The console (also called a control board) is the source of linkage between all music equipment, the microphone, in-studio monitors, out-going volumes, and is the key element in keeping any in-studio processes running smoothly. It has a row of buttons which control the sources that go out across the air waves, where those sources go, and for previewing material. There are also faders which control the levels of sources. Adjust the faders to keep the console VU meters peaking, but not exceeding, "0" or "Unity Gain". Most of the level controls have been calibrated to work with the knob pointers at the diamonds or "0". Sometimes the level must be set considerably higher or lower to achieve correct VU meter levels - levels too low create noise in the signal, too high cause distortion. Announcers should constantly adjust audio levels as needed.