What are they? Noise-reducing headphones
What do they do? Like earmuffs, they make loud environments quieter, but they do it electronically and are a lot more effective. Applying technology developed for use by commercial and military pilots, built-in microphones measure the level and type of background noise, then microcircuitry generates an 'opposite' signal that cancels out the unwanted sounds - making long train journeys and flights, in the cockpit or the cabin, a far more relaxing experience. When you don't want tranquility, plug them into your Walkman and they become top-of-the-range hi-fi headphones.
What's the competition? Earplugs - wax, rubber or cotton wool - are cheap but of limited effectiveness, and they can be uncomfortable to use. You can't listen to the in-flight movie in full stereo on them either. For the seasoned long-haul traveller, these cans are the only choice.
Where can I get them? They are available now from Bose for pounds 245, including VAT.