Electrocochleography (eCochG) is a neurophysiological technique used to assess cochlear and auditory nerve function by recording electrical potentials generated in response to sound stimuli. Since its inception in the mid-twentieth century, eCochG has evolved significantly in both methodology and clinical applications. Initially, extratympanic eCochG employed electrodes placed in the ear canal to measure cochlear potentials noninvasively, although this approach offered lower signal clarity. The development of transtympanic eCochG improved signal quality by positioning electrodes near the promontory, aiding in the diagnosis of conditions such as Ménière’s disease. However, its invasive nature limited widespread clinical adoption. With advancements in cochlear implants, intracochlear eCochG has emerged as a powerful tool for real-time monitoring of cochlear function. Early research in animal models paved the way for integrating eCochG into cochlear implants, enabling direct measurement of summating and action potentials. This approach helps optimize electrode placement, assess residual hearing, and improve implant outcomes. The historical transition from extratympanic to intracochlear eCochG reflects a shift toward more precise and clinically valuable techniques. Today, intracochlear eCochG continues to advance, enhancing auditory diagnostics and hearing preservation. As technology progresses, it holds promise for further refining cochlear implant programming and auditory rehabilitation.