So, updating everything: doesn't help. SteamVR / Devices / Reboot Vive headset = doesn't help. Changing audio devices back and forth (or fiddling Device Manager) doesn't help. Rebooting Windows may help, but sometimes even that doesn't help.
Surely there must be a quicker workaround (until the drivers are fixed)?
The problem sounds like sampling frequencies are messed up (trying to play back at double speed or so but then it syncs back to the correct rate, resulting in a horrible broken sound).