Insights | Audio
The difference between active noise cancellation and passive noise cancellation
The hum of the city can be beautiful in its own way, but not when you’re trying to listen to your favourite song, making noise cancellation a critical feature of any good pair of headphones.
Whether that’s Active noise cancellation (ANC) or Passive noise cancellation (PNC), which is sometimes referred to as noise isolation.
But what is the difference between active noise cancellation and passive noise cancellation? How does noise cancellation help your day-to-day experience?
For answers to these questions and more, read on as we explore the different types of noise cancellation.
What is passive noise isolation? (PNC)
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 does not need battery life. This means more charge can be dedicated to the actual playing of music.
What is active noise cancellation? (ANC)
Active noise cancellation is the use of technology to cancel out external noise, so it doesn’t interrupt your listening experience.
Microphones analyse the external noises surrounding you and then play inverted soundwaves that cancel out the noises, preventing you from hearing external noise.²
Because sound is fundamentally a wave made of peaks and valleys, if you hear exactly opposing peaks and valleys simultaneously then your brain doesn’t perceive either.²
This means that any external noise outside of your headphones can be cancelled out using technology.
The Dyson Zone™ uses eight of these microphones for high quality ANC, delivering pure audio to you.
Active noise cancellation uses battery life. If you’re on a long journey or can’t charge your headphones often, this could be an issue. But the Dyson Zone™ noise cancelling headphones feature a 50-hour battery life when just using audio features.
Why you should have noise cancellation
If you live in a noisy area, have a busy commute, or work in an open plan office, noise cancelling headphones can be a great way to help block out the outside world and focus.
Say you’re on the bus, listening to your favourite podcast, but you must keep repeating the first few sentences because you can’t hear it over the arguments of some of your fellow passengers.
This is a job for noise cancellation.
Noise cancellation with a focus on low distortion, like in the Dyson Zone™, lets you hear your audio in a purer form. If you’re an audiophile that wants to listen to the greats unfiltered and how they intended, then noise cancellation is right for you.
Should I prioritize active or passive noise cancellation?
Active noise cancellation is typically the superior form of noise cancellation. This is because of its use of technology to completely silence 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 Zone™ features both.
By featuring eight microphones that detect soundwaves, algorithms that create opposite waves, ergonomic headphone cups that comfortably seal the ear, and intelligent signal processing, the Dyson Zone™ creates an enhanced listening experience with clean, pure audio.
The Dyson Zone™ features three ANC Modes
While most headphones only feature one ANC mode, the Dyson Zone™ features three. Let’s explore how the Dyson Zone™ can help you prioritize different elements of your life through ANC.
Isolation mode
Isolation mode silences the world around you by cancelling out aberrant noise using polarising sound waves. This is your classic ANC mode and allows you to fully focus on your music without worrying about the distractions of the day-to-day world.
This mode uses eight microphones within the headphone to monitor surrounding noise 384,000 times a second, cancelling background noise.
Transparency mode
Transparency mode can be activated by double tapping your headphones. This ceases all ANC so you can hear both your audio and the outside world. This is designed for the times when you need to focus on what’s around you, like when crossing the road.
It’s especially useful for fielding quick questions while you’re on the go.
Conversation mode
Finally, Conversation mode. This is the exact same as Transparency mode but for when you have your attachable travel visor attached. Conversation mode can be activated by pulling the visor down, this stops ANC and airflow so you can hear properly.
Beamforming
The Dyson Zone™ also features two extra beamforming telephony microphones that improve the sound quality of phone calls. If you receive a call while you have your headphones, you can take advantage of noise cancellation while you talk, for a crisp and clear phone call and then get right back to listening to your music without ever taking your headphones off.
More on noise cancellation
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 Dyson Zone™, then share your favourite place to wear it with the hashtags #MyDyson and #DysonZone.
¹ Molesworth, B.R.C. and Burgess, M. (2013) ‘Improving intelligibility at a safety critical point: In flight cabin safety’, Safety Science, 51(1), pp. 11–16. doi:https://doi.org/10.1016/j.ssci.2012.06.006.
² Hirnyj, D. (2012) Noise-Cancelling Headphones. dissertation. Available at: https://courses.physics.illinois.edu/phys406/sp2017/Student_Projects/Spring12/Danylo_Hirnyj_P406_Project_Report_Sp12.pdf (Accessed: 21 September 2023).
Nadia Taha
Email: nadia.taha@dyson.com