I have that sometimes, where is downloads the same doom sound effects etc. To be honest, I don't know what it is or why, but for clarification, it doesn't seem to be the map or the end of map music, but more like the "rampage" sound effects and such.
Sorry I cant help you further. Untill someone comes on that knows more about it, google is your friend. I don't have that problem at the moment, but I have previously.