EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.1 University of CaliforniaBerkeleyCollege of EngineeringDepartment of Electrical Engineeringand Computer SciencesProfessors : N.Morgan / B.GoldEE225D Spring,1999Ear Physiology Lecture 15EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.2Introduction :Anatomy - OK , Physiology - NOT OK.- Anatomical Pathway- Peripheral Auditory System- Hair Cell Auditory Nerves- Auditory Nerve- Adaptation- Synchrony- Non Linearities- Two Tone Suppresion- Saturation- Masking- Combination Tones- Block Diagram of Periphey- TuningEE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.3Some Auditory Jargon.afferent ascending nerve fibersefferent descending nerve fiberstonotopic Frequency selectivity vs. place.{Bank of filters concept}Malleus Incus Stapes Inner EarInnervate connect to Cochlea Inner EarMiddle Ear OssiclesOval Window ofEE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.4Table 14.1 : Cells in the Auditory Nuclei of the Monkey.Central Auditory Nucleus Number of CellsCochlear NucleiSuperior-Olivary ComplexMuclei of Lateral LemniscusInferior ColliculusMedial Geniculate Body Auditory Cortex88,00034,00038,00032,000364,00010,000,000(pars principalis)- We are somewhat familier with cochlear nucleus.- There is also work on auditory neurons in Cortex.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.5Diagram of the Auditory Pathwayslinking the Brain with the Ear.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.6Figure 14.3 : The Peripheral Auditory System. Boundaries between outer, middle, and inner ears are appproximate.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.7EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.8EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.9Block Diagram of Peripheral Auditory System.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.10EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.11Figure 14.7 : Drawing of the cross-section of the Cochlea.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.12Figure 14.4 : Simplified Model of the Cochlea.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.13Computer Model of Basilar-Membrane Displacement.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.14Figure 14.7 : Sketch of the inner and outer hair cells in a cross-section of the cochlea.EE 225D LECTURE ON EAR PHYSIOLOGYN.MORGAN / B.GOLD LECTURE 15 15.15HAIR CELL (Pickles)Ionic channels in stereocilia open Potassium ions enter cell, causing Depolarization opens calcium Influx of calcium releases (Unknown) Neurotransmitter opens channels in Sodium flows into fiber, depolarizing fiber.Depolarization of fiber causes action when basilar membrane vibrates. .depolarization (Voltage increase)channels near base of cell. neurotransmitter. afferent nerve fiber. potential (Spike).EE 225D