Panasonic RP-HC30-K

Noise-cancelling headphones work by creating "anti-noise" that exactly counterbalances external sounds at the ear.  While unable to cope with non-repetitive sounds, they do a good job of reducing the constant drone in an airliner cabin or the hum of a room air conditioner or computer fan.

  Noise-cancelling headphones began as an expensive, bulky laboratory concept but has been boiled down to diminutive earbuds in the form of Panasonic's RP-HC30-K.  A mid-range offering that stands out as the only earbuds in the RP-HC line, these tiny noise-cancellers offer up to 50 hours of operation on a single AAA alkaline battery.  The neodymium-backed 0.42" drivers respond to frequencies from 8 Hz to 22 KHz, and can handle up to 50 mW of power.  A monitor switch allows a quick check on what's going on around you.  For travel use, the RP-HC30-K comes with a convenient carrying case and even an aircraft adapter.