Where is the most productive electrode placement for an ECochG?

The most productive electrode placement for an Electrocochleography (ECochG) is at the promontory of the cochlea. This location allows for optimal recording of the electrical potentials generated by the inner ear, particularly the cochlea, during sound stimulation. By placing the electrode at the promontory, which is the bony part of the cochlea located just medial to the tympanic membrane, the electrode can effectively capture the summation of the cochlear potentials, including the cochlear microphonic, summating potential, and action potentials of the auditory nerve.

In this location, the electrode is close to the sources of these electrical signals, producing a clearer and more robust recording than other sites. The external auditory canal, middle ear, and brainstem offer varying degrees of electrical signals but do not provide the same level of direct response from the cochlea, thus making the promontory placement superior for capturing the important components of ECochG readings.