The cause is a missing vm-sound-ALSA.so module in /usr/lib/squeak/3.9-8/
The work around is to restore the module by hand.
Or to copy the entire /usr/lib/squeak/3.9-8/to somewhere easier to change.
Restore the module.
Add the path to the launchers invocation
via a squeak -plugins /home/myDir/mySqVmPlugins/ for example.