Any headphones have to deliver in the comfort department, and both manufacturers score well here. The PXC-350s encase your lugholes with well-padded earpieces, and the headbands is nicely padded too. Some headphones of this type can feel a little loose and move around with even a small amount of head movement. We aren't saying you can go jogging in the PXC-350s, but they are robust enough to stand up to normal walking pace and are very comfortable whether at rest or on the move.

A case to answer

The Denon AH-NC732s are also an over-ear set, but weigh much less: 160g to 230g. They're also comfortable, but we found the much snugger fit of the earpieces, which are quite a bit smaller that their rivals', were less comfortable over long periods of wear.

Sennheiser loves to point to out how it's a pioneer of noise-cancelling technology, originally developing the system for airline pilots - BA and Lufthansa use Sennheiser 'phones. The PXC-350s include patented duofol diaphragms which are designed to prevent unwanted resonances and promote crisp, crystal-clear sound, the company says.

Sennheiser's NoiseGuard technology actively neutralises unwanted environmental noise buy using a tiny microphone mounted on the outside of the headphone to pick up ambient sound. A processor flips this sound upside down and them pumps it out through the 'phones. Incoming external noises and the reverse version of the same meet and cancel each other out.

Denon crams them in - and there's room for other items too

Denon’s noise-canceling phones neutralise unwanted sound in the same way and general playback quality is claimed to be improved by a specially designed "Acoustic Optimiser" which Denon says ensures dynamic sound and deep rich bass response by adjusting the sound pressure balance in front of and behind the diaphragm.