HP Pavilion dv4-2116tx Entertainment Notebook PC - Manual (Page 79)

Button Function
Settings Press to display system information. The button may also be used to display settings
menus for some multimedia software.
Volume down Press the button to decrease speaker volume.
Mute ● Press the button to mute speaker volume.
● If the volume is muted, press the button to restore speaker volume.
Volume up Press the button to increase speaker volume.
Button quick reference 67