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Simulation of a Cochlear Model as a Descriptive Tool for
Normal and Abnormal Auditory Functioning
Miriam Furst-Yust
Azaria Cohen, Vered Weisz, Noam Elbaum, Yaniv Halmut, Dan Mecrantz, Oren Bahat, and Udi
shtalrid
Dept. of Electrical Engineering-Systems
Tel Aviv University
Clinical Audiometric Tests
Audiograms
Speech Discrimination Tests
Otoacoustic Emissions
Audiometric Diagnosis
Conductive or Sensorineural Hearing Loss
Cochlear or Retrocochlear Hearing Loss
Inner Hair Cells or Outer Hair Cells Loss ?
The amount of Outer hair Cell Loss ?
Can a Cochlear model help in
Audiometric Diagnosis?
The Ear
Traveling Waves Tonotopic map of the Cochlea
Basilar Membrane Motion +Outer Hair Cells Amplification
Outer Hair Cell
Cochlear Model
helico trem a
ova lw indow
roundw indow
basila r m em brane
sca latym pan i
sca la vestibu li
x
baseapex
x
One dimensional model Based on fluid dynamics
Outer Hair Cell Model
Electromotile model OHC adds to basilar membrane pressure
Middle Ear Model
Oval window
Piston based model
Outer ear Middle ear
microphone
Incudostapedial joint
OWxinP T
M
Cochlear Representations of Tones
Cochlear representation
Cochlear Representation of Chirp
INPUT OUTPUT
Input Signal : Chirp 1-3 KHz
NormalCochlea
OHC Loss
Cochlear Representation of a click
Sta
pe
s
Apex
Stimulus
100us
Healthy Cochlea OHC Loss
Representation of a word
Input Signal: The word “SHEN”
INPUT OUTPUT
NormalCochlea
OHC Loss
Cochlear Representation of a Noisy Word
Input Signal: The word “SHEN” with Noise
INPUT OUTPUT
NormalCochlea
OHC Loss
Otoacoustic Emission
Introducing cochlear “roughness”
Model Prediction: Excitation Patterns
Normal Cochlea
No Active Outer Hair Cells
Damaged Cochlea
Estimated Audiograms
Normal OHC activity
Partial damaged OHC
No OHC activity
Estimated Audiograms
Simulated Audiograms
Partial OHC activity with “roughness”
Normal OHC activity with “roughness”
Damaged cochlear response
Partial OHC Loss
Measured Audiogram Model Prediction
Non Linear Properties
0 20 40 60 80 100 120 140-150
-100
-50
0Loudness.Stimuli Frequency=4000Hz
Stimuli Amplitude [dB]
Est
imat
ed L
oudn
ess
[dB
]Gamma=0.5
Gamma=0.3
Gamma=0.1
Gamma=0
Equal Loudness Countours
102
103
-20
0
20
40
60
80
100
120
140
Frequency (kHz)
Gamma=0.5
Ld=60Ld=55
Ld=50
Ld=45
Ld=40Ld=35
Ld=30
Ld=25Ld=20
Ld=15
Ld=10
Ld=5Ld=0
102
103
-20
0
20
40
60
80
100
120
140
Frequency (kHz)
Gamma=0.25
102
103
-20
0
20
40
60
80
100
120
140
Frequency (kHz)
Inpu
t S
timul
us L
evel
(dB
)
Gamma=0
Non Linear Respomseטון בודד – פילטרים
D=2.3cm CF=488Hz D=1.8cm CF=1074Hz
102
103
0
50
100
Gamma=0.5
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
102
103
0
50
100
Gamma=0.25
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
102
103
0
50
100
Gamma=0
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
40dB<Amp<100dB
120dB
140dB
40dB60dB80dB100dB120dB140dB
40dB60dB80dB100dB120dB140dB
102
103
0
50
100
Gamma=0.5
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
102
103
0
50
100
Gamma=0.25
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
102
103
0
50
100
Gamma=0
Frequency [Hz]
Vel
ocity
Gai
n [d
B]
60dB80dB100dB120dB140dB
60dB80dB100dB120dB140dB
60dB<Amp<100dB
120dB
140dB
Basilar Membrane Gain
Response to Two Tones:Combination Tones
Time Frequency
Input = 2kHz + 2.44kHz; Equal level
Healthy Cochlea
