How to COMPLETELY turn off system beep sounds forever for good for real

I use Nautilus to explore my files. I use a Debian-based OS with KDE Plasma 5. I use the keyboard a lot. When I press the key up when navigating files, if I'm already at the extremity of the list of files, Nautilus sends a big system beep which I will hear at 100% volume through my headphones. My reaction is comparable to getting electrified. I have placed the following lines in ~/.bashrc for the sudo (root) user and for my regular desktop user: # Turn off system beep in console: xset b off xset b 0 0 0 However, despite the beep going away from some places in the OS (such as erasing an empty line in the gnome-terminal), it's still in Nautilus. I believe it's because Nautilus doesn't source any of the .bashrc or because it ignores the xset commands. How do I fix this? What I need might be at a deeper level than the .bashrc, some file that is executed by everything, but which can still control the sound. Otherwise, disabling the sound another way or replacing it could be interesting.