Noise-cancelling headphones are one of the great, simple pleasures of a modern world. Between the hiss of noise pollution, smartphones burping for attention and the roar of constant traffic, a break of silence is a rare joy.
The Audio ATH-ANC9 headphones deliver this silence in three flavours: Airplane, Office and Study modes, each offering a slightly varied effect. According to Audio Technica, Airplane mode cuts 95 per cent of environmental noise at 200Hz, Office cuts 95 per cent at 300Hz and study cuts 85 per cent at 200Hz. These modes aim to target the sorts of noises heard in this different situations; Airplane mode targets low frequencies to cut the rumble on trains, planes and automobiles, for example.
Four microphones are used to sample ambient noise and create the effect, with two mics in each cup. Our ears aren't fantastic at differentiating between audio frequencies, but they do report an impressive reduction in ambient sound when the noise cancellation is active. At work, the chatter of the office is cut to a barely audible murmur -- which is both a blessing and a curse, depending on the office environment. On a busy bus, the effect is more pronounced and definitely welcomed. The roar of the engine is dramatically lessened, and the chatter of business people on phones and lunatics communing with imaginary friends or God is all but silenced.
The catch is that the four microphones need power, and, unlike other noise-cancelling headphones we've reviewed, the ANC9s use a replaceable AAA battery, rather than a rechargeable lithium-ion battery. Audio Technica rates the battery at 30 hours of golden silence, which equates to one night of forgetting to switch the power off on these cans -- a mistake we made on the day we received them for review. In some situations, replaceable batteries are ideal, especially if you are travelling a lot and don't want to have to keep remembering to plug these headphones in. But we'd argue that most users will find this far more cumbersome than a rechargeable solution.