Noise Cancelling vs Noise Isolation Explained

Noise cancelling headphones are some of the most sought after kinds of headphones among general consumers, and for good reason. They’re ideal for blocking out busy background noises when you’re out for a jog, walking the dog, or even studying. 

But one thing I’ve noticed, when buying headphones, is not knowing the difference between noise cancelling vs noise isolation.

So I did a bit of research… 

And in short, there are two types of noise cancellation methods in headphones. Active noise cancelling, which reduces or blocks outside noise, using microphones and a power source inside the headphones. And noise isolation or passive noise cancellation which uses physical insulation to block out noise without the use of any electrical components while preventing any sound from leaking.

While this is the short answer, there’s more details that can help in your headphone buying decision so let’s go over some things you may need to know. 

Noise Cancellation or Active Noise Cancellation, is tech that helps reduce or at times remove the immediate ambient background noise around you such as on a plane or at the office. By doing this it provides a quieter listening experience.

What is Noise Isolation?

Noise Isolation or Passive Noise Isolation, is the blocking of external noise. It also minimizes any sound leakage without any additional tech. These headphones instead use foam and other practical materials in the ear cups.

Noise Cancelling vs Noise Isolation: How do they work?

Now that we know what each of these features are…

 …let’s talk about how they work.

Active Noise Cancellation

To understand noise cancellation, you need to have a general understanding of sound. I’m no expert in physics but if you want to learn more about this topic, take a look at this explanation on how sound works. 

Sound travels in the form of waves. In these waves, they have high points called peaks and low points called troughs. If two sound frequencies meet and have relatively the same peaks and troughs, the result of the combined frequencies will be increased. 

Simply put, the combined soundwaves will make the sound louder. 

An example of this is when you’re in a crowded room at a party and everyone is talking. The soundwaves from each person, speaking at the same time, overlap each other increasing the overall sound in the room. When more people come into the room and start talking, the overall sound gets louder. This concept is called constructive interference.

The opposite of constructive interference is called Destructive interference. This is when one waveform is the total opposite to another waveform and this cancels each other out. For every trough and peak of one waveform, the opposite waveform has an opposite trough and peak at roughly the same points.

Imagine taking one soundwave, duplicating it and inverting it to be the opposite of the original.

This is where Active Noise Cancelling (ANC) comes in.

Illustration showing how active noise cancellation in headphones works.

Inside a pair of ANC headphones or ANC true wireless earbuds, there are tiny built-in microphones that are constantly listening for background noise. Once these microphones pick up a sound from the outside, it creates an opposite copy of that sound which cancels out that outside noise before it ever reaches your ears.

This function is running constantly, and requires a battery and frequent charges, if you plan on using it often.

Sound Isolation

When talking about passive noise isolation in headphones, it’s important to understand that it doesn’t require any sort of technology like ANC headphones. What passive noise isolation does is use the ear cups of closed-back over-ear headphones to create a seal around your ears. With this seal, it shields your ears from any ambient noise such as cars, TV, kids, or even pets. It also prevents sound from leaking out for people around you to hear. 

The material used in these kinds of headphones to isolate background noise is high-density foam and some additional padding that create layers of insulation around the ear. 

Besides material, the isolation of background noise depends on the actual design of the headphone’s ear cup, and the fit they have around your ears. 

In the case of earbuds or in-ear monitors, sound isolation will depend on the fit of the ear tips and how well the tips completely seal the canal inside. Normally these tips are made of foam or silicone material.

Which is Better? Noise Cancelling or Noise Isolating?

You’re probably wondering which noise reduction method is better? 

And the answer is…

…It’s hard to pick a definitive winner. They both have their advantages and disadvantages. 

Advantages of ANC Headphones

  • They block sound better than regular headphones – With so much noise around us everyday, it’s difficult to get even a few minutes of quiet time. Active noise cancelation can provide those precious few minutes of peace and quiet better than a regular pair of headphones. They do have some limits to the sounds being blocked but we’ll get into that a little later.
  • You have better volume control – We’ve all had experiences where we blast the volume in our headphones to block out the sound of the dog barking or the sound of the plane engine on a flight. With ANC blocking out these sounds, you can enjoy your personalized listening experience at lower volumes which, in the long run, will save your hearing.
  • Ideal for traveling – The biggest advantage is for travelers or people who like to listen to music while studying. With outside noise eliminated, you can concentrate on your studies without losing focus, or just get rid of that awful road noise or jet engine hum during long hours of traveling. 
  • Different Levels of Cancellation – There are rare moments where you don’t want to have full noise cancelation such as walking around your neighborhood or in a busy environment. Most ANC enabled headphones have multiple levels of cancelation so in these scenarios you’re aware of your environment.

While these pros are great, they aren’t without their drawbacks.

Disadvantages of ANC Headphones

  • Cost is a big factor – While ANC headphones need electronics inside to help block out ambient noise, regular headphones don’t. This is why headphones with ANC are more expensive. The manufacturers must charge for the costs of these materials.
  • Additional weight to headphones – The addition of microphones, batteries, circuitry, etc. inside ANC headphones, is going to sacrifice the light weight of the overall headphones. 
  • Quality of sound is affected – Headphones come in all price ranges. And as the old saying goes, you get what you pay for. Depending on the quality and price of ANC headphones, you may experience some slight hissing from the components in the headphones. More expensive ANC headphones however, are able to minimize this which also contributes to the price. Also, with everything it takes to block out ambient noise, you slightly compromise the sound quality of whatever you’re listening to.
  • Frequent charging – It’s no surprise that a majority of bluetooth headphones require charging. However, headphones that have active noise cancelling will require more frequent charges. That’s because when using ANC constantly, it needs a steady power source to continually run this feature. If the battery in the headphones dies, you won’t be able to use active noise cancelling until you recharge them. This doesn’t mean the headphones become unusable once dead. There are some headphones that come with a line-in cable so you can still use them as wired headphones, you just won’t be able to use the ANC feature. Regular headphones don’t have this issue which is something to consider when choosing your headphones.
  • ANC headphones don’t completely cancel out noise…but it’s darn close – If you remember, earlier in this post, the brief explanation of how active noise canceling works, you’ll recall that these headphones have tiny microphones inside that listen for ambient noise, creating a flipped version that cancels out the sound. While this technology is great, it’s not exactly perfect. That’s because these microphones have an extremely short amount of time to create a flipped soundwave. So instead of completely silent background noise, you’ll hear muffled background noise. While they perform great with lower frequency sounds like road noises, they tend to struggle a bit with shorter high-frequency noises like dog barks. 

Advantages of Passive Noise Cancellation Headphones

Man listening to music with noise isolating headphones
  • Lower Price – Compared to ANC headphones, passive isolating headphones are normally cheaper. Nowadays you can find some really decent headphones around the $100 range that will get the job done. 
  • Lighter Weight – Because passive isolating headphones don’t have extra components to help block out noise, they are arguably lighter which can help prevent ear fatigue and contribute to longer listening sessions. 
  • Longer Battery – With passive isolating headphones, there isn’t additional tech inside to draw on battery power. This can lead to longer battery life and less charging times. If you’re a heavy listener like I am, then charging times will be more frequent but will depend on your listening habits.
  • Better sound quality – Without additional methods to block out sound, the main priority will be on sound quality.

Disadvantages of Passive Noise Cancellation Headphones

  • Not ideal for traveling – Noise isolating headphones do a great job of blocking out ambient noise, but it doesn’t block out all noise. In fact, these kinds of headphones aren’t the best to take with you on plane rides. The constant loud rumbling of a plane engine can easily drown out music ruining the listening experience. and trust me, turning up the volume won’t help. 
  • Not a one size fit all – Everyone’s ears are made different which can affect the fit of noise isolating headphones and in some cases, earbuds. If your ears prevent a good seal, you’ll end up with sound leakage. That won’t be good for the people around you. 
  • Less Noise Blockage- Besides an improper fit, noise isolating headphones just don’t block out as much noise as active noise cancelling headphones.

Conclusion

At the end of the day, choosing your noise reduction headphones will depend on how you’re going to use them and your budget. 

I hope this helps you understand the differences between noise cancelling and noise isolation, and assists you in your buying decision. 

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