Noise Canceling Earplugs – How Do They Work

Noise-canceling earplugs can be the perfect companion for those who travel a lot but can’t live without their daily dose of music.

Technically, noise-canceling earplugs mean only the sound you desire reaches your ears while the rest is blacked out.

And that seems sort of magic taking place with the humble-looking earplugs capable of pulling off such a thing.

That said, there is science behind it and not magic, of course. Let’s try to find out how noise-canceling earplugs work in reality.

What Is Noise?

What Is Noise?

Let’s understand noise first before we delve into ways to cancel the same. Now think of the ripple that gets created on the water’s surface when a stone is thrown in it.

Think of sound waves as something similar. However, it travels through the air from the source (where the sound is originated) to the destination (where the listener is located).

More specifically, for most practical purposes, the sound is, in reality, the compression and decompression caused to the air particles while flowing through it.

It, in turn, causes changes in the air pressure, howsoever slight or extensive those might be.

The power of such changes in the air pressure is referred to as the amplitude.

These changes in the air pressure are picked up by our ears and are decoded as sound by the brain.

How Do Earplugs Cancel Out Noise?

How Do Earplugs Cancel Out Noise?

The way external noise is canceled is referred to as anti-phase. Also, it is a simple process on paper but can be extremely tricky to get it right on an actual device.

Before delving more into how that happens, we need to clear up some simple terms such as the trough or the peak.

Here, peak refers to the top-most point of the wave while the trough is the lowest portion of the wave. The distance between the successive crests of a wave is termed wavelength. 

If one wave is complemented by another wave having identical peak and trough, the two waves are referred to be in a condition that is described as ‘in-phase.

It leads to an even stronger wave or a louder noise in real-world conditions.

However, in a situation where one of the waves is delayed exactly by half a wavelength so that the trough of one wave matches up with the peak of another wave, you have a situation referred to as ‘out of phase.’

It is what you call anti-phase, as the negative pressure of one wave cancels out the positive pressure of another wave.

In the end, you have zero pressure and hence zero noise.

That is how noise cancelation is achieved though things aren’t as straightforward when trying to implement the same on an actual device such as the earplug in real-world conditions.

Noise-Canceling In Earplugs

Noise-Canceling In Earplugs

In an earplug, noise-canceling is achieved by way of tiny mics placed on the exterior.

The role of these mics is to recreate sound waves that are the exact opposite of the prevalent noise outside.

They detect the sound waves and create the exact opposite of those waves and in real-time.

This way, the user is spared from listening to all that is happening in the surroundings while only pure music enters their ears.

However, the above is only the ideal scenario and might not be the case in the real world, mainly when you are in a crowded place and there are lots of people talking.

In such a scenario, the external mic and the supported electronics might be overwhelmed.

They may not produce enough anti waves to cancel out the sound waves from the surrounding. Also, by the time the anti-wave is created, there might be a different noise created outside.

However, with better electronics and a powerful processor onboard, some earplugs indeed do a markedly better job in canceling out the exterior noise.

Also, when up against the noise of consistent nature, the noise-canceling feature certainly has it easy to produce anti waves to cancel out the exterior noise.

In the end, the reality is that no noise-canceling device exists that can cancel a hundred percent of the external noise though there sure are devices that do an excellent job at this. 

What is Active Noise Cancellation

What is Active Noise Cancellation

It might be the buzzword that almost all manufacturers use to highlight just how much more advanced their audio device is.

However, the basic working principle is the same in that there is an external mic whose task is to single out the steadiest noise source.

Underlying electronics then get to the job of producing an anti-wave to cancel it.

With the most omnipresent noise source taken care of, things are a lot quieter for the user.

However, ANC requires more elaborate electronics and a power source in the form of a physical battery for its working.

That makes only larger devices such as a headphone fit for implementing ANC tech and is impossible to be included in an earplug that is way smaller in comparison.

Are Noise-Canceling Earplugs Safe?

Are Noise-Canceling Earplugs Safe?

Well, so much for all the benefits it stands for, not all noise-canceling earplugs might be suitable for all.

Instead, some reported having a feeling of dizziness or disorientation from the use of noise-canceling headphones.

Some said they couldn’t simply use such earplugs as they tend to cause undue pressure on their eardrums and are hence highly uncomfortable.

Fortunately, manufacturers are all too aware of such earplugs’ ill effects and offer ways to modulate their effectiveness.

So, if there is too much discomfort from using the noise-canceling feature, reduce its power.

Or, in the worst-case scenario, turn it off, and you have an earplug similar to any other ordinary stuff sans the fancy noise-canceling feature.

However, the latter scenario where you can’t stand the noise-canceling feature and are forced to shut it off can be considered a total waste of the extra money you paid for.

Such a feature comes for a price premium over their ordinary counterpart, and if you can’t stand it, you’d be better off with earplugs sans the said feature.

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