Noise Cancelling Headphones, Explained

Active noise cancelling, or ANC, uses tiny microphones to listen to the sound around you and plays an inverted copy of it through the speakers. The two waves cancel out, and the steady drone of an engine or air conditioner fades away.

What ANC is good at, and what it isn't

ANC is excellent at low, constant sounds: plane cabins, trains, office hum. It is less effective against sudden, high-pitched noises like voices or a dropped plate. That is where passive isolation, the physical seal of an ear cushion or ear tip, does the work.

Adaptive and transparency modes

• Adaptive ANC samples your surroundings many times a second and adjusts strength automatically.
• Transparency mode pipes outside sound in, so you can hear announcements or a colleague without taking the headphones off.
• Wind reduction lowers the rumble you hear outdoors on breezy days.

Over-ear or earbuds?

Over-ear headphones usually cancel more noise, last longer on a charge and sound bigger. Earbuds fit in a pocket, stay put during workouts and are easier to sleep in. Many people end up with both: over-ears for travel and focus, earbuds for the gym and the commute.

Specs worth checking

• Battery life with ANC switched on, not just the headline figure.
• Multipoint Bluetooth, if you switch between a laptop and a phone.
• Codec support: AAC for iPhone, LDAC or aptX for higher-quality Android streaming.
• Weight, if you plan to wear them for hours at a time.