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By Kaustubh on 6 November 2020
Noise is an unwanted sound causing a loud and unpleasant experience to the ears. Noise cancellation works by stopping these unwanted sounds from reaching the ears.
In this post, we are going to discuss the noise cancellation and how it is implemented.
How many types of noises are there?
We come across various sounds every day, some are audible and some are disturbing. Noises can be classified into the following types,
As the name indicates, these are the continuously generated noise signals, the receiver has no other option, but to to move far from them.
For example, the sounds generated in an engine room in a ship or the sound of the machinery in a factory, are continuous.
Those who work in those places have to take proper care to cover their ears, as the sounds may cause damage to their eardrum. The earplugs they use, provide the needed noise cancellation allowing them to focus on their work.
There may be some noises which are unwanted and not continuous, they come and go.
For example, the sound generated by the vehicles passing by when you are in a busy street is the non-continuous noise.
These noises are expected by the environment, surroundings and of course the time of the day, that are passing through. Proper preparation can make our escape from such noises.
The sudden noises are sounds created by dropping something on the floor or a sudden tyre burst which happen out of nowhere without any prior warning.
We can’t escape from them, they happen so fast and we won’t be aware of their occurrence before they happen.
Low-frequency noises are sounds that we come across in our day to day lives.
They are not clearly audible but create an impact. Some are soothing and pleasant, like the chirping of birds in the morning, they have such a relaxing effect on our ears.
But, some low-frequency sounds may interfere with the actual sound waves and cause interference. Noise cancellation works by totally removing these low-frequency noises.
Why is Noise cancellation needed?
When you are listening to your favourite music and suddenly some disturbing noises are happening in the background, and you can’t properly hear and you are failing to enjoy your music experience. What will you do?
In such circumstances, one will definitely increase the volume so as to concentrate on what is important to you.
What happens when you hear the sounds with more volume than needed is, we are increasing the pressure on our ears.
The Human ear is capable of hearing the sounds in a decibel range of 90.
More than 90db causes the permanent damage of your eardrum and this may result in the hearing loss also.
Let us see the decibel range and discuss further.
Noise puts extra pressure on the brain and ears causing headaches and stress.
Research has shown that exposure to sounds of range more than 90db of sound for more than 8 hours results in damage of eardrum.
And the exposure to noises which are more than 140db can cause permanent damage to the ear, leading to the hearing loss.
So, noise cancellation has gained interest over all these years. The headphones or earbuds’ brands are focussing on giving the ultimate music experience to the users providing the best bass and wire-free assistance.
They have come forward extending the convenience and comfort to the users to the next level by providing the noise cancellation.
How is noise cancellation implemented?
Noise, as we have discussed, is an unwanted addition to our original sound wave. They cause interference to the signals generated before they reach the receiver.
Noise control can be active or passive.
1.Active cancellation works by completely removing the noise signals. Noise cancellation works by targeting these unwanted low-frequency waves by creating the opposite waves neutralizing them.
2.Passive cancellation works by providing soundproofing with isolated materials so that the noise waves can not enter the environment. It just stops the noise but doesn’t remove the noise completely.
How does ANC work?
ANC, Active Noise Cancellation is also known as Noise Reduction, works by creating sound waves which are 180 degrees phase shift with the noise waves.
Consider the below diagram, we have shown the noise along with the interference and how the interference is removed.
The noise-cancelling headphones have an external microphone, which scans the incoming sound for the low-frequency interferences.
Once it finds such signals it generates an opposite signal which is 180 degrees out of phase along with the incoming signal.
As shown in the diagram, the noise signal and the opposite signal superimpose each other producing the silence.
When the noise and its phase-invert collide with each other, they get neutralized giving a noise-free experience.
What are the benefits of Noise cancellation?
1.The first and foremost benefit is, noise-cancelling brings peace to our lives.
Many people nowadays are simply using the noise-cancelling headphones and earbuds for sleeping.
simply put on the noise-cancelling headphones and stay in silence for some time, and see how refreshing you feel. It makes you know more about yourself and gives a lot of relaxation.
2.Noise cancelling headphones are a blessing to people who travel a lot. Travelling made easy and a lot comfortable with them.
Now boring journeys are made enjoyable and manageable.
3.Noise cancellation makes you concentrate on what you are doing.
They make us focus more on the jobs which need our full attention.
During this pandemic, most of the people are working from home and it is always a tough task to work in the middle of so many disturbances.
In those situations, the noise-cancelling equipment helps us the most.
4.Noise cancellation protects your ears from noise pollution caused by excessively loud surroundings.
They make you feel comfortable and quiet even in crowded environments.
Noise cancellation removes stress and brings quality in your life.
What are the drawbacks of Noise cancellation?
The following are some of the drawbacks of Noise cancellation.
1.The first and the foremost is the price. Every thing comes with a price and the noise-cancelling features are not an exception.
They are expensive compared to traditional headphones.
2.Noise cancellation works by sending inverted phase mirror waves, which requires more power. They need power to be supplied from a USB port occasionally.
3.Noise cancellation creates pressure in the ears, some people say they faced some discomfort and Dizziness when putting the noise-cancelling headphones for a longer period of time.
Do not use the headphones or earbuds for too long to experience pain in ears and headaches.
4.Finally, noise cancellation devices are made to introduce comfort to our lives, not to cut out us from being social. Some people are getting lost in their own world and fail to mingle with the other around them. This is definitely one of the serious drawbacks.
Excessive use of technology has more side effects than benefits. Limit your usage of noise cancellation devices to times when they are needed the most and make your presence valuable to the family.