Thanks for replying, Jack! I've updated to beta 2.10-08, tried again, and do not get the overpowering sine wave repeating. So it already seems to fix the issue?
A small point btw: I think it's a design... frustration to make the player wait for the recording to finish before the hatch opens, IMHO it should open and the recording should play at the same time. Let the player decide if they want to stay and listen (e.g. first time players).