The cochlear microphonic (CM) is one of the electrical signals generated by the human ear in response to sound stimulus. Difficulty in recording this signal and inadequate understanding of its origin have restricted its use for human auditory research. Modelling can help to improve our understanding of this signal. In this paper, an electromechanical model for the generation of the cochlear microphonic is proposed. The results of the model can also explain discrepancies between the basilar membrane and CM tuning curves.