Do You Hear What I Hear?

I'd always assumed my hearing must be damaged, at least a little bit. I mean, everyone told me it would be.

I've been told for years that all kinds of things that I love doing - wearing headphones, listening to loud music in my car and attending live shows - would likely damage my hearing. The thinking went that if you listen to a lot of loud stuff, you lower your auditory sensitivity. That seems reasonable. But I loved rock music, I was young, and I didn't care. Who needs hearing, right?

Then a couple years ago, a bunch of online tests cropped up that played different frequencies and based your 'hearing age' on what the highest one you could hear was (here is a good one). I was pretty surprised to find that I top out at about 17 khz. That's supposed to be the sweet spot for teenagers, but I'm pushing thirty. Meanwhile, my parents, aficionados of classical music and Protestant hymns, could only hear much, much lower sounds.

My punk rawk plan to sacrifice my hearing on the altar of metal seems to have been thwarted.

What gives? Wired reports on a new study that shows that hearing loss is diminshing across generations:

Despite all the Walkmen, boomboxes, 8-tracks, iPods and Bluetooth headsets that have delivered raucous noise to the ears of Baby Boomers, hearing loss appears to be declining among adults.

This counterintuitive finding from the first study of long-term changes in hearing loss is that for every five years a man or woman was born later in the 20th century, their chance of having hearing impairment dropped 13 percent and 6 percent, respectively.

A key suggestion of the report is that other, positive changes in the last 50 years — reduced noise levels at work and better overall health — are more important than the rise of headphones and other entertainingly noisy new products.

Here's another thought I'll throw at you: there's a difference between music and noise. Noises have irregular, rapidly changing wavelengths, while most music has more regular and predictable wavelengths. Music that follows the western scale typically has wavelengths that occur at regular intervals - 1/2, 1/3, or 1/5 the original wavelength. Cacophonous, unpredictable noise or discordant overlapping between unrelated frequencies is relatively rare, even in genres like Black Metal.

Simple experience tells me that loud noises are much harder on your ears than loud music. In the twenty-first century, most of us have traded insulated cubicles for the noisy factory floor. The soft whirr of a computer fan and the buzz of fluorescent lighting is far easier on our ears than the clank and grind of machinery or the crash of a pallet full of raw material hitting the ground.

Meanwhile, that stuff blaring out of my earbuds may be loud, but it's not noise; at least, not to my brain, which is really the only thing that counts.