I live in New York, N.Y., a place that's never quiet. It's not just traffic noise, people noise, music in the streets, or the cumulative effect of all the buildings' air conditioning exhaust fans. There's a low, deep hum that always throbs to the beat of a city of 8 million people.
Judging by the number of folks wearing headphones on the subway, I'm not the only one using music to mask the noise. The subway may be one of the loudest places you can be in this town, but restaurants can get painfully loud, especially when they play music over their sound systems, which makes the customers talk louder and louder. It seems like the later in the night you go to eat, the louder the interior noise level will be. Bars are even worse.
True silence is hard to come by, and when you're in a fairly quiet building or office you start to hear just how loud air conditioning can be, or the buzz of florescent lights. Parks have people, and people always make noise, and when there are just a few people around, birds, animals, and insects might stir up a racket. You think I'm joking? A few years ago while visiting some friends in Connecticut I couldn't believe how loud the cicadas could get late at night (some register more than 100 decibels when singing). That's louder than a lawn mower! So it's not just city folk who have to worry about exposure to loud sounds.
Noise-canceling headphones can hush the din, but I prefer the sound of noise-isolating in-ear headphones. Noise-canceling models use battery-powered electronics to cancel noise, but I find most noise-canceling models don't sound all that good. Noise-isolating models don't use electronics and therefore don't need batteries. I'm a fan of Etymotic and Monster in-ear headphones, and custom molded to your ear canal models from JH Audio, Ultimate Ears, and Westone offer even better noise isolation, definitely superior to noise-canceling headphones, that's for sure. Custom molded headphone prices start around $400.
Looking for something cheaper? A set of E.A.R. foam earplugs is the most cost-effective way to fend off the racket. I always have a pair of Etymotic Ety Plugs in my pocket, and stick 'em in my ears when attending amplified concerts and movie theaters. Ety Plugs turn down the noise but don't muffle voices, environmental sounds, or music. They "sound" better than foam-type ear plugs.
And if you're concerned about your hearing, or what's left of it, check out this do-it-yourself hearing test.