As a heads up since I've seen a few people ask about it, if you're getting a continuous clicking noise from Decker, that seems to be a bug in certain versions of SDL2. https://itch.io/t/5229926/decker-makes-constant-clicking-sound-on-one-of-my-comp...
Fixing it is likely up to your Linux distro in terms of updating to a newer version of SDL2 that fixes the bug, but in the meantime starting Decker from the command line with 'decker --no-audio' should disable audio and stop it bothering you at least.