VU stands for Volume Unit. This varies from PPM (
Peak Program Meters) in that a VU
meter displays the
average volume level of an audio signal.
PPM is measuring the
peak amplitude, which is the maximum volume of a signal, VU measures the
average volume. VU gives a
better idea of total power output.
Of Montreal- "Still I only feel alright when the vu’s flashing bombs going off in my head"