iVol

iVol is a program you can use to adjust the sound volume of your computer in an extremely easy way. Just press your mouse wheel and scroll it up or down.

You do not even have to move your hand! In addition, it also supports Shift+Wheel as an alternative.
The program can display an on-screen volume level, and also allows you to switch between audio devices using Alt+Wheel.
Usage tips:
- Just press and scroll the mouse wheel. A volume indicator is shown to tell you how much the current volume is. You can disable the volume indicator while you are playing games.
- Alternatively, you can use SHIFT + Wheel UP/DOWN to adjust the volume as well.
- You can also change the current sound device whose volume will be adjusted by pressing ALT + Wheel UP/DOWN.
- Double click the mouse wheel to toggle the "Mute" status.
- While mouse is over the indicator,
- Right-click to switch to next device;
- Left-click to switch to previous device;
- Wheel Up/Down to adjust volume.