If you want to drown out the outside world while listening to your tunes, noise-cancelling headphones are a great purchase. But how do they work, and what should you look for when buying a pair?

Let's break open noise-cancelling headphones and see how they work.

Different Kinds of Noise-Cancelling Headphones

Noise-cancelling headphones come in two different types: passive, and active. As you can tell by the names, passive headphones block out the sound without doing anything extra; all of the sound-cancelling "technology" is within the headphone's construction and material choice.

Active headphones, on the other hand, actively work to cancel out the sound using sound cancellation.

So, how do they differ, and which one should you buy?

How Do Passive Noise-Cancelling Headphones Work?

A pair of passive noise-canceling headphones
Noise Canceling Headphones Laying Flat Over White Background

Passive noise-cancelling headphones aren't complicated in design. The headphones are designed to deaden external noise by using materials good at muffling sound. There's nothing else past the material, meaning the headphones are taking a passive role in cancelling noise---hence the name

Of course, what the headphones use depends on the kind of headphones you're buying. A pair of in-ear headphones, for example, may use different sound cancelling materials than over-ear.

In general, over-ear headphones come with the best passive cancelling. In-ear headphones can only do so much with their small size and proximity to the eardrum.

When Passive Noise-Cancelling Headphones Are Best for You

Of course, this passive noise-cancelling method won't be as efficient as an active one. Active noise-cancelling headphones typically use passive methods on top of the additional features. However, there's still plenty of reason why you should get them.

For one, they're cheaper. If you want a pair of headphones that can block out soft ambiance noise, you may not need to spend extra on active headphones to achieve this. As a result, you can get passive headphones and save yourself some money.

Also, active noise-cancelling headphones require power for their mechanisms to work, via a USB cable or batteries. If this sounds like a hassle to you, you're probably better off with the "dumber" passive headphones.

How Do Active Noise-Cancelling Headphones Work?

A soundwave representing active noise-cancelation
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Active noise-cancelling headphones work by making a constant effort to mute the sounds around you. To do this, they need to alter the sounds that are entering your ear. That way, only the music from the headphones will be heard, and anything outside will become muted.

Active noise-cancelling headphones work by listening to the sound around you. For this, a microphone is required, which you'll find installed on all active noise-cancelling headphones. This tracks the noises occurring around you and measures the sound waves that make up those sounds.

If you've ever seen someone speak near an oscilloscope, with sound waves appearing on-screen, these are what the headphones are detecting. When sound is detected, this must be cancelled out. So, how do headphones do that?

In contrast to when you speak into an oscilloscope, have you seen what happens when it's dead silent? You'll notice the bar flatlines. As such, it's the headphone's job to take the sound waves around it and cancel them out to create a flatline.

The way it does this is by emitting a wave that is the direct inverse of what it's hearing. The peaks and troughs of the sound waves meet one another and cancel each other out, which results in a flatline; in other words, sweet silence.

When Active Noise-Cancelling Headphones Are Best for You

Active noise-cancelling headphones don't come cheap, but they do their job very well. If you're working in noisy areas and regular headphones aren't good enough to block the sound out, active noise-cancelling headphones are the best choice for you.

Should You Buy Noise-Cancelling Headphones?

Noise-cancelling headphones are fabulous, but they do require a significant financial investment. As such, not everyone will need noise-cancelling headphones, so you should think hard on if you need to spend the extra money on them.

People who benefit the most from noise-cancelling headphones are those who work or travel in very noisy areas while listening to music. These outside noises can interfere with your audio and make it hard to appreciate the music playing in your headphones. Noise-cancelling headphones are a smart choice for listening to music in louder environments.

Meanwhile, if you're thinking about buying these headphones for the sake of merely blocking out sound, you may want to consider cheaper alternatives. Earplugs, for instance, are very affordable yet efficient at blocking out noise. If you don't plan on listening to music in a loud environment, noise-cancelling headphones may be a waste of money.

How to Pick the Best Noise-Cancelling Headphones

Learning about noise-cancelling headphones is one thing; choosing one that's right for you is something else. With so many models out there, which ones are best for you?

When it's time to choose new headphones, you need to ask yourself how much you're willing to spend. This constraint will narrow down your range depending on your budget needs.

Buying Noise-Cancelling Headphones on a Budget

Unfortunately, if you're low on funds, you may find noise-cancelling headphones too expensive for your budget---even for the passive models. Passive noise-cancelling headphones hover around the $100 range, while active models can go from mid-low $100s and upward.

Regardless, if you do have the funds for a cheap, but good, pair of noise-cancelling headphones, there's plenty of choice. We discussed the most affordable noise-cancelling headphones for students before, so be sure to read our recommendations for some money-friendly ideas.

Buying Noise-Cancelling Headphones With Unlimited Budget

On the other hand, if money isn't an issue, you'll find that the world of noise-cancelling headphones opens up to you. The more premium models aren't cheap---they often have a $200-300 price tag---but they're well worth the money.

If you're on the hunt for the ultimate in noise-cancelling headphones, be sure to try the best noise-cancelling headphones for audiophiles. Never make such a large purchase without consulting reviews first, else you may be left disappointed.

Learning About Noise Cancellation Technology

Noise-cancelling headphones may seem like magic at first, but they're easy to understand. Passive headphones attempt to deaden the surrounding sound using dense materials, while active headphones try to create the inverse of the sound waves of your surroundings.

Noise-cancelling headphones are fabulous, but how about isolation headphones? If you need some advice on distinguishing the two, be sure to read up on noise cancellation vs. isolation headphones.