The relationship between the parameters of pure‐tone acoustic stimuli and those of the cochlear microphonics (CM) and summating potentials (SP) was studied for measurements from scala media in each of the four turns of the guinea‐pig cochlea. For each turn similarities in the shapes of the input‐output functions over a wide range of frequencies permitted adequate quantitative description of these functions by a single third‐degree polynomial equation. Therefore, the properties of both cochlear potentials (CM and SP) can be described by a nonlinear transfer curve over the specified frequency range. These results imply the SP should not be regarded as being generated by a process different from the CM but as an expression of the nonlinear characteristics of the generator of cochlear potentials. At frequencies where the measuring electrode is near the peak of the mechanical traveling wave envelope, the transfer curve no longer described the cochlear potentials. Calculations based upon phase measurements and upon theoretical considerations indicate that this is due to interference effects from the out‐of‐phase generators in the vicinity of the electrode.