Not saying that you don't have an issue but it's highly unlikely that a sound mod would do that. I've installed and uninstalled Fonseker mods countless times and never had issues with graphics. Is it possible that there was a Windows update since you installed the mod? Also, would be a good idea to post your system specs and while you're at it check your GPU and CPU temps while in game, excessive heat can often cause graphics issues.
Postscript: If you haven't already done so you should also post the issue over at the official forums so both Fonseker and Kunos are aware, just incase you've found a legitimate bug.