The difference between active noise cancellation and passive noise cancellation

Passive noise cancellation, or noise isolation, is the use of physical design to prevent interruption from external noise. This typically takes the form of cushioning headphone ear cups or well-fitting earbuds.¹ 
 
By sealing your ear into a specific area, passive noise cancellation blocks out external noise from being able to reach your ear.¹ 
 
Because noise isolation fully relies on physical design instead of the use of technology, it doesn't need battery life. 

Active noise cancellation is the use of technology to cancel out external noise, so it doesn’t interrupt your listening experience.  

Tiny microphones monitor external sounds and inverted sound waves are generated, mimicking the incoming noise you want to get rid of.

When sound waves are offset by 180 degrees they become opposing and when they combine, they cancel each other out through what’s known as ‘destructive interference’.

The Dyson OnTrac™ headphones use eight noise-cancelling microphones for best-in-class ANC. They cancel up to 40dB of unwanted noise, for fully-immersive listening. So you don't miss a beat.

The Dyson OnTrac™ headphones use eight noise-cancelling microphones for best-in-class ANC. They cancel up to 40dB of unwanted noise, for fully-immersive listening. So you don't miss a beat.

If you live in the city, have a busy commute, or work in an open plan office, noise-cancelling headphones can enhance audio in noisy surroundings.  
 
Noise cancellation with a focus on low distortion, like in the Dyson OnTrac™ headphones, lets you hear your audio in a purer form. If you’re an audiophile who wants to listen to your favourite artists unfiltered and how they intended, then noise cancellation is right for you. 

Active noise cancellation is typically the superior form of noise cancellation. This is because of its use of technology to reduce the unwanted sound, whereas passive noise cancellation merely muffles it. 
 
There’s no need to choose between active noise cancellation and passive noise cancellation, as the Dyson OnTrac™ headphones feature both.  
 
With eight microphones that detect sound waves, ergonomically engineered ear cups that comfortably seal the ear, and intelligent signal processing, the Dyson OnTrac™ creates an enhanced listening experience with clean, pure audio.

A simple double tap on the outer cap switches between two ANC modes.

Isolation mode silences the world around you by cancelling out ambient noise using opposing sound waves. It’s your classic ANC mode and allows you to fully focus on your music.
 
This default mode uses eight microphones on the ear cups to monitor surrounding noise 384,000 times a second, cancelling background noise. 

Transparency mode can be activated by double tapping on the ear cups. It ceases all ANC so you can hear both your audio and the outside world. Transparency is designed for the times when you need to focus on what’s around you, like when crossing the road.

The Dyson OnTrac™ headphones also feature two extra beamforming telephony microphones that improve the sound quality of phone calls.

If you receive a call while wearing your headphones, you can enjoy crisp and clear audio and then get right back to listening to your music without ever taking your headphones off. 

The difference between passive noise cancellation and active noise cancellation is clear, and how they complement each other is even clearer. If you want pure audio for the best listening experience, you need both PNC and ANC. For more information, read about how noise cancellation enhances audio. 

If you have your own pair of Dyson OnTrac™ headphones, then share your favourite place to wear them with the hashtags #MyDyson and #DysonOnTrac.