Do Noise Cancelling Headphones Block Out Voices?

Noise cancelling headphones are great for diminishing the ambient noise whenever you’re in a loud public place. In fact, they are pretty much lifesavers if you have to sleep with a partner who snores all night long. But, do noise cancelling headphones block out voices?

In short, no. noise cancelling headphones don’t come with the technology to straight-up block someone’s voice. Unfortunately, we don’t still have the technology to just mute an annoying person right away. The best these headphones can do is to diminish the sound effects by a lot.

But, no. It can’t make the sound of the voice go away completely. Maybe if the person is quite away from you or whispering. Then, yeah, it just might block it out completely by treating it as an ambient voice.

As for the cases in which the person is close by or outright screaming, the answer is simply no. And, you know what?

Maybe that’s not a completely negative thing either. We’ll get back to that some other time. But for now, let’s have a look at the mechanism of noise cancelling headphones to find out how they work.

Do Noise Cancelling Headphones Block Out Voices

Types Of Noise Cancellation

Well, you gotta know all about the types of noise cancellations if you want to know how they work. So, here’s the tea. Normally, you’ll find two main types of noise cancellation. And they are active and passive NC respectively.

Depending on their usage, you’ll find some hybrid systems as well. But more on that later. Let’s stick to the basic premise for the time being. Here’s a brief overview of the two main types of noise cancellation and their features.

ANC (Active Noise Cancellation)

Out of the two, ANC is the more progressive one. It’s practically an evolved format of the Passive Noise Cancellation. It also requires better components and the system is much more complicated than PNC technology.

With ANC, for every standard frequency of the ambient noise, an equally opposite frequency comes into existence. Both of these frequencies are more or less equal in magnitude but completely opposite in amplitude. You can guess what happens next.

Yep. They actively end up cancelling each other out as they collide. As a result, you’re left with a calm and serene ambiance even in the midst of constant noise.

Now, keep in mind that ANC tech can pick up the constant and standard noise signals only. If the noise levels keep changing, they can’t keep up with the constant fluctuations. And understandably so as it needs time to generate and implement the opposite frequency.

So, it’s pretty futile if the frequency already changes by the time it applies the resonating frequency. As a result, active noise cancellation is pretty great for getting rid of the constant ambient noise in the background.

Such as – the sound of someone snoring really loud by you, or the buzzing of airplane mechanics. Or, some distant music from a faraway party interrupts your study sessions. It will help muffle all the noise as long as the frequency itself is constant and uninterrupted.

PNC (Passive Noise Cancellation)

Passive Noise Cancellation is like the primitive format of Active Noise Cancellation. In ANC, you use a complicated Anti-Noise Circuit to battle the ambient noise. While in PNC, you practically battle it in an old-fashioned style.

There’s no complex circuit board going on and neither do you have to deal with frequency levels. The whole point of any PNC tech is to just physically block any sound from getting past the barriers.

Quite similar to how you put your hands over the ears to protect them from any incoming loud noise. PNC tech provides physical resistance and tries to reflect the sound instead of actively cancelling it.

If you still have trouble envisioning the concept, just think of earplugs. More precisely, think of how they work. They cover the ears fully so there’s no gap anywhere whatsoever. And they work pretty well too, don’t they?

These earplugs represent perfectly how the PNC tech works. Their whole job is to physically prevent the sound from getting inside. They will either absorb it or directly reflect it back.

However, frequency plays a great role too for PNC tech as well even though it doesn’t actively need to use it. Like ANC, PNC cannot also restrict noise levels after they cross a certain high-pitched frequency.

Even more so, if the source of the sound is super close by. So, that’s a similarity that both of these systems share among themselves.

How Do Noise Cancelling Headphones Work In The First Place?

Before figuring out why they work or not, you should find out about their working procedure first of all. Without knowing that, you’ll never get to know why they don’t work the way you want them to work. So, here’s a brief overview of the core parts of ANC headphones.


Well technically, all headphones including the ANC already apply some form of passive noise cancelation by default. They do cover the ear when you put them in, after all.

The ANC part of it is just even more of an upgraded feature. And you need a microphone to pull that feature off. Like those spy movies, a microphone is kept inside the ANC headphones to listen in on surrounding noise levels.

It usually tracks a sound source with constant frequency and locks down on it. And since it’s placed inside the ear cups, it’s not visible at all. By figuring out the source of the sound and its frequency, it helps with the inference initiation.

Special Circuit System

You’ll find a special noise cancelling circuit alongside the microphone. Here’s an analogy that can help you to understand it better.

Think of the microphone as the gatherer and the circuit system as the main chef in a restaurant. Remember the noise frequency the microphone locked down on? The circuit has to prepare a coherent wave phase of opposite frequency off of that input.

For this, the circuit determines the frequency and corresponding amplitude of the incoming noise. Then it generates another wave phase which is equal in magnitude but takes a 180-degree turn phase-wise. Without this circuit, NC headphones wouldn’t work at all.


Just like how the mitochondria are the powerhouse of the cell, a battery powers the noise cancelling circuit. In fact, the battery is why the term ‘active’ is added to ANC headphones.

You need a constant supply of energy to power the circuit and create the anti-sound in the process. And it’s the job of the battery to provide that energy. Most ANC headphones use rechargeable batteries nowadays as they’re more environmentally friendly and affordable.


Finally, if the microphone is the shopper and circuits the chef, that makes our speaker the waiter, probably. What a weird analogy to provide, huh?

Well, anyway, the point is that speakers do the final deed by adding the anti-sound to the incoming sound. So, when this new sound collides with the annoying one, they somewhat cancel each other out.

It’s known as ‘destructive interference’ according to physics terms. Due to the differences in frequency, when they overlap, they actively cancel out the other one’s effect.

As for PNC headphones, there’s not much difference framework-wise. They don’t, however, include batteries and stuff. And you already know how old-fashioned headphones work so let’s not waste time on that.

Why Can’t Noise Cancelling Headphones Block Out Voices?

Whether it’s ANC or PNC headphones, neither can effectively block out human voices. And here’s why.

The Randomness Of The Waves

When you’re in a public space, or anywhere for that matter, you’ll find that nothing is constant. Everyone’s always on the move and there’s also something different happening every second.

Especially if it’s like a gathering where many people keep on talking at once. Once there’s some distance, it all kind of merges and feels like a single distant humming. But when you’re right in the middle of it, it’s like you can hear everything at once.

If you wear noise cancelling headphones at an event like this, it can never pick up on a single source of noise. As a result, the circuit system in the ANC headphones can’t come up with an anti-frequency in time too.

You should try putting on such headphones in a public space, without music, to see what happens. You’ll find that there’s almost no change whatsoever. The sound may even feel more amplified at times.

The passive headphones work a little bit better though. Since they collectively try to block all the incoming noise instead of doubling down on a single frequency. But even then it’s really hard to keep up due to all the randomness.

Proximity Issues

NC headphones work pretty great when it comes to blocking distant sounds. As mentioned above, the further you’re from a certain noise source, the less it affects you. The frequencies all seem to get mashed up together as you can’t pinpoint the sources.

Provided that all the noise sources are more or less on the same level. It’s not going to work if there’s a high gap in their magnitude.

So, when you’re far away, the ANC headphones can generate opposite frequencies to block the sound out. But even then, it’s not always accurate and you can still hear someone if they have a high-pitched voice.

Even if the headphones can muffle the voice a bit, it can’t make it fully go away. And the closer you get, the more the situation worsens.

Turbulent Frequency

Speaking of high-pitched voices, frequency plays the most important part in blocking out noises or voices. You have already pretty much figured that out, hopefully. But did you know that there’s a limit to the frequency level that NC headphones can actually deal with?

For instance – we humans can’t hear anything below 20 Hz or over 20000 Hz. A similar concept works with such headphones. They work perfectly as long as the frequency level is below 500 Hz. It can do a good enough job up to 1000 Hz but deteriorates as it goes up.

But when someone’s talking, they can often exceed this level and go way over. Especially when someone talks in a pretty exciting voice. Again, some people generally have a pretty high-pitched voice so there’s that too.

As you can’t moderate how someone’s supposed to express themselves, it’s hard to keep a track of frequencies like these. So, if you’re around someone who talks in a really loud voice, you cannot really ignore or block it. Even with both PNC and ANC headphones.

Tips On Using Noise Cancelling Headphones To Block Out Voices

Well, it’s already established that you cannot thoroughly block someone’s voice via noise cancelling headphones. But hey, we can certainly try, no? Here are a few tips you can try out to achieve that phantom effect.

1. Add An Extra Layer

Yeah, it does seem pretty try-hardy at this point, but if it works, it works, right? When all else seems to go downhill, you can really use an extra layer to block all the noise out. It will at least muffle the noise a little bit more.

Remember how normal ANC headphones work up to about 1000 Hz or so? Well, by adding a few extra passive layers, you can increase the resistance to 500 Hz more. That little bit of uplift can certainly make a difference.

Here’s what you can use to add an extra layer to your existing noise cancelling headphones.

  • industrial-grade earmuffs
  • foam earbuds/earplugs
  • make-shift cotton earplugs

However, if you’re using cotton, make sure to not use it in a stringent amount. They can easily get inside in your ears and it’s really hard to get them out without professional invocation. Actually, if you’re not confident, it’s just best to not use them in the first place.

In fact, lots of people have issues with measures like these. Not just the cotton plugs, but the whole ‘inserting random items into the ears’ in general. And understandably so as they can indeed come across as super uncomfortable for sensitive users.

Starting from accidental blockage and comfortability issues, they can cause itchiness as well if not used appropriately. Again, the earbuds can sometimes clamp on too tight to the ears and that’s another hassle to deal with.

So, uh, proceed with caution if you’re resorting to remedies like these. Just because they work great for some people, doesn’t mean it has to work well for you too. It’s totally okay. Just move on to the next few measures and see if they provide a better result or so.

2. Use Hybrid NC Headphones

Nowadays, you’ll find lots of advanced-level NC headphones utilizing both the PNC and ANC technology. Well actually, they are primarily ANC headphones, with just a splash of PNC thrown into them.

Theoretically, the concept is similar to providing an extra layer one. These headphones focus greatly on the framework and thus, make sure they are more resistant against ambient sound.

Again, a subtle reminder that NC headphones can’t fully block out voices, neither actively nor passively. It’s just that these hybrid headphones provide better resistance, that’s it.

And the downside of these headphones? They cost a lot. Like the price is often considerably high for just a pair of headphones. As a result, it’s often a dilemma to decide whether they’re actually worth it or not.

3. Try Out White Noise!

Now, this one’s a lifesaver. The concept of white noise is quite similar to the ‘destructive interference’ one. But instead of seeking out a certain frequency to replicate it, white noise just drowns out everything in general.

Or at least tries to, that is. Depending on the extremity of the noise or voice, there’s no saying whether it will actually work out or not. But it’s certainly well worth trying out.

And why it’s worth it, you ask? If you have ever visited a waterfall or stayed by the raging ocean, you already know the answer. Have you ever noticed how you can hear almost nothing but the sound of the water in those places?

Forget cacophonous sounds, you can’t even grab the attention of someone next to you unless you’re screaming. That’s just how powerful white noise is.

So, as a last resort, you can definitely put on some white noise to see if it lessens the impact. In addition to muffling the incoming noise, it will also help you to calm down. The therapeutic effect itself is enough of an incentive to try them out right away.


So, do noise cancelling headphones block out voices? By now, you already know that the answer to that question is no, unfortunately. But hey, that’s not necessarily a bad thing. Not unless you decide to treat it like one.

Someday, this little interruption might just become a life-saving scenario for you. And don’t worry. With the rate at which current technology is constantly progressing, we can certainly expect severe changes soon enough.

Maybe then you can fully block out someone’s voice with the advanced noise cancelling headphones. But till then, you’ll just have to make it work with the hybrid NC headphones and earplugs.

Best of luck!

How Noise-Canceling Headphones Work

John Ryan JR

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