Volume control pops up on the monitor randomly

I have a late 2013 Mac Pro with a 27" and a 4k NEC spectraview monitors. Randomly as I am clicking, the little window showing the volume level pops up on the screen for a few seconds. Doesn't seem to affect anything but it is annoying. The input to audio is a logitech camera and the output is a set of bose usb speakers

Has anyone experienced this?

thanks,

mike