User blog comment:JakePT/Arrival has Arrived/@comment-1691295-20110329133918/@comment-1221773-20110329134338

The Normandy sound issue probably isn't related to the DLC. I had the same problem a few weeks ago. I think it has something to do with how long you've had the game running. I remember it was during a particularly long session of ME2 that I first noticed the problem. The next day, everything was fine again.