Ever since Apple was sued by a Louisiana man claiming his iPod caused irreparable hearing loss, I’ve been scratching my head about vendors’ responsibility to prevent hearing loss versus individuals’ responsibility to take care of their own health. After all, hadn’t Apple already published a warning that playing your iPod too loud could be bad for your hearing? And how is an iPod worse than a typical city street, an airplane cabin, a car, a nightclub, and most work environments, elementary schools and hospitals — all of which often expose you to more then enough noise to harm your hearing? Then, when Apple provided a volume limit setting for the iPod, it seemed like the company was going above and beyond its obligations to the public. But I finally heard from a knowledgeable source that I trust on the issue, and unfortunately the news isn’t good. Dr. Brent Edwards, head of the Starkey Hearing Research Center, says in his Innovation Science blog that “Apple’s response provides so little guidance on how to set the limit that it is near useless to concerned parents of children who use iPods or to concerned iPod listeners.”
Dr. Edwards makes the point that if you don’t let people know how much is too much, there is no way they’ll set their iPods to safe levels. Edwards cites an excellent article in the March issue of Hearing Review to make the point that even experts are often surprised at just how little usage can be too much of a good thing. When it comes to hearing loss, exposure to noise is cumulative — your ears can stand loud noises of short duration, but long exposure to what most people would consider moderate levels of sound in their earbuds can cause permanent damage. Based on a time-weighted-average (TWA) measure of potential hearing loss at different decibel levels over different periods of time, the article’s author shows that someone using an iPod nano would be risking permanent hearing loss after only 23 minutes of use with the volume set at 80 percent of its maximum, and with the volume set at 100 percent they would potentially suffer irreparable damage after only one minute. He also notes that ear buds inserted deeper into the ear can cause even more damage because they effectively increase the decible levels of sound hitting the eardrum.
Edwards says Apple could do more to help prevent risk of hearing loss among its iPod customers: “It does not ask whether the person is listening with insert earphones or earbuds–Apple’s software should tell people that limits should be set lower if inserts are used. Secondly, they don’t give any guidance at all as to how long the iPod can be used at that maximum setting. Right now, providing the volume control limit ability is like being given medicine with no guidance on dosage or how often to repeat a dose. If Apple wanted to, they could design firmware that would embed a sound level meter inside the iPod and beep when the daily safe limit of sound exposure has been reached.” Finally, Edwards recommends that you not listen to your iPod at more than 60 percent of maximum volume for any extended time. And if you’re in a noisy place, think twice about turning up the volume on your iPod and drown out the exterior sound. It’s far too easy to damage your hearing without even knowing it.