I have no idea what's going on here. I'm getting massive frame drops (from over 100 to under 10 in some cases) and the culprit looks to be... the sound thread?

All I know is that the sound thread's usage surges hugely when these drops happen (see screenshots) and there aren't many sounds playing when it happens. I've had it seize up when there was very little audible happening.

I've attached a forced crash report and "before" (MC Debug 1) and "during" (MC Debug 2) screenshots.