I installed Decker 1.58 on my very old potato laptop that runs Linux Lite (following Millie Squilly's instructions), a problem I have with it is that it makes a constant, very annoying clicking sound while it's running. Anyone have any idea what could be causing this.

Sounds similar to issue #78, which was traced to a regression in SDL2.

You can start Decker with the "--no-audio" flag to completely disable sound.