The I/O function of the 'cascade of asymmetric resonators with fast-acting compression' (CARFAC) modelis calculated by the RMS of the out in response tones at intensities from 10 to 100 dB SPL at the CFs of 0.5, 1, 2 and 4 kHz. The nonlinear compressive shape of the I/O function represents the cochlear mechanical compression.