Sound Propagation in Dead Space

Firstly Dead Space is terrifying and its all down to the audio it's superb. However whilst playing the game i noticed a small problem with the sound propagation, watch the video and take note of the way the sound changes as the character moves away from the fire and into the other room. If you watch the video further the character moves back into the main room, again take note of the sound. The two changes occur at completely different places. This leads me to think that the sound changes are triggered by the door moving rather than using occlusion. this leads to some weird effects during the game.