by Caitlin Ohama-Darcus
A well-known English proverb says “you are what you eat.” I, on other hand, believe that you are what you hear.
Emitted from sources such as machinery and portable music players, traveling sound waves induce small changes in air pressure, which in turn cause the vibration of tiny hair cells in the ear. The bending of these tiny hair cells causes auditory receptors to transmit nerve impulses to the brain. These nerve impulses are then interpreted in the brain as sound.
Damage to the ear, which in turn results in hearing loss, occurs when a person has been exposed to loud sounds over extended periods of time. Not surprisingly, the risk of hearing loss increases as volume and listening time increase. WorkSafe BC, the Worker’s Compensation Board of British Columbia, sets the Daily Noise Exposure Level for noise at 85 dB based on 8 hours of sustained listening. The Peak Workplace Sound Level is set at 140 dB.
Now this large range of numbers might not mean a single thing to you, but for your ears these numbers certainly do matter. The problem is, today more than ever people are being unknowingly exposed to dangerously loud sounds, very often at their own risk.
Consider, for example, a typical day’s ride on the bus. Look around and what do you see? Lots of people, yes… but what are they doing? Reading, working, sleeping? Perhaps. What about listening to music? Well, that almost seems like a silly question to ask. Just look around the bus and you’ll see—there are a lot more people with headphones in their ears than there are those without. In fact, it’s not unusual these days to be riding public transportation and listening to music— not your own, that is, but the blasting tunes of others.
In the 1980s, the Walkman was the required social accessory for teenagers. Today, along with cell phones, it is the iPod. And teenagers are no longer the only ones plugging in and tuning out. As of April 2007, Apple’s iPod sales reached an estimated 100 million units worldwide—sales to consumers that include teenagers, adults, seniors and children. With their longer battery lives and increasingly larger music capacities, iPods have never been used so extensively.
Unfortunately, along with this ever-growing love for portable music comes the risk of serious hearing damage. As part of a university measurement project that I designed and undertook, present day iPod use (depending on what volume you listen to your music at) was linked to the potential for hearing loss.
Without elaborating on any of its more gory scientific details, the findings of my experiment simply reinforce what to many may consider to be common sense. Listen to your iPod for just fifteen minutes with volume set at 80% (the iPod volume toggle ranges from 0 to 100%), and you’re at risk of seriously damaging your ears. Listen to your iPod for one hour with volume set at just 70% and the sound intensity emitted surpasses WorkSafe BC’s noise exposure levels.
Unfortunately, as with most things common and most things sensible, healthy ideas don’t always translate into ear-friendly actions. So what can you do to save help save your ears (but still enjoy listening to music on the bus)? First of all, only listen to your music in the 50 to 70% volume range. If you’re in a noisy environment and crank up the volume just to drown out the surrounding noise, remember that the tiny hair cells in your ear are only working harder as a result. As with any machine, the harder it works the more likely it is to get worn out or break down. A second way to preserve your hearing is by setting the built-in volume limiter on your portable music device to an appropriate level. Third generation iPods (unlike older iPod models) now include a built-in volume limiter that can be custom set by the user. Instructions to set a maximum volume level are available on the Apple website.
The moral of the article is this: listen to your iPod at sensible volume levels, and listen to your iPod in moderation. Your ears are worth it.