These noise cancelers aren't as compact as the AKGs, but they provide excellent noise reduction, with 20- to 30-dB reductions throughout most of the range. Passive noise reduction is effective in the higher end, and the active circuit does a good job down low. The frequency response leaves something to be desired; it's weak in both the bass and the high end. But the design is innovative: As with the category-leading Bose Quiet Comfort 2, the electronics and single triple-A battery are in one earpiece, and the other holds the retractable cord (up to 5 feet). The NC100s fold compactly and come with a travel bag and a two-prong airline adapter. They're plenty loud, with 105-dB peaks.