Still having this issue:
My version numbers are the same as https://www.whonix.org/wiki/KVM#Debian_stable (click expand and scroll down to check version numbers).
<pre> <sound model='ich6'> </pre>
<pre> <sound model='ac97'> </pre>
But there are 2 more debian stable related issues, that I will post in separate threads. So maybe we don’t have to make this change, but can fix the root of this issue.