How Headphone cancel noises?

The Headphone microphone picks up the low-frequency noise and neutralises it before it reaches the ear. 

Which noise cancellation is better Active or Passive?

If all you want to do with your earbud is to block out ambient noise active noise cancelling earbuds will be a fine choice. Especially when you are not listening to music. Passive noise isolation is better for your hearing overall. This is because active noise cancellation neutralizes outside noise by creating an equal and opposite noise.

Does noise cancellation hurt ear?

If you are dealing with a noisy environment noise cancellation earphone will help protect your hearing. There is a possibility that you may listen to a slight hissing sound when you turn on active noise cancellation earphone for some people it may be irritating and may also result in dizziness.

Do noise cancelling Headphones work on calls?

Yes, Noise cancelling Headphones protect the users from the surrounding noise but it does not apply to the receiver of the call.

Does noise cancellation drain battery?

Yes, noise cancelling Headphones use 20 to 30 percent more power in noisy environment. So, it is better to choose ANC Headphones that have naturally long battery life.