Silence is golden, and the purchase price can be as little as $40.
I'm talking about noise-canceling headphones, originally developed to mask whining jet engines and sold at prices only first-class airline passengers could afford.
Not that you should be oversold by the term "noise-canceling." What you really get is a reduction in background noise, not complete blocking of external sound. That makes it easier to hear what's coming through the headphone wire -- whether that's music, a radio station or the soundtrack of a movie.
Still, there's real value in noise-canceling technology. Ferocious competition in the consumer electronics business has worked its inevitable magic, and decent-quality noise-canceling headphones now are widely available for $40 to $80.
These low prices open up lots of new settings for noise-canceling headphones: Students riding school buses, commuters on subway trains, office workers chained in cubicles underneath ventilation ducts, even someone listening to a peaceful lullaby in bed during a heat wave as an air conditioner rumbles.
I just finished a homemade test comparing low-end and high-end models, plugging one after another into my Apple iPod digital music player. At the low end, I put my ears inside the $59 Koss QZ Pro and the $69 RCA HPNC300. At the high end, I tried the $299 Bose Quiet Comfort 2.
The good news for those of us who fly coach: The Koss QZ Pro and the RCA HPNC300 did a respectable job in canceling household noise, including my microwave oven, clothes dryer and in-room air conditioner. The Bose Quiet Comfort 2 did better, in both noise-cancellation and quality of music reproduction, but not by much. The low end, at least to my admittedly tin ear, delivered almost all the performance for less than one-fourth the price.
How this works is both simple and complicated.
The simple part is the basic physics: Sound is a wave. If you create an equal and opposite wave, they cancel each other out.
The complicated part is cramming the hardware to pull off this trick into something as small as a pair of headphones. There must be a microphone to detect external noise and a tiny speaker, also called a transducer or driver, to make the anti-noise. A microprocessor chip has to make all the necessary calculations. And all these pieces must work together without distorting the music or movie dialogue you want to hear.
Early noise-canceling headphones required a bulky external box holding the electronics and batteries. Now, all but the tiniest in-ear models put everything into the headphones. Running time typically ranges from 20 hours to 40 hours on one or two AAA batteries.
For all the improvements, it's important to set realistic expectations before buying. Even the best noise-canceling headphones aren't miraculous. Steady, low-frequency sounds will be greatly diminished but not entirely eliminated. High-frequency sounds, such as squealing brakes, are less likely to be muffled. Irregular sounds, such as a loud talker in the next airline seat, won't be stopped. And overwhelmingly loud noises will still get through.
With that in mind, I think low-end noise-canceling headphones are a great deal for anyone who even occasionally wants peace and quiet in a loud world.
In addition to my tests at home, I took several airplane flights with the RCA HPNC300 headphones. The experience, at home and in the air, was always the same whenever I flipped the switch to start noise cancellation: Music seemed to move closer to my ears, while outside noise seemed to move away. This made the listening process much more relaxing, because my brain was no longer working to filter out unwelcome rumbles and whines.
There is now a huge selection of noise-canceling headphones in the $40 to $80 range. Big-name manufacturers, in addition to Koss and RCA, include Aiwa, Maxell, Panasonic, Philips and Sony. While recommending inexpensive models, I'm in no way disrespecting more expensive models. You get more if you pay more, both in audio and noise-canceling quality.