I do not own the game for now but my advise should be change the IRQ and DMA to different values under the soundblaster configuation to test. Also keep in mind that these values need to be the same in the game config and in the *.conf dosbox file.

Greetings

Thanks for your help but I found the problem.
It was an error in the Dosbox configuration file for the game. The dosbox_fs.conf file make Dosbox emulates a Soundblaster Pro but the game don't detect it because it is an incompatible sound card. On the sbtype line, you must change sbpro for sb16. Like this:

BEFORE

#sbtype=sb16
sbtype=sbpro

AFTER

#sbtype=sb16
sbtype=sb16

And there it is! The digital sounds work like a charm.
I hope this can help if anyone has the same problem like me.

Platov, thank you so much, you are a genius! I was trying to kick around the sound config in DOSBOX with soundsetup.exe, but this right here fixed my problem. I will send this in to GOG support, as I had a ticket in with them about this issue. I'm sure this will help a lot of people who buy the game. :)

Thank you again!

I am glad to help. :)

Has anyone had any luck with this fix after applying the German language patch from compiware?

It works perfectly for GOG's English version for me, too. After setting soundblaster type to sb16 I can hear digital sounds, menu clicks etc.

But after installing the patch for playing in German setting sbtype to sb16 doesn't help anymore and the sounds remain gone. I tried to experiment changing IRQ and DMA settings of the blaster emulation, but no luck so far.