Why is my volume slider popping up constantly?

A

AC Question

volume slider popping up constantly

Ever since the update on my HTC One....my volume slider control CONSTANTLY pops up on my screen and the volume adjusts itself. I will turn it back down and it goes back up automatically. This is so irritating!! When I am trying to send text messages, get on fb, look at the internet etc....this volume slider pops up on my screen and prohibits me from seeing anything and I can't close it out. I have restarted my phone a gazillion times and that hasn't helped. What can I do??? Thanks!