To silence incoming calls and notifications, cover the screen with your hand.
Here's how to disable smart sound on Vivo Y53:
Step 1: Go to 'Settings' and select 'Smart motion control'.

Select 'Smart motion control'.
Step 2: Choose 'Smart calling'.

Choose 'Smart calling'.
Step 3: Turn on 'Disable smart sound'.

Turn on 'Disable smart sound'.
With that, your setup process is complete. Wishing you all success.
