Sony ships its MDR-NC500D headphones on March 21, touted as groundbreaking technology. The company sent us a pair just before we hopped on a plane to the annual Sony Open House in Las Vegas, inviting us to take a listen to the $400 cans as we winded our way toward Sleazetown. Ho hum, we said. Yet another pair of noise-canceling headphones? Yes, but these phones really are different, and just about knocked our socks off as soon as we took to the air.

Why do you feel so tired after a long flight? Seems odd since you’ve been just sitting there, nearly motionless. Part of that fatigue you’re feeling has to do with the constant and relentless noise you must endure throughout the journey. The engines make enough noise themselves, but the loudest noise is caused by the air rushing alongside the fuselage at 520mph. A lot of that noise is down in the low frequencies, around the 120Hz range, and Sony claims these NC500Ds can eliminate 99% of the constant noise in that range. Hit Continue and see if they can really do that.

Sony’s taking a novel approach to eliminating noise. I talked with Naotaka Tsunoda, designer of the headphones, who came to Las Vegas from Tokyo to show off his new creation. “The artificial intelligence detects how the environment sounds,” he says. “Then it chooses one of three noise 'situations' according to the kind of sounds in your environment.” Push a button on the right earcup, and the smart earphones listen to the ambient sounds for three seconds, and then suddenly there’s sweet silence. You can also manually set the noise-reduction curve, specially calibrated for either airplanes, buses/trains, or an office environment.

Not only are these the quietest headphones I’ve ever heard, they’re also among the most comfortable I’ve ever placed on my head. They weigh next to nothing, and I wore them for four hours with no discomfort whatsoever. I just didn’t want to take them off. They don’t squeeze your head too hard, but hug it just enough to seal away all that racket. One reason for that wearability is their extraordinary light weight. How did they get them so light? Says Tsunoda, “We made the headband out of aluminum alloy, and the earcups are magnesium. Overall, they’re half the weight of our other headphones that are the same size.” They’re a feather-light 195 grams (6.9 oz), and feel just right. We like.

The product includes an elaborate carrying case that’s too big. I like to travel light, so I ditched the case and slid the phones into my carry-on. They lie flat, taking up hardly any room in my crowded travel bag. Before you hit the road, it’s a good idea to charge up the lithium battery inside the earcup, which is said to last 16 hours on a charge, long enough for the longest flight. If that’s not going to last long enough, there’s also an outboard auxiliary power unit into which you can place a couple of AA batteries, giving you 12 more hours of listening bliss.

Playing rock and roll music over the phones via my iPhone, I couldn’t turn the volume all the way up without running into trouble — the bass started popping. But taking it down a couple of notches, I could hear the sweet spot. After all, the idea here isn’t to see how loud the music can go — it’s how soft can you listen to it amid that blast of rushing air on an airplane. And with all that noise gone, I could hear some clean, shimmering highs, and bass was powerful and supportive without being boomy. Aside from their stellar noise reduction capabilities, the sound quality of these earphones was remarkable.

Usually, if you want to hear music noise-free on an airplane, you need to turn it up to extraordinary volume levels. But what if you’re listening to a quiet, soothing piece? I tried some Bach guitar music and turned it down as low as I could, just above the noise floor. Wow. The noise was barely audible, and I was listening to some really quiet music. This is something I could get used to.

When the pilot starts talking, there is a button you can push called “monitor” that lets you hear outside sounds. As long as you hold it, the outside world with its loud noises, comes into your ears. Let go, and back you go to that serene silence, where the only noise you can hear is a faint hiss.

Then there are the tiny details that are also a delight, such as the aqua, pink and orange pilot lights, attractive piano black finish and adapter-free iPhone compatibility. Listening to them, I was so impressed, I wanted to grab someone walking by and say, “Listen to this!”

I’ve heard the Bose noise-canceling phones of different generations, and the Plane Quiet models, too, and my ears tell me these Sony NC500Ds are the best yet, taking noise down to a nearly indistinguishable level. If you’re a traveler, you’ll feel a lot less fatigued after a flight wearing these, even if you’re not listening to music at all. I’d say the world opened up by them is well worth their $400 cost of admission.

Sony Style