I work for an IT helpdesk and sometimes I need to be able to either mute or turn the volume down on a meeting I'm in so I can answer the phone. As of now, there is only a Device volume slider in the desktop app (which I only have access to on my remote workstation, not my personal desktop).

I'm able to accomplish this by turning down the master volume on my computer but I speak to my clients by using a Vonage app on my desktop and turning the Master Volume down or muting it disallows me to hear them. Based on all of Volume Control requests spanning hundreds of pages I must say it's really sad that nothing has been done to implement some sort of volume controls.