I review noise-cancelling headphones for a living, and this simple trick can boost sound quality and battery life

Sony WH-1000XM5 noise-cancelling controls
(Image credit: What Hi-Fi?)

Noise-cancelling headphones are great for anyone wanting to cut out the drone of daily life, the rumble of road traffic, the noise inside an aircraft cabin or that one person who insists on holding a voice call in the middle of a busy office.

Our list of the best noise-cancelling headphones only contains five-star pairs that have been tried and tested by our expert review team and have been found to perform well across the board. And there are some fantastic options in there from all the usual suspects, including Apple, Bose and Sony.

But over the years I’ve tested multiple pairs and one interesting thing I’ve noticed is that a simple trick can make some ANC headphones perform even better. And, generously, I'm willing to share it...

Simple yet very effective

Wireless noise-cancelling headphones: Sennheiser Momentum 4 Wireless

(Image credit: Sennheiser)

It’s a very simple step, but it can have a transformative effect on sound quality too. Another byproduct is that it can also give battery life a boost.

So what’s the secret? Well, it’s as straightforward as turning noise-cancelling off completely. Yes, that’s it. No secret combination of button presses. No smoke and mirrors.

You see, chances are you probably don’t need noise-cancelling on all the time. If your headphones provide good noise isolation from either the earpads on your over-ear headphones or the tips of your wireless earbuds, ‘ANC On’ doesn’t always need to be their default position.

Think twice before you automatically turn ANC on and the positive effects can be twofold. The most obvious benefit here is it can be a saviour for battery life. If you’re running low and want to preserve your Bluetooth connection for an extra hour or so, powering down your ANC will help. Your wireless connection will still be affecting battery life, but the extra power demands that the noise-cancelling tech inside the headphones puts on the rechargeable battery won’t be there.

And battery life isn't the only area that can be improved upon.

There can be a bigger benefit

Bose QuietComfort Earbuds II vs Apple AirPods Pro 2

(Image credit: Future)

You see, active noise-cancelling brings with it challenges in terms of audio engineering and in my experience it can affect sound quality.

ANC adds an extra layer of complex processing where the built-in mics work with the noise-cancelling tech built into the headphones to decide which frequencies to filter out.

During testing, I’ve noticed multiple occasions where switching ANC on automatically results in a shift in the balance of the sound you’re hearing. You can sometimes hear an artificial boost in both low and high frequencies that manufacturers have built into the audio processing which can affect timing, i.e. the precision and natural flow of the music, and also result in a loss of detail and subtlety. I’m not saying every pair of noise-cancelling headphones suffers from this problem, but in the worst examples, ANC seems to flatten the dynamics and the shape of the music.

It doesn't only affect cheaper pairs either. During our review of the first-generation Apple AirPods Pro, we noticed that turning ANC off resulted in a “slightly tonally richer and rhythmically crisper performance”.

But, I have found over the years the best noise-cancelling pairs are also the most consistent whether you’re listening with ANC turned on or off, or at least they do a better job of masking those frequency boosts.

Why not try it with your noise-cancelling headphones and see if you can hear a difference?


How active noise-cancelling headphones work: the technology behind ANC

Our pick of the best cheap noise-cancelling headphones

How to choose the right pair of headphones

Andy Madden

Andy is Deputy Editor of What Hi-Fi? and a consumer electronics journalist with nearly 20 years of experience writing news, reviews and features. Over the years he's also contributed to a number of other outlets, including The Sunday Times, the BBC, Stuff, and BA High Life Magazine. Premium wireless earbuds are his passion but he's also keen on car tech and in-car audio systems and can often be found cruising the countryside testing the latest set-ups. In his spare time Andy is a keen golfer and gamer.