While the world is full of enjoyable sounds, there are some that are better to block out, particularly if you wish to listen to music or a film. For many, trains, buses and airplanes are simply too loud for them to relax and enjoy the journey. That’s where noise cancelling headphones come in.
But how do they work? The first thing to understand is that there’s a difference between “passive noise cancellation,” which is often used to describe noise isolating headphones and noise cancelling headphones. Passive noise cancellation blocks out noise by creating a seal between your ear and the headphone. Earbuds are designed to fit snugly in your ear, while over-ear models have thickly padded cups designed to block out as much outside noise as possible.
Noise cancelling headphones, on the other hand, call upon technology to block out ambient sounds. They use digital signal processing (DSP) technology, which cancels out the sound waves from noise. This means that these headphones have an internal microphone and audio processor that “listens” to the sound around you and produces a noise with a mirrored sound wave so that they cancel each other out.
Environments with a high level of background noise, such as airplanes, trains or open offices are perfectly suited for noise cancelling headphones. Low, steady sounds are easy to cancel out, though higher frequency, and brief sounds are far more challenging. As a result, you may still hear voices, slamming doors and noises like that, but they will be significantly muffled.
Noise cancellation headphones are great for getting some peace and quiet or listening to music without external interference. However, if you need to hear your surroundings for safety, such as when you’re on a platform waiting for an announcement for an arriving train orcrossing roads, you may want to take them off.
In Short: If you’ve ever wondered what the difference between passive and active noise cancellation is, and how it benefits you, we dip into the topic here.