how do you add it to your map?

Look through this thread and then find this point in your LUA:

Use the stuff from Rends's tutorial to add global sound instead of sound for an AT-ST. If you need more detailed help, ask again. I won't pretend to be a pro at this, though, as I have never tested it. :p

hmm, someone want to add this info to the Wiki?

alright I am in the process of trying this. I will post my results some time soon