<prompt> Cochlear basal turn dysplasia is known asMichel dysplasiaScheibe dysplasiaAlexander dysplasiaBing Schiebenmann dysplasia  <response>: Congenital malformations of the inner ear Complete labyrinthine aplasia Michel, Complete membranous labyrinthine dysplasia Siebenmann-Bing, Cochleosaccular dysplasia Scheibe, Cochlear basal turn dysplasia Alexander Alexander dysplasia : It affects only the basal turn of membranous cochlea. Thus only high frequencies are affected. Residual hearing is present in low frequencies and can be exploited by amplification with hearing aids. Ref : Diseases of ENT by Dhingra 6th edition Pgno : 115 