To give some sort of respectability to this crude hack, an idea was proposed that "the human hearing is most sensitive to speed variation in this frequency range". Interestingly, the psychoacoustic study on the subject that everyone cites was done after
the introduction of weighting in measuring equipment (Hisao Sakai, "Perceptibility of Wow and Flutter", JAES Volume 18 Issue 3 pp. 290-298; June 1970
.) It cannot stand up to even cursory scrutiny, as Ampex's engineer John G. McKnight pointed out
as soon as it was published. To me, the whole perception weighting idea feels like a post factum fabrication.
But the lure of reducing a complex behaviour to one easily measurable number was too strong. And, besides, there were no tools to extract more meaningful momentary speed data.