The presence of low frequencies; technically, those in disc
reproduction caused by the record turntable (see EQUALIZATION).
More generally, the term refers to the presence of low
frequencies anywhere, as in, for instance, buildings with
forced-air ventilation or the interior of a quickly moving
automobile. See spectrum diagrams and sound examples under
INFRASONIC. Compare: BASS, HISS, HUM, WHITE NOISE, WOW. Sound
Example: Mechanical noise from ventilation equipment atop the
Buchanan Building, U.B.C., Vancouver.