I have had my Galaxy Note 8 since around 17 months without any problems, but since last one month or so, the phone has started giving out a mysterious sound - as if you are making a gentle tap with your finger nail onto a hard plastic, or a bit like the crackling sound we used to hear on old radios. Just gives out one tap/crackling sound at a time (not a series of it). It happens about a dozen times in a day.
The sound occurs completely at random, so impossible to record it, I am afraid.
It happens even when the phone is in silent mode, with the media volume turned off completely.
It occurs mostly when I am using WhatsApp or Facebook, but it has occured a few times when using a web browser too - this could be purely coincidental, though.
I am worried. Could it be the battery that's starting to go bad?? Or some spooky software running in the background?! Please help.