Galaxy S II : no sound and icon

[Chubs22]

I have an icon in the upper left of my Samsung Galaxy S II that looks like a man in a circle. So, like a circle with a line if the line has a head. When I have this icon on my phone; i have no sound notifications for texts or Facebook. So, I never know when someone is texting me or trying to chat with me on Facebook.

I have tried turning it on and off, checked the Hangouts and the SMS is off, removed the battery and put it back in.

Please help!