On one map (tibetan terror mission, a long map divided in two by a building/wall, with landing craft on one side and UFO on another), when I approach the tail end of the UFO (engines/airlocks area), some humming/growling sound plays even when I have sound/music volume set to zero.
I always play with sound off, so had quite a fun time trying to figure out WTF the noise is, the game being the last suspect
