If a floor begins to lower down producing looped sound and player restarts the map, that looped sound continue to play endlessly. Currently I am not sure will it play only in the same sector or everywhere (haven't got time for precise testing, maybe later).
This bug can be easily reproduced on fbase6.wad which comes with Doom Builder. When map starts press button to lower elevator, wait a second and restart game. Also you may check Doom 2 map 29 where is an elevator in the 1st room.
I was using OpenAL.