nature of housework.”
If a workout is good for your body, then look at turning down the tunes as good for your brain and ears. And when your hand goes for the volume dial, think of the symbolic blades of grass, standing straight and healthy, letting you hear the world.