This blog post will explain how to disable audio in a qemu guest machine. Whenever a guest operating is used as a server, it is usually booted into console mode. It would be pointless to have a sound card enabled when there is no application that needs sound input and output. In order to disable sound, use the statement -audiodev none,id=none,driver=none in the command line arguments.
qemu-system-x86_64 -M q35 -m 2G -hda debian-12.2.0-amd64-DVD-1.qcow2 -usbdevice tablet -audiodev none,id=none,driver=none
The Windows version of QEMU was used for writing this blog post.