Random Beep sound while on an outgoing call

[Android Central Question]

Hi,
I am using Nokia 3 Android v 7.1.1
Whenever I call someone I hear weird beep sound (randomly) which is really annoying and scary.
I have done reset and gone through many things to get rid of it but failed.
Please help me out.

 

[Tim1954]

You may have a call timer turned on?