This morning when I took my phone off of charge I noticed that I would get a text and it would vibrate but not give me an audible notification. When I open and close menu's I can hear the click that is associated with opening and closing menus. My phone will ring when called. I went into the sounds menu, opened notifications, when I make a different choice from the default sound I don't get a preview of the sound at all. When I go into ringtone and select a different ringtone, I do get a preview of the new ringtone. This is definitely isolated to notifications which makes me wonder why and how to fix it. I can't find a volume for notifications only.