Fig. 1

Schematic illustration of the electrode-to-modiolus distance (EMD) and angular depth of insertion (aDOI) to be measured. Applying the cochlear view, EMD was measured from the center of the modiolus “M” (helicotrema) to the center of an electrode contact “E”. A line from the round window “RW” through the modiolus to the lateral wall of the cochlear was the reference for measuring aDOI