Morphological organization of an inner hair cell (IHC). Hair cell diagram showing the USH1 protein network essential for mechanoelectrical transduction (upper inset). At the synaptic region the protein otoferlin, the glutamate transporter (VGLUT3), clarin, harmonin, CDHR23, and CDHR15 involved in hair cell synaptic transmission (bottom inset). “?”, the presence of CDHR23 and CDHR15 at the ribbon synapses is still debatable.