  Prestin (SLC26A5), a protein essential for the sensitivity of the mammalian
ear, was so named from \emph{presto}. The assumption was that this membrane
protein supports fast movement of outer hair cells (OHCs) that matches the
mammalian hearing range, up to 20 kHz in general and beyond, depending on the
species. \emph{In vitro} data from isolated OHCs appeared to be consistent with
such frequencies. However, some recent reports cast doubts on this assumption,
suggesting that the intrinsic transition rates of this protein are much lower,
about 3 kHz for guinea pigs, not covering the auditory frequency range of the
animal. Recent \emph{in vivo} data also show that the amplitude of OHC motion
rolls off well below the best frequency of the location. The present report
examines whether or not these resent observations are compatible with the
physiological function of OHCs by using simple piezoelectric models.
