Whether you're in the office, working from home, or just want to listen to some music on the bus, background noise can be an annoying interference. To help you keep your focus, many modern headsets and headphones include built-in noise cancellation. As the name suggests, this feature helps block out unwanted sounds from around you. That way, you can concentrate fully on the task at hand- or just enjoy a bit of peace and quiet!

How noise cancellation works

Noise cancelling headphones were first invented for use by pilots. On long flights, the constant hum of engines would quickly get on their nerves. To make their lives a bit more comfortable, they needed something to block this sound out. These early models did such a good job that they were soon put on the market for passengers, too. Over time, the feature became increasingly common in both headsets and headphones. Nowadays, virtually all models offer at least some level of noise cancellation.

There are two different types of noise cancelling headsets: active and passive. In practise, both do the same thing: block out sounds from around you. However, the way they work- and how effective they can be- is quite different.


Passive noise reduction or noise isolation

Most decent quality over-ear headphones and headsets offer some level of passive noise reduction, thanks to the materials used on the headphones themselves. These help to block out specific sound waves, particularly at higher frequencies. Circumaural headsets- those which completely cover the user's ears- are naturally the best for this purpose. By forming a seal around your ear, these headsets limit how much sound can get through. While they won't completely block out sounds from your surroundings, they do muffle them to an extent.

Some models are specifically designed to offer superior passive noise-cancelling. These circumaural models are made using multiple layers of a high-density sound-absorbing material, such as foam. This makes them slightly heavier than your typical headphones. But for the extra weight, they are able to block out sounds of about 15 - 20 decibels (dB). That may not be enough to block out the sounds of, say, a plane within the cabin, or a particularly loud colleague. For low-level background noise, though, these models can generally get the job done.


Active noise-cancelling

Headsets with active noise-cancelling take things up a level. As well as passive noise cancelling, they also actively erase lower-frequency sound waves. In this way, they offer a much higher amount of noise cancelling capabilities.

Active noise cancelling headsets use special digital signal processing (DSP) technology to actively cancel out low frequency sound waves from ambient noise. Using an internal microphone, these headsets listen to the sounds around you, and then play a contrasting sound. This process is known as "destructive interference". Since this contrasting sound is a 180-degree flip of the incoming sound, both are cancelled out- to the listener, there's nothing but sweet, sweet silence.

The downside of this is that active noise cancelling headsets tend to be a bit more expensive than their passive counterpart. On the other hand, they are typically much more well-built, offering superior sound quality as well as improved noise cancellation.

How effective is noise cancellation?

Just how effective these headsets are at cancelling out background noise will differ from one model to another. The best active noise cancelling headsets- such as those from Jabra- can effectively reduce overall noise by up to 45 dB. That means they can comfortably handle constant, ambient noise, including jet engines, air conditioning, and background chatter. They don't cope so well with sudden sounds, such as a door slamming, but if you need something that will help you keep your focus all day long, active noise cancellation is definitely the way to go.