How to avoid sound notification upon plugging in hardware

That would make sense. However, I have it unselected and the chosen (predefined) sound there does not correspond to the ones I’m hearing when plugging/unplugging a usb disk, for example:

However, when I listen to the chosen (predefined) sounds for these events in the system messages/notifications(?), they do correspond. But: I had them unselected and even then I hear the sounds. So it seems that for some reason my selection is not respected.