Transcript es2005 5400

Shyamla Narayan
Ed Overstreet
Burt Evans
Alberto Recio
Andrei Temchin
Laboratory for Hearing Biology (~1996)
Laboratory for
Hearing Biology (today)
Luis Robles
Jon Siegel
Andrei Temchin
Yun-Hui Fan
Qin Gong
Yi-Bo Fan
AT THE BASE OF THE COCHLEA, BASILARMEMBRANE RESPONSES TO CHARACTERISTICFREQUENCY TONES GROW AT HIGHLY
COMPRESSIVE RATES (e.g., 0.2 dB/dB)
BM Displacement (nm)
100.00
chinchilla
10.00
1.00
guinea pig
0.10
cat
0.01
0
10
20
30
40
50
60
70
Sound Pressure Level (dB)
80
90
100
110
COMPRESSIVE NONLINEARITY IN
BASILAR-MEMBRANE RESPONSES
TO CLICKS
104 dB SPL
84
Sensitivity (mm/s/Pa)
25
15
5
64
-5
-15
L113
-25
0
1
2
Time (ms)
3
4
5
IN SPITE OF THE PROMINENT
NONLINEARITIES OF BASILAR-MEMBRANE
VIBRATIONS, THE FOURIER SPECTRA OF
RESPONSES TO CLICKS MATCH, LEVEL
BY LEVEL, THE RESPONSES TO TONES
Gain (mm/s/Pa)
1000
100
20 dB SPL
30
40
50
60
70
80
90
24
34
10
1
L113
0.1
104
GROWTH OF PEAKS IN RESPONSES TO
CLICKS AS A FUNCTION OF STIMULUS
LEVEL
10000
L13
7
5
3
2
0.2 dB/dB
Velocity (m/s)
1000
100
L110
0.2 dB/dB
7
5
3
2
P7
P7
P17
1 dB/dB
P3
P1
7
5
3
2
P1
P17
1 dB/dB
P3
10
10000
L113
L125
0.2 dB/dB
0.2 dB/dB
1000
P3
P7
P7
100
P1
P3
P17
10
20
40
1 dB/dB
P1
60
80
100
30
50
Level (dB SPL)
Fig. 7 Jan. 28, 2005 2:10:42 PM
P17
1 dB/dB
70
90
110
COMPRESSIVE NONLINEARITY IS
PRESENT WITHIN A SINGLE PERIOD
OF RESPONSE OSCILLATION
Mean slope (dB/dB)
1.0
L13
L110
L113
L125
0.8
0.6
0.4
0.2
0
0
0.5
1.0
1.5
Time (ms)
Fig.8 Jan. 28, 2005 2:17:15 PM
2.0
2.5
3.0
IN THE CHINCHILLA, BASILAR-MEMBRANE
RESPONSES ARE MORE SHARPLY TUNED
AND EXHIBIT GREATER NONLINEARITY
AT THE BASE OF THE COCHLEA THAN AT
THE APEX
10000
CF=9 kHz
Sensitivity (mm/s/Pa)
1000
CF=0.5 kHz
48 dB
56 dB
100
15 dB
10
1
0.1
0.01
BFhigh SPL=0.5 kHz
Q10= 0.9
0.5
1
1.5
2
BFhigh SPL=7 kHz
Q10= 1.6
0.5
Frequency normalized to CF
1
1.5
2
Compression and other nonlinearities of BM
responses probably arise in nonlinear transduction
in outer hair cells
Cooper, 2003
RESPONSES OF AUDITORY-NERVE FIBERS
EXHIBIT AN INTENSITY-DEPENDENT PHASE
SHIFT THAT IS NOT PRESENT IN BASILARMEMBRANE RESPONSES
SECOND-ORDER WIENER KERNELS OF
AUDITORY-NERVE FIBERS RESPONSES
TO NOISE
FRONT, GROUP AND FILTER DELAYS
MAP OF DELAYS FOR
THE CHINCHILLA COCHLEA
COMPARISON OF GROUP DELAYS OF
BASILAR-MEMBRANE VIBRATIONS AND
STIMULUS-FREQUENCY OTOACOUSTIC
EMISSIONS (SFOAEs)
BASILA-MEMBRANE RESPONSES AT
THE BASE OF THE COCHLEA ARE NOT
MINIMUM-PHASE
Original response
(time domain)
44 dB SPL
104 dB SPL
Minimum-phase version
BASAL RESPONSES ARE NOT MINIMUM-PHASE
44 dB SPL
(frequency domain)
104 dB SPL
THE MEASURED PHASE SHIFTS AS A FUNCTION
OF GAIN ARE MUCH SMALLER THAN
EXPECTED FROM MINIMUM-PHASE BEHAVIOR
EVEN POST-MORTEM RESPONSES
ARE NOT MINIMUM-PHASE
BASILAR-MEMBRANE RESPONSES AT THE
APEX OF THE COCHLEA ARE NOT MINIMUM-PHASE
DEVELOPMENT OF BASILAR-MEMBRANE
VIBRATIONS IN NEW-BORN GERBILS:
RUDIMENTARY TRAVELING WAVE
POST-MORTEM BASILAR-MEMBRANE
RESPONSES IN ADULT GERBIL ARE NOT
MINIMUM-PHASE
BUT IN-VIVO BASILAR-MEMBRANE RESPONSES
IN IMMATURE COCHLEAE ARE MINIMUM-PHASE