You may find that sound no longer works in your QEMU guests after the October 22 upgrade to QEMU 9.1.1-1. Downgrading QEMU to the previous version, QEMU 9.1.0-2, solves the problem for me:
Arch attempted to fix the problem at their end with the release of QEMU 9.1.1-2:
However, this update did not fix the problem, so I have downgraded again to QEMU 9.1.0-2.
Meanwhile, the QEMU devs have not yet isolated the problem. So they plan to release QEMU 9.1.2 in about 10 days, which will essentially return users to the status quo ante of QEMU 9.1.0: