How can I set my notification sound to a custom sound?

A

AC Question

I just got a galaxy s5 and can not figure out how to set my notification (not ringtone) sound to a custom sound. There does not appear to be a option in the notifications menu to ADD a sound like there is for ringtones. I tried to under contacts and it goes back to the same menu where I cant add one. I dont know how to copy from ringtones to notification sounds as was suggested in one forum.