3d sound flag not working?

I found a sound in war3 that i wanted to use and it had no 3d sound flag option. it was greyed out so i exported the wav file and opened it up in my 3rd party sound editor and converted it to mp3 and it played great.. then i imported it to war3 and it now lets me set a 3d sound flag to the new file.. but i'm not hearing it in game.

i've imported many sounds before but i dont understand this one. how do i make it so that war3 will accept it?