I get annoying sounds and vibrations when there is a missed call. Also I get beep sounds when I send a enquiry message to my mobile operator. Ex: *121#.
The sound when you start charging your phone, Connect USB ,send a enquiry to operator in 'Phone' application. I couldn't find a way to disable the sounds in settings of Stock OS.
Using 'Do Not Disturb' mode is the temporary solution I found.
It looks like you're new here. If you want to get involved, click one of these buttons!