Bubble sound recurring, so annoying.

[Tomuka]

Recently I got so mad with this bubble sound that occurs while I am on any app.

The simple solution is your NFC in your setting is turned on and it will try to search other devices nearby, turn off this button and get rid of this sound and interruption.

 

[B. Diddy]

Welcome to Android Central, and thanks for the tip! I believe that tone plays when the phone's NFC chip detects something else nearby with an NFC chip (like a credit card or ID card). This can happen if you have a wallet-style case containing those kinds of cards.