EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.1

PE Spring,1999

25D

ORGAN / B.GOLD LECTURE 15

University of CaliforniaBerkeley

College of EngineeringDepartment of Electrical Engineering

and Computer Sciences

rofessors : N.Morgan / B.GoldE225D

Ear Physiology

Lecture 15

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.2

n

25D

ORGAN / B.GOLD LECTURE 15

Introduction : Anatomy - OK , Physiology - NOT OK.

- Anatomical Pathway

- Peripheral Auditory System

- Hair Cell Auditory Nerves

- Auditory Nerve

- Adaptation

- Synchrony- Non Linearities

- Two Tone Suppresio- Saturation- Masking- Combination Tones

- Block Diagram of Periphey

- Tuning

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.3

25D

ORGAN / B.GOLD LECTURE 15

Some Auditory Jargon.

afferent ascending nerve fibers

efferent descending nerve fibers

tonotopic Frequency selectivity vs. place.

{Bank of filters concept}

Malleus Incus Stapes Inner Ear

Innervate connect to

Cochlea Inner Ear

Middle Ear OssiclesOval Window of

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.4

nkey.

lls

25D

ORGAN / B.GOLD LECTURE 15

Table 14.1 : Cells in the Auditory Nuclei of the Mo

Central Auditory Nucleus Number of Ce

Cochlear Nuclei

Superior-Olivary Complex

Muclei of Lateral Lemniscus

Inferior Colliculus

Medial Geniculate Body Auditory Cortex

88,000

34,000

38,000

32,000

364,000

10,000,000(pars principalis)

- We are somewhat familier with cochlear nucleus.

- There is also work on auditory neurons in Cortex.

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.5

uditory Pathways

in with the Ear.

25D

ORGAN / B.GOLD LECTURE 15

Diagram of the A

linking the Bra

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.6

r ears are appproximate.

25D

ORGAN / B.GOLD LECTURE 15

Figure 14.3 : The Peripheral Auditory System. Boundaries between outer, middle, and inne

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.7

25D

ORGAN / B.GOLD LECTURE 15

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.8

25D

ORGAN / B.GOLD LECTURE 15

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.9

iagram of Peripheral

y System.

25D

ORGAN / B.GOLD LECTURE 15

Block D

Auditor

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.10

25D

ORGAN / B.GOLD LECTURE 15

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.11

Cochlea.

25D

ORGAN / B.GOLD LECTURE 15

Figure 14.7 : Drawing of the cross-section of the

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.12

lea.

25D

ORGAN / B.GOLD LECTURE 15

Figure 14.4 : Simplified Model of the Coch

EE 225D LECTURE ON EAR PHYSIOLOGY

N.MORGAN / B.GOLD LECTURE 15 15.13

Computer Model of Basilar-Membrane Displacement.

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.14

ce lls

25D

ORGAN / B.GOLD LECTURE 15

F igure 14.7 : Sketch of the inner and ou ter ha ir

in a cross-section o f the coch lea.

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.15

ilia open

ll, causing

lcium

s (Unknown)

channels in

epolarizing fiber.

uses action

vibrates.

ncrease)

ell.

25D

ORGAN / B.GOLD LECTURE 15

HAIR CELL (Pickles)

Ionic channels in stereoc

Potassium ions enter ce

Depolarization opens ca

Influx of calcium release

Neurotransmitter opens

Sodium flows into fiber, d

Depolarization of fiber ca

when basilar membrane

. depolarization (Voltage i

channels near base of c

neurotransmitter.

afferent nerve fiber.

potential (Spike).

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.16

25D

ORGAN / B.GOLD LECTURE 15

Properties of Auditory Nerves

- Adaptation

- Tuning

- Synchrony

- Non-Linear behavior Saturation

Combination- Masking

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.17

25D

ORGAN / B.GOLD LECTURE 15

Figure 14.9 : Adaptation by an auditory nerve.

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.18

r less randomly spaced

histogram

25D

ORGAN / B.GOLD LECTURE 15

spontaneous

spikes are more o

stimulus

post stimulus time

t2 t3t1

EE 2 LECTURE ON EAR PHYSIOLOGY

N.M 15.19

ditory Nerve Fibers.

74)

25D

ORGAN / B.GOLD LECTURE 15

Tuning Curves of Six. Au

(King & Moxon 19