how do i turn off sound and text notifications?

I find both the text and sound notifications very annoying. I do not play games or do anything other than work on this computer. When I unchecked the "show a notification" and "play a sound" boxes, the notifications and sounds do not turn off. I also prepared a 5 second sound file of silence and checked the "Play a Sound" and "use the following sound" boxes with the name of the silence in the required field. Nothing has worked. I don't like being disturbed when I work. I have done the checking and unchecking before restarting and also starting the computer up after a complete shut down.