Objective Announcer is a simple little addon that announces completed quest objectives to yourself, party, raid, guild or officers, as they are completed, and may include a quest link and additional quest info. It can also be set only to announce quest completion. Now has sound effects for your’s and your party and raid member’s announcements. And more, try it and see for yourself.

Type /oa or /obja to access options, or simply go to the interface options menu.