<https://wiki.ubuntu.com/SoundMenu#Title>: "...when the pointer is over the title, whether the menu is open or not, clicking a mousewheel up or down should increase or decrease the volume..."
<https:/ /wiki.ubuntu. com/SoundMenu# Title>: "...when the pointer is over the title, whether the menu is open or not, clicking a mousewheel up or down should increase or decrease the volume..."