The New York Times' Adam Baer has an early look at Brookstone's SoundShield noise-canceling headphones. The big advantage these have is the price — about $150. And at just four ounces, they're also fairly light and compact for people averse to in-ear models (which tend to be more expensive anyway). The headphones work by first recording ambient sounds and then creating a digital mirror image of the noise, which causes the two waves to interfere and cancel each other out (the big foam ear cups also help in cutting out noise). Apparently, you'll get a noise reduction in the audible range of about 30 hertz to 10 kilohertz. They'll be on the market sometime next month.