fluctuations de vitesse

OBS: Dans le domaine des audiofréquences, les fluctuations lentes (de 0,1 à 10 hertz) sont appelées pleurage, et les fluctuations rapides (au-delà de 10 hertz) sont appelées scintillement.
CONT: [Le] moteur [de la table de lecture TD 126 MKIII] a sa vitesse de rotation commandée électroniquement complétée par un circuit d'asservissement dit APC [...] qui compense automatiquement les variations de vitesses mais aussi les éventuels freinages extérieurs tels que ceux provoqués par un balai dépoussiéreur.

CONT: No capstan drive system is perfect and ... this will give rise to tape speed variations that affect the playback quality of music. ... Such speed changes are called wow and flutter.
CONT: Flutter is any deviation in frequency in reproduced sound from the original frequency: it usually results from nonuniform motion of the recording medium during recording, duplication or reproduction.
OBS: While the term ""flutter"" is normally limited to designating higher rates of speed variation, it is often generalized to include both wow and (high speed) flutter, as in TRAUD, 1969, p. 656. In addition, ""speed variations"" or ""flutter"" (in the generalized sense) could be used to refer to ""drift"", which is ""a random rate close to zero hertz"" (cf. GRAEL, 1977, p. 284).