Most odd game crashes ever seen

Summary -- games continue to run on automatic loops for some graphics and animations while the sound and any new instructions into the game environment stop. Graphics display no signs of corruption.

Detailed description --

Playing a game, usually one with a reasonable amount of sophistication (and demand on hardware), the sound will often stop.

What's really strange is what else happens when the sound stops. Any new instructions for the game fail to load. However, the graphics and whatever routines are running at the time of the freeze will continue to run.

For example, a turret firing from a bunker in a WW2 shooter continues to spray out bullets in a set pattern. But the sound stops, and all new movement inputs (both for the player and the AI) cease.

Sometimes during cutscenes, the whole thing will freeze except the animations (like water flowing) and, without sound, the subtitles will continue to stream.

A specific example of this is at the opening scene of Battlefield Bad Company. Your small team is on a boat heading into a Japanese POW camp and a mate is speaking with you.

The game will freeze the sounds and the boat will stop moving. But the smoke from my mates cigarette will billow onward, the water will bob the boat up and down, and the subtitles for the opening scene will continue to flow as if nothing has gone wrong.

There are no screen graphic corruptions.

This is not a game-specific event, but I've reproduced it in many games, even titles as benign as The Sims 3.

Often the freeze will recover after 30-60 seconds, and then re-freeze, until a total system crash occurs.

Any clue as to what is causing this?