When you have different users, with different permissions for example Windows and Linux administrators. Right management: Linux administrators sees only info about Linux servers, items, triggers etc. and Windows administrators only about Windows servers, items, triggers etc. Both admin groups use Sound notifications (Monitoring - Triggers (Sound ON)) and both recieve sound notification in event when trigger goes on/off, even if they don't have a permission for it (no permission at all).
Admins group that doesn't have a permission only hears alarm setting off, but doesn't see issue (trigger). For them there is no information in Monitoring - Triggers about active triggers, but they still hear a sound.
For example if Triggers sets off on Windows server, Linux admin will be notified by sound, but he wouldn't be able to see event which caused alarm to go off. Windows admins will receive both - sound and information (in gui) about trigger.
This bug makes sound notification function worthless.