Pioneer SE-NC31C

Took the Pioneer SE-NC31C earphones with active noise-cancellation for a test drive on the daily commute. Happy to report that it works as advertised. Instead of simply blocking out everything, it merely cancels out (up to 90% of) the constant noise. That means it doesn't really eliminate the engine revs, but the constant bus hum is gone. Great when you still need to be aware of your surroundings. Audio quality is pretty good but not as good as my Brainwavz M4 IEMs. In terms of controls, there is an on/off switch to enable/disable the noice-cancelling feature. There's also a monitor button to temporarily turn off the audio, so you can "monitor" your surroundings. One AAA battery is supposedly good for 120 hours of noise-free audio.