When u get a private message,u only know it if u happen to look up at ur screen.But while posting you tend to forget to keep checkin if u got a new private message.
So what i suggest is,that when you get a new private message you here a certain sound.
Try using a subject that relates to the topic at hand e.g. "Private messages sound"
People are notified of private messages in these ways;
1. Link on the top right of the forum 2. Private messages box on main page of the forum 3. They receive an email to tell them they have a new private message
There are no plans to add sound to the ways users are notified. Personally I would consider that an invasion of my privacy. What would happen if the user had their speakers turned off ?