Electrocochleography (Ecog) is an electrophysiological technique that focuses on wave I of auditory brainstem responses (ABRs) detects others electrical potentials generated by the cochlea. It provides an objective tool for assessing inner ear function. The equipment is the same as that used for ABRs, with a few minor adjustments to parameters, equipment, and placement of the active electrode. Clinical indications for Ecog are becoming increasingly widespread from the diagnosis of auditory neuropathies, endocochlear hydrops, monitoring changes in intracranial pressure, evaluation of superior semicircular canal dehiscence as well as intraoperative cochlear monitoring. Ecog is now an indispensable tool in audiological and electrophysiological practices. It highlights physiological mechanisms and improves our understanding of different pathological entities.