AbstractA new technique for the study of the inner ear is described. Cochleae are fixed, dehydrated and infiltrated with plastic while their bony walls are intact except for small holes at the third turn and near the round window. After the plastic polymerizes, the cochlear bone is removed so that half turns of cochlear duct can be separated from the modiolus. These specimens are re‐embedded in a thin layer of plastic after trimming so that their basilar membrane sides lie close to the surface of the plastic layer.Using phase contrast microscopy, the entire organ of Corti is examined by focusing through the surface of the plastic and through the specimens from the basilar membrane up to the tectorial membrane.Segments of organ of Corti containing small lesions are divided in such a way that cross‐sections of those areas for study by light and electron microscopy are obtained readily using an ultrot