The monitor output is the level of audio you hear when editing. This is controlled by the Audio tool, which you access by clicking the Audio Tool icon in the Liquid Edition taskbar (Figure 7.43).
Figure 7.43. The Audio tool with Extended dialog open.
You control the output via the sliders, which you can lock together by clicking the Lock button at the bottom of Audio tool.
It is important to remember that adjusting the volume here does not place keyframes on the Timeline, nor does it alter the final output volume of your project. You simply use it to adjust the playback level of the Timeline while you are editing.