Cochlear nonlinearity and second filter : possible mechanism and implications

We indicate that the directional sensitivity of the hair cell together with a directional distribution of frequency over the hair cells comprise a possible physiological basis for the second filter. Tuning disparity of the first and second filter denotes the difference in tuning frequency; at a given position x the tuning frequency of the first filter is ?CF, of the second CF, with ?-1. This accounts for the asymmetry in location of two-tone suppression areas. The compressive nonlinearity is described by a ?th law device with ?