Noise-cancelling headphones are a great way to filter out ambient distractions when you’re listening music and audio books, and Denon reckons that its latest set can reduce external noise “by about 99%”.
The AH-NC800 Dual Noise Cancelling headphones have a closed, over-the-ear design to reduce sound leakage, with leather ear pads for “superb comfort” — though this sounds like a recipe for sweat if your jugs are going to be pressed against a bit of a cow for long periods.
Noise-cancelling headphones work by using a microphone to sample ambient noise (anything not coming from inside the headphones, in other words) and inverting its waveform. When played back through the headphones, this all but cancels out the external noise, though it’s most effective on constant, low frequency rumbles like car and jet engines.
The ‘dual noise cancelling’ technology Denon uses for the AH-NC800s uses two microphones — one outside the headphones and one inside the ear pads themselves, presumably to pick up any muffled noise that makes it through the padding.
The headphones run for 40 hours on one AA battery — active noise cancelling requires a power source — and they revert to standard headphones once the juice runs out.
The cheapest online price for the AH-NC800s at the moment is £249, which is on the expensive side compared to headphones from other manufacturers, but it's perhaps worth it if Denon’s 99% noise cancellation claim is accurate.