What Are ANC Headphones? How Does Active Noise Cancellation Work?

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ANC is a popular term in headsets these days. What are ANC headphones? How do they work? Let’s scroll down to the exact answers!

Active noise cancellation (ANC) headphones are becoming more and more popular because they offer users a high-quality listening experience. So what are the ANC headphones? How does active noise cancellation work?

Active noise cancellation (ANC), also known as noise control, is a technology that cancels all the noise from the outside world, making your world quieter.

This article will provide you with a comprehensive introduction to noise-canceling headphones. We will explain how they work and their variants as well.

Let’s read on to discover!

What Is Active Noise Cancellation ANC? 

The ANC headphones use noise cancellation technology. The headphones work by producing and delivering an anti-noise wave into the entire audio stream to remove external noise from the user’s ears.

All of the microphones encircling your head may help you focus and interact even among the crowd. ANC can also assist you in relaxing with your favorite music when running.

This type of technique was previously only available in huge, expensive headphones. With developments in the sound system industry, it is now commonly accessible. It comes in a multitude of different earbuds and wireless headphones. 

This function has grown in popularity to the point that almost every headset features some form of noise canceling.

How Does Active Noise Cancellation Work? 

How can a headphone cancel the surrounding sounds? Let’s discuss a bit of the technology in active noise-canceling headphones to figure out its operation.

Sound wave principle

The underlying principle of ANC is straightforward. Consider a chart of a sine wave with an arc’s height in an uptrend. Imagine the reversal of that, with the lowest level aligning with the positive wave’s peak. 

These two waves dismiss each other in the same way that combining 1 to -1 gets 0. As a result, if the waves reflect the audio signals, they cancel each other out, leading to silence.

The two sound sources cancel each other

The two sound sources cancel each other 

That’s what the term stands for. Active noise-canceling headphones include built-in mics that collect ambient noise. Then, the audio circuitry takes these noises and creates their counterparts to eliminate them. 

Arising problems

ANC would be straightforward to execute if all of the noises around us were as clear and consistent as the sine waves. The cancellation is also less expensive to make and is virtually always functional. 

Sounds, on the other hand, are rarely as consistent. Because of its sophistication, noise-canceling systems may struggle to create an accurate inverse. 

For continuous noises like the hum of an air conditioner, an active noise cancelling headphone typically works effectively. It’s more difficult to produce exact inverses for sounds with many variations in pitch and loudness or percussiveness.

As a result, dealing with someone’s singing voice or hand clapping is a tricky task. 

Furthermore, creating reverse waves for the lower-frequency sounds is quite simple. Higher frequencies, on the other hand, are more challenging to switch to.

Low-frequency and consistent noises are ideal for ANC. Manufacturers may have more opportunities to minimize high and transient noises.

You can learn more about the ANC system in this video.

Active Noise Cancelling Headphones And Passive Noise Cancelling Headphones Comparison

The operation in active noise cancellation and PNC (Passive Noise Cancellation) may confuse users sometimes. Learning about those terms helps you determine which is better for you.

What is PNC?

The concept of passive noise cancellation is more straightforward than the ANC. It happens when sounds get physically blocked from reaching your ear canal.

Earplugs are an excellent example of passive sound cancellation that is both effective and simple.

They efficiently restrict the transmission of sound waves to your eardrums. Then they decrease our susceptibility to noise in the surroundings and shield our hearing from the high sound intensity.

Earplugs decrease the effects of sound waves on human hearing by bouncing and consuming them in our hearings.

PNC allows sound waves from the noise outside to rebound the ear cups. Sound waves might also reach the ear cup padding.

Closed-back circumaural headphones and specific well-fitted earbuds provide passive noise canceling.

Noise-blocking passively is poor with supra-aural and open-back headphones. Many earphones on the market seem to be the same way.

See more:

Similarities between ANC and PNC

It’s worth noting that active and passive noise-canceling headphones have a lot in common. 

When properly adjusted, closed-back headphones are the greatest for passive noise canceling. Active noise-canceling headphones utilize the same feature set as well.

It’s worth remembering that active noise-cancellation adds to the reduction given by the passive noise-cancellation.

There are various active noise-canceling earbuds. These earbuds can keep sound waves from accessing the eardrum by blocking the ear canal. With this approach, the ANC circuitry makes use of the earphones’ passive reduction once more.

Differences between ANC and PNC

Since ANC and PNC apply different technologies, they differ in many aspects. Let’s compare to see which one suits you more.

Sound quality

ANC earbuds and headphones produce noise to suppress external noises. Hence, passive noise isolation provides more excellent sounds.

Your music will become substantially distorted as a result of this. While limiting the noise outside, passive noise isolation gives a more accurate depiction of your audio.

Noise cancellation

Both ANC and PNC work well at lessening the noise. However, according to the frequency band being suppressed, each offers advantages and disadvantages.

PNC headphones can reduce mid-to high-frequency sounds from 15dB to 30dB. 

Active noise-canceling headphones, on the other hand, are superior at reducing low frequency. ANC can decrease total ambient noise by about 30dB. It can also drop about 60dB in noise from lawnmowers and traffic.

Power consumption

Full battery life is necessary to generate the noise to block ambient noises before they reach your ears in active noise-canceling headphones.

Even though your PNC headphones require Bluetooth to work, they nevertheless consume less power than ANC Bluetooth devices. You need to pay attention to the battery life for their function.


Both ANC and PNC let you hear music at low volumes. PNC, on the other hand, is safer for your hearings in general. Because ANC creates both opposite and equal noise, it effectively cancels the outside noise.

You don’t need to turn up the volume to enjoy your music. At the same sound level, you’ll always get more decibels of sound than you can with PNC.

What Are Three Types Of ANC?

While the core ANC principle remains the same, there are three distinct ways to apply it: feedback, feedforward, and hybrid. Each method has advantages and disadvantages.


Mics stay on the outside in the ear cups of feedforward noise-canceling headphones. Before reaching the user’s ears, the headphones’ exterior picks up the noise. As a result, the anti-noise output will delay appropriately.

The anti-noise output is a time-delayed sound signal with an opposite polarity that wipes out the genuine ambient noise. It goes with the original audio stream to operate the headphone speaker.

Gathering external sounds before reaching the eardrum offers the ANC circuit enough time to generate the appropriate anti-noise.

High-end circuits may suppress frequencies up to 2 kHz due to the delay between recording the sound and the signal entering the ears.

The extra time also aids in the better cancellation of transient noise.

The biggest downside of feedforward noise-canceling headphones is that they lack self-correcting. Because the microphone sits outside the headphones, it can’t capture the sound produced by the headphone speaker to determine how effective the circuit’s anti-noise transmission is.

As a result, if feedforward headsets have an incorrect position, the cancellation may cause more damage than benefit.

Wind noise is another problem in feedforward construction. The PNC in these headphones will filter out the wind noise. The external microphone, on the other hand, will not work. 

Because there is no method to self-correct the wind noise within the anti-noise data, there will be more wind noise in the headphone signal. 


Feedback noise-canceling headphones have the mic within their body.

The microphone gathers up noise from inside the ear cups as well as sound from the speaker. It’s also significantly closer to our ears than it would be if it weren’t within the headphones.

In this device, the self-correcting system works while the anti-noise input gets caught.

The mic signal operates in sync with the sound source’s intended audio stream. The difference between these two signals is the noise. The active noise cancellation generates an anti-noise input to eliminate the noise by phase cancellation.

The input and anti-noise signals have to work together at the appropriate levels to generate a clean and noise-free signal.

Feedback noise-canceling headphones work over a more comprehensive frequency range. Technology is essentially independent of the external environment.

As a result, the feedback appears to be more efficient if you wear the headphones incorrectly.

Because of the tiny wavelengths of these noises, feedback devices have poor high-frequency suppression. The noise isolation is also contingent on bouncing across the area between the headphone and the ears.

Improper feedback designs might cause feedback between the headphone speaker and microphone. The discrepancy is comparable to how mics react to speakers and displays, although it is uncommon.


As the name implies, active noise-canceling headphones integrate feedback and feedforward principles. Multiple mics on the outside and inside of the headphone body are necessary for this.

Hybrid methods seem to be harder to develop and cost more money. Still, high-quality hybrid headphones perform an excellent job of bringing the advantages while wiping out many of the disadvantages of the two methods.

Hybrid headphones combine feedback and feedforward system

Hybrid headphones combine feedback and feedforward system 


We have introduced and explained the basics of noise-canceling. You can choose either ANC or PNC headset to serve your different purposes. Your selection is also more diverse because of the three active noise cancellation types available.  

Hopefully, you will find this article helpful. If you need any further information, please feel free to ask. Thank you for reading!


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