Terminal in Gnome 3: Disable audible bell, enable visual bell

Solution 1:

Disable audible bell and enable visual bell with:

gsettings set org.gnome.desktop.wm.preferences audible-bell false
gsettings set org.gnome.desktop.wm.preferences visual-bell true

and change the type of the visual bell if you don't need the fullscreen flash:

gsettings set org.gnome.desktop.wm.preferences visual-bell-type frame-flash

Options for visual-bell-type:

fullscreen-flash – causes a fullscreen white-black flash
frame-flash – causes the titlebar of the application which sent the bell signal to flash