iphone speaker stuck in headphone mode

My iphone 5 (iOS 9.3.2) is not making any sounds except phone ring. I went to settings>sounds>ringers and alerts, and the phone ring it is audible when I slide the bar there.

When I go to adjust the volume with the botton on the side of the phone, I see the little bell icon appear on the screen and clearly it is adjusting for more or less volume, but that box says "headphones" above the bell symbol, which makes me think the phone is in headphones mode. I tried rebooting several times. (I do not have headphones plugged in)