1. II Acoustic Reality
II.2 (M Sept 18) Hearing with Ear and Brain

2. malleus
incus
stapes
semicircular channels
cochlea
ear drum
auricle
20-fold reinforcement
enters the upper (oval) window of cochlea
2.5 windings 30 mm length
1 cm2

3. 24‘000 hair cells oval window Corti organ tectorial membrane 1 mm
scala
media
tympani
vestibuli
auditory nerve
Reissner‘s membrane
perilymph
liquid
endolymph
liquid
inner hair cells
outer hair cells
basilar membrane
10-8 cm in 1/200 sec
24‘000 hair cells
30-50 stereo-
and
1 kino-ciliae

4. George von Békésy 1961,
Harvard U, Nobel prize
high frequencies
low frequencies
helicotrema
stapes
round
window

5. 4 major transformations of data!
colliculus inferior
nucleus cochlearis
gyri Heschl
corpus geniculatum mediale
30‘000 nerve „cables“
nuclei superiores olivae
nervus cochlearis

6. cat brain
multiple representation of
same pitch
low pitch
cochlea
high pitch