NAD C588ELECTRONIC SPEED CONTROL Having exact pitch (speed) is important, but human hearing is much more sensitive to momentary changes in speed which we express with the terms Wow and Flutter. As its name sounds, Wow is a slow cyclical speed variation. The most severe example is the sound of a severely warped record, where the stylus travels faster on the rising side of the warp and slower on the descending side, causing abrupt changes in musical pitch.