Can Active Noise Cancelling Remove All Noise?

Noise Cancelling
Written By Soundsight

Noise is a major problem that affects many people as it disrupts their sleep, work, and personal lives. Because of the nuisance of noise pollution, some wonder if active noise-canceling headphones can dampen the noise or even remove it completely. But can noise-canceling headphones really remove all noise? The answer is a resounding no because ANC headphones can only remove some noise in a person’s life but not create total silence.

In this article, I discuss whether headphones with active noise-canceling technology can remove all noise, the ANC headphones that can attenuate noise to a large degree, and the reasons they are not able to handle all high-intensity sounds.

Do active noise-canceling headphones remove all noise?

Not surprisingly, active noise cancellation cannot eliminate all background noise. Active noise-canceling headphones reduce a variety of noises and even reduce some of them to a level where they are not perceptible to the human ear. LINK HERE

Active noise cancellation works best on regular noise, such as aircraft engines and other mechanical sounds. It’s not as effective at reducing the noise of people talking nearby, wind noise, or high-pitched noises produced by police sirens or vacuum cleaners.

What ANC headphones completely eliminate all sounds?

No ANC headphones can completely eliminate all surrounding sounds. As such, the best you can get is an attenuation of noise in the first 1000 Hz of about -25 dB. This is not enough to get rid of all sounds; however, it reduces the ambient intensity by 60-70%.

Active noise cancellation effortlessly attenuates low-intensity, low-frequency sounds, especially if they are sustained and follow a clear pattern. But even sounds that are largely attenuated by active noise cancellation can still be heard if you listen carefully.

Active noise-canceling headphones are better than ordinary headphones in terms of noise reduction, but they are not the best devices for blocking out all sounds.

Even using the best earmuffs and earplugs for professional construction workers, which have been tested to reduce sound by up to 40 dB, you cannot enjoy total suppression of all background noise.

Why ANC headphones cannot block all sounds

If you’ve ever wondered why ANC headphones don’t cancel out all the noise, this section explains why:

For headphones with ANC to eliminate all noises, all aspects of the system that cancels out sound should operate flawlessly:

  • Accurate recording of any and all sound entering the array of noise-canceling microphones regardless of frequency and amplitude
  • Reliable communication between the noise-canceling microphones, the noise-canceling system, and the electronics that processes and receives the anti-noise signals
  • Instantaneous processing of the anti-noise signals with no positional or time lag
  • Accurate reproduction of the noise-canceling signals through the headphone driver
  • Minimal electrical noise from any component of the electronics that may interfere with the anti-noise signals

Any delay or imprecision in these essential elements of the ANC system inevitably introduces some degree of error into the ability to cancel out noises.

Quality ANC headphones need power

Active noise cancellation requires power, lots of power. The Sony WH-1000XM4, for example, has an internal battery that provides up to 38 hours of use before you need to recharge it. Using the ANC system, it can run for up to 30 hours. That may not sound like much, but the WH-1000XM4 is an efficient noise-canceling headset; other ANC headsets consume well over 25% more power.

Most ANC headphones can reduce noise levels by about 20 to 30 dB. And that’s among the best noise-canceling headphones on the market today.

Entry-level and mid-range noise-canceling headphones can reduce noise by 15 to 25 dB for specific frequency ranges, but they are not as consistent and much less effective. For example, Apple’s AirPods Max features technology that allows them to reduce low and mid-range frequencies (up to 1.5 kHz) by up to 20 dB. Most ANC headphones stop canceling noise near the 1 kHz mark.

Microphone recording quality

In addition to power consumption, a second problem with active noise cancellation is that even with very powerful headphones, they are not able to cancel all ambient
noise.

Microphone recording quality is limited in a headset because of the small capsule size of electret microphones built into the ear cups. Although electret microphones can have a frequency response of 20 Hz to 20,000 Hz, they are generally unable to accurately capture all high-frequency details.

A high maximum acoustic input is also necessary for the microphones to pick up loud noises without clipping and distorting them. Headsets must also operate at a high volume level to effectively reproduce large amplitude noise cancellation. For noise of a certain amplitude, the active noise suppression system must reproduce an anti-noise of similar amplitude to the noise source.

DSP for surgically accurate noise cancellation

The higher a noise’s amplitude, the harder it becomes for an ANC headset’s DSP to output a similarly loud noise. It’s easier to attenuate low-amplitude sounds because the margin of error isn’t high. The difference between a 30 dB sound and 31 dB isn’t as big as that of a 100 dB sound and 101 dB, which you’re going to get when a jet engine roars overhead.

Active noise-canceling headphones have difficulty reducing high-frequency sounds. They’re harder to suppress than low frequencies because the sound waves representing high frequencies are smaller and move faster, so the digital signal processor (DSP) must process the sound signals faster.

The higher the frequency, the greater the margin of error. This makes it even more impossible to completely eliminate high-frequency noise. Furthermore, the higher the amplitude, the more harmonics and distortion produced. This makes the problem even more complex.

Accurate sound reproduction

The headphone drivers’ are also a limiting component in achieving complete noise elimination. If your headphones cannot accurately reproduce a 100 dB anti-noise, then the two opposing noises will not cancel each other out. As such, you’ll hear more noise and perhaps harmonics caused by the distortion produced by the headphones.

Headphones with an active noise reduction system that attenuates most noises

Now that we established that active noise-canceling headphones do not eliminate all sounds, I will now introduce you to models that are the best when it comes to powerful active and passive noise reduction.

  • Sony Wh-1000XM3
  • Bowers & Wilkins PX
  • Bose QuietComfort 35 II

These headphones come with an active noise cancellation system that offers a high degree of attenuation, offers a great deal of comfort, and reproduces sound fun and colorful.

Sony WH-1000XM3

Even after the release of the WH-1000XM4, the WH-1000XM3 remains the benchmark active noise-canceling headset for its raw and powerful ANC provided by the HD QN1 noise cancellation processor. Its noise cancellation optimizer is also a nice feature to have that delivers optimal sound for high altitude air travelers.

In terms of active noise cancellation, the Sony WH-1000XM3 reduces sound to -30dB and -25dB on average. The bass and the first half of the midrange are strongly attenuated, while the rest of the spectrum is successfully attenuated to a high-level, thanks to passive isolation.

These headphones don’t have the most aesthetically pleasing or impressive design, but they offer great comfort, a lightweight 9-ounce (0.562 lbs) construction, and a battery life of about 30 hours with ANC (38 hours without).

The Sony WH-1000XM3 features Bluetooth 4.2 technology and aptX, aptX HD, and LDAC codecs for outstanding wireless audio quality. Sonically, the headphones are above average, with good extension but a colorful sound response and muddy bass.

Bowers & Wilkins PX

One of the best things about Bowers & Wilkins PX noise-canceling headphones is their ability to make our lives easier and more efficient. It’s an aesthetic and functional upgrade from traditional over-ear headphones with ANC and aptX HD. It features a powerful hybrid active noise cancellation system with 4 microphones for ANC (2 feedforward microphones + 2 feedback microphones) that can reduce most noises better than 90% of the headphones on the market.

But what sets the PX apart from other headsets with ANC is not only the hybrid noise cancellation technology, but also the craftsmanship with which the company has built it. The PX features a lightweight, rugged and luxurious construction, rich-sounding drivers, and an adjustable noise-canceling with multiple modes set in the Bowers & Wilkins Headphones app to enjoy your music in different settings. LINK HERE

With the PX, you can use the active noise reduction system without music because it’s highly effective and generates no noise like most ANC headphones. The Bowers & Wilkins PX is a great all-around headset. With its 40 mm angled drivers, the music is clear, detailed, and beautifully reproduced with plenty of basses. While it doesn’t have the best extension, the audio quality is still excellent for the price via wireless and cable.

Bose QuietComfort 35 II

Bose QuietComfort 35 II or QC 35 II is a well-known travel-friendly headset with noise-canceling technology. The Bose Quiet Comfort 35 II has 3 modes that can be controlled via the Bose Connect app:

1) Noise Cancelling – High: This mode activates noise reduction and allows you to listen to your music/calls in quiet environments.
2) Noise Cancelling – Low: This mode reduces the amount of noise but is more suitable for windy environments.
3) Noise Cancelling – Off: This mode disables the headphones’ noise cancellation and active equalization.

The Bose QuietComfort 35 II headphones offer the best travel experience, especially because they are lighter than other noise-canceling headphones at 8 oz (227 g) and are comfortable throughout the flight. The QC35 II is ideal for extended periods of use thanks to its 20-hour battery life. The battery isn’t as big as the Sony WH-1000XM3. Still, QC 35 II does a much better job blocking out human voices and other surrounding sounds.

The QC 35 II is also a great on-the-go headset with Bluetooth and NFC pairing capabilities, three levels of active noise cancellation, and access to Google Assistant. You can use Google Assistant to play music, make phone calls, access information, etc. Music playback is above average, just like the WH-1000XM3, but has more clarity and transparency.

FAQ

How much noise reduction do Active Noise Cancelling (ANC) headphones provide?

Active Noise Cancelling headphones typically provide about 15-20 dB of noise reduction, which is most noticeable in the low-frequency range. The amount of noise reduction that an active noise canceling headset can provide depends on the ANC technology and the product in question. It is not uncommon for entry-level or mid-range ANC headphones to reduce almost as much noise as high-end headphones, but high-end headphones offer more consistent performance.

Are there ANC headphones that can cancel out all noise?

No. ANC headphones are not capable of canceling all background noise. They do, however, provide excellent noise relief, reducing the daily stress of many users. Earplugs and earmuffs offer absolute noise reduction but are not practical for everyday use.

Learn more about The Differences Between ANC Headphones, Earmuffs, and Earplugs.

Conclusion

Evidence has shown that active noise cancellation technology is unable to reduce all noise, regardless of frequency and intensity, to the point of complete silence. Many inefficiencies must be resolved to create such a theoretical state of silence.

Because of these inefficiencies, headphones with active noise cancellation often come with a bit of noise, which is noticeable in various frequency ranges but can affect the music you are listening to, and even cause noticeable levels of distortion.

I wrote an article for those who don’t want audible noise from the ANC and prefer using their ANC headphones without listening to music, so be sure to read it. Also, the ANC headphones recommended in this article for those who want to reduce noise as much as possible (Sony WH-1000XM3, Bowers & Wilkins PX, Bose QC 35 II) all have near-perfect noise reduction.