I have set the “Sound theme” to “No sounds”, yet I still hear those irritating sound when deleting files.
You could try installing dconf-editor (if not already installed).
:~ sudo apt install dconf-editor
Open dconf-editor. Browse to
org/gnome/desktop/sound
On the right, unclick event-sounds.
Unfortunately it did not work.
Sound Preferences
Set alert volume to mute.
im glad you found a fix