Active Noise Cancellation: All You Need to Know About This Technology

The world is so full of sounds, both wanted and unwanted. But somehow the more we want to enjoy those wanted ones, the more those unwanted noises interfere.

What do we do?

As a result, we tend to be more creative in thinking about how to deal with noise. There are many ways to categorize that “battle” against noise. For example, active and passive ways. Speaking of active noise cancellation, let’s give a better look at what it is.

active noise cancellation

What is active noise cancellation?

You are certainly familiar with the proverb “when you can’t beat them, join them”. Using that very logic, that’s exactly how things work in active noise cancellation.

Active noise cancellation is a method where you use one sound to reduce another. So, when you want to reduce the unwanted one, you add a second sound specifically which is specifically designed to cancel the first one. This method is also known as active noise reduction.

Though using more sounds to reduce the existing the ones sounds silly that bother you, there’s a special technology behind it.

How does active noise cancellation work?

To have this fantastic technology explained it its easiest and best, I will take headphones as an example. The ones that feature this technology have some additional components comparing to the ordinary ones.

Here are the features listed and explained:

  • Microphone, which is inside the earcup, detects the sound which passive cancelation fails to fight.
  • Noise-cancelling circuity, also placed in earcup, receive the input sent by the microphone. The role of this part is to define the sound, or to be precise, its frequency and amplitude. When that’s done, an “anti-sound” is created. That sound, or to be precise, the wave is 180 degrees out of phase with the ambient noise.
  • Speakers combine the sound and “anti-sound” by using the second one to “erase” the unwanted sound without affecting the desired sounds.
  • battery is what powers the whole technology. That’s where active and passive noise reduction differ from each other, as you need the energy to power this technology.

As you can see, this amazing technology works in quite a simple yet powerful way. This phenomenon where you use one sound to destroy another one is known as destructive interference.

noise-cancelling-hearing-protection-devices

As a result of this process, you get a pure desired sound delivered to the ears of a listener. Speaking in decibels, this technology can reduce the noise up to 20dB. Taking overall environmental noise, that’s blocking about 70% of unwanted sounds. That’s certainly a significant thing.

The difference between active and passive noise cancellation

Now that we are familiar with the technology behind active noise cancelling, let’s see how the passive cancellation works! We can also use headphones as an example.

As there’s a technology behind active noise reduction, passive noise reduction requires no technology at all. The secret is in the design of the headphones themselves, as well as the materials for earcups.

All it takes is ear insulation! Yeah, that sounds scary, but it’s actually really simple. And not scary at all! You have two different types of headphones which work well for this purpose.

One type is those with large earcups covering the entire ear. They offer significant protection against ambient noise, sometimes even up to 70%.

Another type of these headphones is in-ear headphones. However, no matter how good in terms of quality these ones can be, still are not as reliable as over-head ones.

Do Noise Canceling Headphones Protect Hearing

It’s important to mention that active and passive cancellation do not necessarily include each other. While practically all types of headphones offer some sort of passive noise reduction, not all of them feature active noise cancellation technology. Speaking of, if you compare these two technologies, passive one is indeed a cheaper one, as there are no additional features.

Passive noise reduction works with frequencies above 1kHz but is limited at that point. On the other hand, active noise cancellation covers a wider range of frequencies.

To conclude, active is about technology whereas passive refers to design itself.

Where can we apply active noise cancellation technology?

As said many times, noise is everywhere around us, which is why an overall solution is necessary. Finding a quiet place or a quiet moment is hard these days. I took headphones as a practical example to explain how noise cancelling technology works, but there are actually many fields where it works.

  • There are special devices which are excellent in dealing with all the noises you can hear at home on daily basis. By this, I mean all the sounds coming from numerous appliances that surround us. Reducing these sounds will have a positive impact on our health. Besides leading to hearing loss, noise increases the level of stress as well as blood pressure and heart rate. In longer terms, this leads to severe health issues, which is why is very essential that we transform our home into a quiet and stress-free sanctuary.
  • As we spend a significant part of our day in cars, reducing all the noise coming from the engine itself, the tires, the road, and the wind is of vital importance. The same goes for all types of transportation, as many people use buses, metros, trains etc on daily basis. I have already pointed out all the health benefits of reducing unwanted noise.
  • There’s practically no quiet workplace in the world, as even a single computer creates some sort of annoying sounds. Even though you cannot deaden all the noise that surrounds us, still you can minimize its impact. A quieter workplace leads to increased productivity and less work-related stress.

As you can see, it covers every aspect of our life- home, transportation, and work. Reducing a decibel by decibel here and there, we can make a significant change. Even though we may not instantly hear the difference at some bigger level particularly when speaking of industrial noise, still as the time goes by, there will be many positive changes.

You will feel less stressed, and in this world full of stressful situations, is there more to ask for?

Final thoughts on active noise cancellation 

As you can see, this technology is very simple but does the magic.

Reading all the positive aspects of this fantastic technology, you can’t help wondering:

“Are there any negative aspects?”

Let’s take headphones as an example one more. Some people say that this technology compromises the quality of sound by muffling it. Some of the users experienced a slight change in air pressure.

However, despite these two, once you get the chance to see (or HEAR) how this technology in headphones work, you will never go back to ordinary ones.

do-noise-cancelling-headphones-damage-hearing

Now that you know all the positive aspects of noise cancellation, start making changes in your life. By that, I mean active ones. You will all agree that less noise means less stress. That leads to a better quality of life and overall health.

As you can see, you can apply active noise cancelation in every single aspect of our life, so start fighting the unwanted sound as soon as possible.

If you have any experiences with this technology, feel free to share them with me and other readers.