Blink title and play sound when you receive a PM. OBS, works only by detecting if you have unread PM's so will not work when you are in a chat.
This script plays a sound and changes the title of the page to notify that you have received a PM. The notification only works when you have unread PM's, not if the PM chat is active/visible. So to get notifications when you are away from the page, make sure you are in the public chat. Also, some browsers don't play sound until the page have been activated once. Might also be a good idea to deactivate automatic hibernation of inactive tabs to make sure you get the notification. It's been mainly tested with Vivaldi and it works well.
