Spiral GanglionCochleaSpiral Ligament of CochleaCochlear ImplantsCochlear DuctCochlear NerveDeafnessOrgan of CortiTomography, Spiral ComputedEvoked Potentials, Auditory, Brain StemGangliaHair Cells, AuditoryLabyrinth Supporting CellsPresbycusisRetinal Ganglion CellsNeurotrophin 3Ganglia, SpinalHair Cells, Auditory, InnerBasal GangliaGanglia, SympatheticStria VascularisRound Window, EarGanglia, AutonomicHearingNeuronsHearing LossTrigeminal GanglionBrain-Derived Neurotrophic FactorEar, InnerHearing Loss, Sensorineural