Sony MDR-NC200D Digital Noise-Cancelling Headphones
Sony MDR-NC200D digital noise canceling headphones are unique in that they feature three tailored noise reduction settings (automatically chosen) for noise from airplanes, trains, and office environments. This is an on-the-ear design which means they don't seal the ears as well as over-the-ear phones. Nevertheless, the noise cancellation system works quite well. And, as a bonus, you can wear these with no cord attached and use the NC system to create a quiet space even when not listening to music.
Frequency response is listed as from 8 Hz to 23 KHz. The 40mm drivers deliver a sound that is a little on the crisp side with the upper mids and treble a bit hyped. This is especially noticeable with the noise cancellation on. If you like a very defined treble, these will be to your liking. The noise cancellation system uses a single AAA battery, with battery life rated at 22 hours, a bit on the low side. Unlike some other designs on the list, the MDR-NC200D works in passive mode so a dead battery doesn't end the listening. These lightweight headphones are a good choice if you don't have the budget for more costly headphones from Bose or Polk.