Крутим колесо мышки при наведённом курсоре на значок в трее - громкость меняем.

[drugo]

You can install Volume². It will be the solution of Your problem 

hi
it doesn't work in wasapi exlusive mode , at least i have tried it without luck ,you?

[Choveka]

It works properly for me for both of WASAPI exclusive (Push) and (Event), but I'm on Windows 10 Pro x64.