Loss of all sounds when ATC is on

I am using FSX on my laptop while deployed overseas in Afghanistan, not the best arrangement, but one I have to use. When ATC of any sort from ATIS or Center or any entity speaks, I lose my engine noises and every other sound associated with the aircraft. If I pause the game, the sound comes back, but we know that the sounds should blend. I am using headphones, is that an issue? It should not be in my mind.