Loud Noises! How Do Noise Cancelling Headphones Work?

Noise Cancelling Headphones Work

How do noise canceling headphones work? It seems like magic, but there’s a lot of science behind these headphones.

If you’re the type that hates background noise when you’re listening to music or your favorite audiobook, you’re going to want to get noise canceling headphones.

They’re pretty amazing to have whether you’re working in a coffee shop or on an airplane. You can completely tune out the crying baby and enjoy your flight in peace.

Ready to geek out? Read on to learn how these amazing devices work.

How Do We Hear Different Sounds?

Let’s have a quick physics lesson. Sound is merely a vibration. The vibration usually happens in the air or water. Think about a small sound like a pin drop. That pin drop causes a small vibration in the air.

Now think about a jet engine breaking the sound barrier. There’s so much vibration in the air, the jet engine produces a huge amount of sound.

You might remember from school that sound travels in waves. These waves come in varying frequencies. Some are short waves and others are long waves. How fast the wave travels and the size of the wave will determine the frequency of the sound.

A wavelength has a couple of components. The high point or crest of the wave is called compression. The bottom point or trough of the wave is called rareform. When you see a visualization of a sound wave, what you’re really looking at is how the pressure of the sound wave vibrates in the air.

Compression is the high point of pressure, measured in amplitude.

These sound waves reach the eardrums and the waves vibrate off of the eardrum. The vibrations then go through the middle ear and inner ear. In the inner ear, tiny hairs (try not to think of an old man with hair coming out of his ears), pick up the vibrations and form sound in your ears.

Understanding what a miracle sound is will make you think twice about taking it for granted again.

How Do Noise Canceling Headphones Work?

Noise canceling headphones go beyond big headphones capable of sealing out unwanted sounds. The best way to describe how noise-canceling headphones work is by calling them a form of interference.

As we noted earlier, a soundwave has crests and troughs. When another soundwave meets another sound wave it can have two types of impacts – either constructive or destructive.

It’s like being in a club and trying to have a conversation with someone. It’s almost impossible to do because you can’t hear the person over all of the background noise. That’s a form of destructive interference.

The sound waves of the background noise interfere with the sound waves of the person’s voice.

A music band or symphony are a great example of constructive interference. The sound waves compliment each other, which makes it easier to hear all parts of the band. You can easily pick out the violin over the piano.

Now, if that symphony was performed by a bunch of four-year-olds, the result might be more destructive interference, but you get the picture.

Interference is the key to making noise canceling headphones work. How did they come about? Dr. Amar Bose was annoyed that he couldn’t block out the jet engine sound on a flight in 1978.

That lead to him creating the original sketches for the technology. The Bose brand has become synonymous with sound products of the highest quality since then.

Types of Noise Canceling Headphones

When you’re shopping for noise canceling headphones, you’ll find that there are two types: Active and Passive.

Passive noise control is using the material of the headphones to make a seal around your ears.

Some of the material that’s used is foam that is meant to absorb sound as it’s essentially a high-tech way to cover your ears with your hands. You pretty much get the same effect.

Active noise canceling headphones are surprisingly complex devices. They have a microphone inside the ear cup that monitors incoming noise. This microphone can measure the amplitude and frequency.

If sound can’t be blocked using passive means, then emits sound waves that interfere with the incoming background noise. The sound waves are the exact opposite of the incoming wave, which creates interference that you can’t notice.

The result is that you get a clearer sound without having to turn your headphones up too high.

The Best Noise Canceling Headphones

If you plan to purchase a set of noise canceling headphones, you’ll need to think about a few more things beyond active and passive headphones.

The first thing you’ll need to consider is whether you want your headphone to be wired or wireless. Wireless headphones offer convenience and a little less aggravation if you want to move around and listen to headphones at the same time.  Wired headphones usually cost quite a bit less than wireless.

Whether you have wired or wireless headphones, the noise canceling components run on a battery. You will need to charge the battery fairly often, depending on how much you use your headphones.

Some of the newer noise canceling headphone models have the ability to adjust the noise cancellation performance according to the environment you’re in. For example, if you’re on a flight that’s taking off, you’ll have a higher level of performance from your headphones than if you’re just sitting in your office.

Finally, you want to consider how comfortable the headphones are. Are you more comfortable with earbuds or plush headphones that go over your ears? This is a personal preference and is entirely up to you.

Think you’re ready to buy a new set of noise canceling headphones? See more here.

Ready to Buy Noise Cancelling Headphones?

Now that you know how noise-canceling headphones work, do you feel a little smarter? At the very least, you should have enough information to be confident that you know how to choose the right headphones for you.

Would you like more great tech tips? Find out what the best sites for streaming movies and gaming are.

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