Plays a built-in WoW sound when you cast Psychic Scream. Uses your "Master" volume setting.
demo (listen): http://www.youtube.com/watch?v=5OTI2kDlRzo
There are 9 scream sounds by default, but you can add more to the list in the lua file.
This addon is just over 1 KB in size, and its innards do not load for non-priesties.