Volume randomly mutes itself in upper left corner

[llamapoo]

I'm on a desktop running Windows 10, 2 old Samsung monitors, Logitech G930 headphones, and an old Das Keyboard. I've searched a bunch and can't seem to find a specific answer to this weird problem. Every once in a while, more so in the past 48 hours, my sound will randomly get muted. The volume icon in the task bar gets the X in it, but more importantly there's a volume bar that I've never seen and have no idea what it is in the upper left hand corner. (http://i.imgur.com/V6n1uUK.jpg) The place I got that photo from says he's using a laptop and he can change the volume using function keys, which I get, but I'm not on a laptop.. Why is my desktop muting my volume from there, and how do I make it stop. Is it malware? I've run Malwarebytes completely and nothing comes up. Nothing I have mutes sound like that (keyboard/mouse/monitor)

 

[little_me]

same volume icon also appears if you use keyboard volume up/down media keys. (top left corner, as you said)
If your keyboard has said keys and you are not pressing them when it happens, it might be that said old keyboard is at it's life's end.
Some of das keyboards have fn+F button controls for next/prev/pause/stop/volume+/-/mute and some have a wheel.

Edit: I fail at reading, you said you don't have anything like that on keyboard/mouse/monitor, leaving only other option as some weird global hotkey/autohotkey script, possibly.

 

[llamapoo]

same volume icon also appears if you use keyboard volume up/down media keys. (top left corner, as you said)
If your keyboard has said keys and you are not pressing them when it happens, it might be that said old keyboard is at it's life's end.
Some of das keyboards have fn+F button controls for next/prev/pause/stop/volume+/-/mute and some have a wheel.

Edit: I fail at reading, you said you don't have anything like that on keyboard/mouse/monitor, leaving only other option as some weird global hotkey/autohotkey script, possibly.

I can literally just be watching youtube videos, hands off the keys, not touching the mouse, and the volume mutes itself. I have absolutely no idea why it's doing it, and why it's doing more frequently the past couple days.