Testing the Sound Barriers Aboard a Loud Jet

Have you flown on any long flights lately? I said, have you flown on any long flights lately? It’s loud inside a jetliner: 80 to 95 decibels, depending on the plane and on where you sit. That’s as loud as a power mower--and it doesn’t even include the crying kids.

After a few hours in the noisy skies, it’s hard to hear yourself think--unless you’ve brought a pair of noise-canceling headphones along for the ride. I tested some noise-canceling headphones on a recent trip, and I’ll never travel without them again. Not only do the best noise-canceling headphones greatly diminish the in-flight roar, but they also sound far superior to the cheesy headphones that accompany most portable music players.

All noise-canceling headphones operate similarly. Inside each ear cup, a microphone listens for continuous low-frequency noise--exactly the kind of racket that a metal tube makes as it hurtles through the air at 600 mph.

The signal from these microphones is fed into circuitry that generates an equal but opposite sound, thus eliminating much of the noise before it reaches your eardrums. The process is roughly akin to putting a negative image on top of its positive counterpart: The two cancel out each other.

If you want to guarantee that you’ll be searched by airport security, stash three sets of headphones in your carry-on bag. That’s what I did in the course of testing Panasonic’s $49 RP-HC70, Sony Corp.’s $199 NDR-NC20, and Bose Corp.’s $299 QuietComfort.

When I told a Bose public relations person that I was planning to compare noise-canceling headphones, she declined to send a loaner unit, citing a company policy against participating in comparison reviews. So I bought a set of QuietComfort headphones from the Bose Web site, figuring I might take advantage of the company’s 30-day, money-back guarantee and return the headphones.

They’re not going back. The QuietComfort headphones aren’t cheap, but they out-quiet the competition by a wide margin. Snug their supple ear cups into place and flick a switch, and the in-flight roar subsides to a subtle hiss.

You can still hear the crying kids, but the din recedes to well below headache levels.

And you do get a lot for the money. The headphones sound fabulous and are far more comfortable than the Sony and Panasonic headsets. And they include a padded carrying case that has room for a portable music player and even a few compact discs. Also included are adapters for connecting to stereos, TVs and airliner armrest jacks.

And the Sony and Panasonic headphones? Both reduced the roar only marginally, and Sony’s did a better job than Panasonic’s. Part of that may be due to superior electronics, but another factor is that Sony’s headphones, like Bose’s, use a closed design: They surround your ears with a padded ear cup that helps isolate outside sound.

At home, I tested the headsets while using a treadmill and while standing in front of a kitchen vent fan that does an uncanny imitation of a DC-9. Again, neither Panasonic nor Sony could match Bose’s noise-canceling talents, fidelity and comfort.

Because noise-canceling headphones contain electronics of their own, they require batteries. The Panasonic and Sony headphones each use one AAA battery, and the Bose QuietComfort requires two. And it’s worth noting that the Bose headset operates only when its batteries have juice. By comparison, the Sony and Panasonic units can operate as passive headphones: Switch them off or drain the batteries, and they still work, albeit with no noise reduction.

Sony’s and Panasonic’s headphones also are more compact than the QuietComfort headset; both have a fold-up design that takes up less space in your luggage. But if you have room in your carry-on bag--and in your budget--buy the Bose.