So you’re looking into getting a pair of active noise-cancelling headphones/earplugs and you’re wondering if you can still listen to music or if these headphones will provide a good listening experience.
Do noise-cancelling headphones work with or without music? Active noise-cancelling (ANC) headphones, by the meaning of their name, allow us to listen to music and audio while providing active noise-cancellation. Of course, there are also active noise-cancelling earplugs and hearing protection that do not connect to an audio playback source.
In this article, we’ll discuss active noise-cancelling headphones in more detail and go through a few examples of noise-cancelling headphones and earplugs to get a better idea of which types allow music listening and which types do not.
How Does Active Noise-Cancellation Work?
While passive noise-cancellation involves physically blocking sound waves from reaching the eardrum, active noise-cancelling involves altering the audio signal to eliminate external noise.
Note that all headphones have, to varying degrees, some passive noise-cancellation due to their form factor around the ear.
So how does active noise-cancellation work? It actually starts with a microphone.
In order to cancel what is considered noise, ANC headphones must be able to sense the noise in their environment. There is no better way of doing this than with a microphone. More specifically, ANC headphones generally utilize miniature electret condenser microphones for this purpose.
For more information on electret microphones, check out My New Microphone’s Complete Guide To Electret Condenser Microphones.
Once we have an audio signal the represents the noise of the system, we can adjust its phase and play it back to effectively cancel out the actual noise via deconstructive wave interference. In other words, we process the built-in mic signal to be our “anti-noise” audio.
When listening to music (or any other audio), this anti-noise signal is appropriately amplified before it is summed together with the intended audio signal. The altered audio signal causes the headphone driver to produce the intended audio and cancel noise at the same time.
There are 3 different types of active noise-cancellation we should be aware of:
Feed-Forward Active Noise-Cancellation
Feed-forward ANC headphones measure noise with a microphone to the exterior of the headphone body. Since the noise is picked up by the mic before it reaches the listener’s ear, this “noise signal” must be processed and delayed accordingly.
Like all ANC circuits, the noise signal is combined with the intended audio signal to drive the headphone speaker.
The main benefit of feed-forward systems, as I’ve suggested, is that the mic captures the exterior noise well before the noise would hit the eardrum. This allows ample time for the ANC circuit (the amplifier, delay/phase shift circuit and summing amp) to produce the proper anti-noise.
This additional time may seem insignificant but in high-quality designs, it will improve the cancellation of higher frequency sounds up to 1-2 kHz (something a feedback ANC circuit has difficulty doing). Additionally, it helps to provide better cancellation of transient noise, though no ANC can fully cancel loud transient noises.
Unfortunately, feed-forward systems have no way of self-correcting since the mic is outside the body of the headphones and does not pick up the resulting sound from the headphone speaker/driver.
What does this mean? Well, feed-forward systems may be designed to cancel noise effectively but if the headphones are positioned incorrectly; the noise is coming in at an odd angle, or the headphones are misused in another fashion, the ANC circuit may be ineffective. Even worse, the ANC may amplify the noise at some frequencies!
Another con of the feed-forward design is that the mic will pick up wind noise in outdoor environments while the passive isolation of the headphones effectively blocks out the wind noise. In practice, this actually results in wind noise being added to the signal and getting heard by the listener since the anti-noise signal has nothing to cancel out.
Feedback Active Noise-Cancellation
Feedback ANC headphones have their microphones placed within the headphones. In this system, the anti-noise signal is being captured and processed instantaneously.
The mic’s signal is compared to the original audio signal and the differences between the signals is considered noise. The ANC circuit then produces an anti-noise signal to be summed together with the intended audio signal.
This procedure does not only produce a cleaner signal with less noise but it’s also self-correcting.
Compared to feed-forward systems, feedback ANC works on a broader range of frequencies. It also has the advantage of being more effective when the headphones are not worn correctly since the system is contained on the inside of the headphones.
A con of feedback ANC systems is poor high-frequency cancellation due to the short wavelengths of these sounds and the way in which they reflect/bounce around the space between the ear and headphone cup.
Imperfect designs may result in actual feedback between the microphone and headphone driver similar to how microphones feedback with loudspeakers and monitors, though this is rare.
To learn more about microphone feedback, check out my article What Is Microphone Feedback And How To Eliminate It For Good and 12 Methods To Prevent & Eliminate Microphone/Audio Feedback.
Similarly, ANC can accidentally filter out the sound waves of the intended audio if the processing circuits are not designed properly. This is particularly true with low-frequency long-waveform sounds.
Hybrid Active Noise-Cancellation
A hybrid ANC system, as the name suggests, combines principles of feed-forward and feedback active noise-cancellation. This requires multiple microphones on the inside and outside of the headphone body.
Hybrid systems are much more complex to design perfectly and do cost more but high-quality hybrid systems do a great job of combining the benefits while cancelling (pun intended) much of the cons between the two systems.
Listening To Music With ANC Headphones
As you can imagine, listening to music with ANC headphones is possible. There are plenty of ANC headphones designed for music listening.
ANC Headphone Examples
Let’s have a look at some ANC headphone examples:
The Bose 700 (link to compare prices on Amazon and B&H Photo/Video) pair of Bluetooth wireless over-ear headphones boast a whopping 11 levels of active noise-cancellation.
On top of ANC, the Bose 700s have built-in Google Assistant and Amazon Alexa and a multitude of different functions and controls for smart technology.
The Sony WH-1000XM3 (link to compare the prices on Amazon and B&H Photo/Video) is a pair of Bluetooth wireless headphones with ANC based on Sony’s dedicated HD Noise-Canceling QN1 processor and Sense Engine.
Sense Engine is designed to automatically adjust the level of noise-cancellation based on the ambient sound level in your environment. If quick communication is needed, the Quick Attention feature stops the ANC by simply covering the right earcup with your hand.
JBL LIVE 650 BT NC
The JBL LIVE 650 BT NC (link to compare prices on Amazon and B&H Photo/Video) is a pair of Bluetooth wireless headphones with built-in earcup controls to engage and disengage active noise-cancelling.
Bower & Wilkins PI4
The Bower & Wilkins PI4 (link to compare prices on Amazon and B&H Photo/Video) is a pair of Bluetooth wireless earphones with adaptive active noise-cancelling.
These earphones come with two mics for telephony and two mics for the ANC circuit (one on each earpiece). The ambient pass-through feature allows outside audio to penetrate through to your ears when activated.
Bower & Wilkins does not specify an exact dB reduction for its PI4 ANC circuit.
ANC Earplugs & Hearing Protection
On top of headphones designed with active noise-cancellation, there are hearing protection devices that utilize ANC as well.
These ANC earplugs and earmuffs are typically designed for hunting and shooting ranges. Their circuits are even more involved, allow for amplification of low-level environmental noise below a certain threshold and noise-cancellation of louder sound pressure levels above this threshold.
Hearing protection is important. In most instances, when your hearing becomes damaged, it is damaged for good.
The NIOSH National Institute for Occupational Safety and Health) and the OSHA (Occupational Safety and Health Administration) have their own standards and guidelines about the duration we can be exposed to various sound pressure levels before sustaining damage.
Below is a table with both standards laid out:
|NIOSH Standard (dBA)||Equivalent Sound Pressure Level (at 1 kHz)||Maximum Exposure Time Limit||OSHA Standard (dBA)||Equivalent Sound Pressure Level (at 1 kHz)|
|127 dBA||127 dB SPL|
|1 second||160 dBA||160 dB SPL
|124 dBA||124 dB SPL|
|3 seconds||155 dBA||155 dB SPL
|121 dBA||121 dB SPL|
|7 seconds||150 dBA||150 dB SPL
|118 dBA||118 dB SPL|
|14 seconds||145 dBA||145 dB SPL
|115 dBA||115 dB SPL|
|28 seconds||140 dBA||140 dB SPL
|112 dBA||112 dB SPL|
|56 seconds||135 dBA||135 dB SPL
|109 dBA||109 dB SPL|
|1 minute 52 seconds||130 dBA||130 dB SPL
|106 dBA||106 dB SPL|
|3 minutes 45 seconds||125 dBA||125 dB SPL
|103 dBA||103 dB SPL|
|7 minutes 30 seconds||120 dBA||120 dB SPL
|100 dBA||100 dB SPL|
|15 minutes||115 dBA||115 dB SPL
|97 dBA||97 dB SPL|
|30 minutes||110 dBA||110 dB SPL
|94 dBA||94 dB SPL|
|1 hour||105 dBA||105 dB SPL
|91 dBA||91 dB SPL|
|2 hours||100 dBA||100 dB SPL
|88 dBA||88 dB SPL|
|4 hours||95 dBA||95 dB SPL
|85 dBA||85 dB SPL|
|8 hours||90 dBA||90 dB SPL
|82 dBA||82 dB SPL|
|16 hours||85 dBA||85 dB SPL
Examples Of ANC Earplugs & Hearing Protection
Let’s have a look a few examples of hearing protection devices with active noise-cancellation:
Honeywell Howard Leight Impact Sport
The Honeywell Howard Leight Impact Sport (link to check the price on Amazon) is a pair of earmuffs that amplify ambient sounds up to a safe level of 82 dB and instantaneously cancels sounds above 82.
An external 3.5mm audio jack allows these earmuffs to double as stereo headphones when connected to an MP3 player or other audio sources.
It has a Noise Reduction Rating (NRR) of 22 dB.
Walker’s Razor (link to check the price on Amazon) is a pair of active noise-cancelling earmuffs. A 3.5mm jack is included for use with iPods, MP3 players and hand-held radios.
It has a Noise Reduction Rating (NRR) of 22 dB.
The ZQUIET QuietOn (link to check the price on Amazon) is a pair of wireless active noise-cancelling earbuds designed for sleep improvement.
What’s the difference between noise-cancelling and isolating headphones? Active noise-cancelling microphones utilize live recordings of the acoustic environment and phase-cancellation within the audio signal to reduce noise while noise-isolating headphones block sound waves physically from entering the listener’s ears.
Why is active noise-cancelling so expensive? Active noise-cancellation is typically expensive because it requires complex circuits that record noise via a microphone; amplify that noise signal, and combine that signal with the audio source’s signal with a phase shift that perfectly cancels out the external noise before the collective sound waves reach the ear. That being said, they aren’t that expensive.
To learn more about expensive and cheap headphones, check out my article Are Expensive Headphones (Or Cheap Headphones) Worth It?