Noise-cancelling headphones tend to be big and bulky, but you might find the travel-friendly ATH-ANC23 a better fit for your pocket and your budget.
Typically noise-cancelling headphones are large, closed-back cans which fit over your ears, such as the $699 Sennheiser PXC 450 headphones which I carry in my travel bag. They do a great job and offer excellent sound quality, but you're paying a premium and they're rather cumbersome to carry around. Their bulk can also get in the way if you're trying to rest on a plane with your head on the side during a long-haul flight. They're comfortable on your head but can get sweaty after a while.
Audio-Technica has taken a different approach with its $99 ATH-ANC23 QuietPoint in-ear noise-cancelling earbuds. Some people hate having earbuds crammed deep into their ears, and that's understandable, but it's certainly worth weighing up the ANC23 against the competition. They're rated to block 90 percent of noise, but results will vary depending on your surroundings. Noise-cancelling works best with constant drones such as engine noises, so I tested them on a Boeing 737 800. Noise-cancelling doesn't cope as well with spasmodic noise such as nearby conversations and if you're expecting a cone of silence you'll be disappointed.
For only $99 you're entitled to expect very little from these earbuds -- Sennheiser's own noise-cancelling CXC 700 earbuds sell for around double the price. But the $99 Audio-Technica earbuds can hold their head high, even when compared to the top of the range PXC 450 Sennheiser headphones. They seem to block slightly different frequencies and the Audio-Technicas' background hum is at a slightly higher pitch. The Sennheisers' over-the-ear design also does a slightly better job of blocking out background conversation -- but again don't expect the cone of silence. Switching between them during a flight, I'd say the Sennheisers do a slightly better job of noise-cancelling and are a little more comfortable, but there's not a lot in it.
The benefit of the Audio-Technica earbuds is that they slip into a tiny cloth carry case which fits in your pocket, whereas the big Sennheiser cans come in a hard case that's larger than a DVD case and several times thicker. The Audio-Technica earbuds also feature a lapel clip with a power switch and volume control, but there's no mic for making hands-free phone calls. They can still function as normal headphones when the power is off, which is handy for day to day use, although engaging the noise-cancelling also boosts the sound.
Audio-Technica includes a choice of rubber or foam earbuds -- the former do a slightly better job of blocking out background noise, like earplugs, but the latter are more comfortable. You get two sets of each, allowing for different sized ear canals, plus you also get a dual-prong aeroplane adaptor.
Unfortunately the Audio-Technica earbuds fall just short when it comes to sound quality. They're a little brash compared to the Sennheiser cans and the bass is not quite as rich, but that's understandable given the price difference. If you're not anal about sound quality you'll be perfectly happy with these Audio-Technicas, but audiophiles could be underwhelmed.
At $99 it's pretty hard to find fault with these Audio-Technica earbuds -- I've tested more expensive noise-cancelling headsets which sounded far worse. If you're a well-heeled jet setter then you'll probably lean towards something like Sennheiser cans, but these earbuds could still make a handy second pair -- especially when you're resting with your head on the side and can't get comfortable wearing the bulky cans. If you're an occasional traveller who doesn't have the carry on space or the cash to consider top-shelf bulky cans, definitely put Audio-Technica's ATH-ANC23 on your shortlist.