In this paper the main emphasis is laid on presenting an up-to-date description of the relationships between stimulus-related cochlear potentials: cochlear microphonic (CM) and summating potential (SP) and the preceding mechanical events. To this end, CM and SP (both DIF and AVE SP) magnitude functions, obtained with the differential electrode technique, are shown from various turns of the guinea pig's cochlea as recorded at a constant stapes displacement. The similarity between these curves and corresponding basilar membrane displacement functions is considered. The influence upon CM recording of the distributed nature of the generators, as well as the presence of strong nonlinear effects is discussed.