Jozef Zwislocki in the post‐von Bekesy era of cochlear physiology

2003 ◽  
Vol 113 (4) ◽  
pp. 2248-2248
Author(s):  
William S. Rhode
Keyword(s):  
1981 ◽  
Vol 32 (1) ◽  
pp. 153-190 ◽  
Author(s):  
P Dallos
Keyword(s):  

2015 ◽  
Vol 58 (2) ◽  
pp. 123-135
Author(s):  
Takashi Nakagawa

1980 ◽  
Vol 86 (1) ◽  
pp. 153-170
Author(s):  
R. B. COLES ◽  
D. B. LEWIS ◽  
K. G. HILL ◽  
M. E. HUTCHINGS ◽  
D. M. GOWER

The directional sensitivity of cochlear microphonics (CM) was studied inthe quail by rotating a free-field sound source (pure tones, 160-10 kHz)through 360° in the horizontal plane, under anechoic conditions. Sound diffraction by the head was monitored simultaneously by a microphone at the entrance to the ipsilateral (recorded) ear canal. Pressure-field fluctuations measured by the microphone were non-directional (≤ 4 dB) up to 4 kHz; the maximum head shadow was 8 dB at 6.3 kHz. In comparison, the CM sensitivity under went directional fluctuations ranging up to 25 dB for certain low, mid and high frequency band widths. There was noticeable variation between quail for frequencies producing maximum directional effects, although consistently poor directionality was seen near 820 Hz andto a lesser extent near 3.5 kHz. Well-defined CM directivity patterns reflected the presence of nulls (insensitive regions) at critical positions around the head and the number of nulls increased with frequency. Five major types of directivity patterns were defined using polar co-ordinates: cardioid, supercardioid, figure-of-eight, tripartite and multilobed. Such patterns were largely unrelated to head shadow effects. Blocking the ear canal contralateral to there corded ear was shown to effectively abolish CM directionality, largely by eliminating regions of insensitivity to sound. It is inferred that the quail ear functions as an asym metrical pressure gradient receiver, the pressure gradient function being mediated by the interauralcavity. It is proposed that the central auditory system codes directional information by a null detecting method and computes an unambiguous (i.e.intensity independent) directional cue. This spatial cue is achieved by the difference between the directional sensitivities of the two ears, defined as the Directional Index (DI). The spatial distribution of DI values (difference pattern) demonstrated ranges and peaks which closely reflected the extent and position of nulls determined from monaural directivity functions. Large directional cues (up to 25 dB) extended throughout most of the audible spectrum of the quail and the sharpness of difference patterns increased with frequency. Primary ‘best’ directions, estimated from peaks in difference patterns, tended to move towards the front of the head at higher frequencies; rearward secondary peaks also occurred. From the properties of directional cues it is suggested that the ability of birds to localize sound need not necessarily depend on frequency; however, spatial acuity may be both frequency and direction dependent, and include the possibility of front-torearerrors. The directional properties of bird vocalizations may need to bere assessed on the basis of the proposed mechanism for directional hearing.


Author(s):  
R. Szalai ◽  
K. Tsaneva-Atanasova ◽  
M. E. Homer ◽  
A. R. Champneys ◽  
H. J. Kennedy ◽  
...  

This paper reviews current understanding and presents new results on some of the nonlinear processes that underlie the function of the mammalian cochlea. These processes occur within mechano-sensory hair cells that form part of the organ of Corti. After a general overview of cochlear physiology, mathematical modelling results are presented in three parts. First, the dynamic interplay between ion channels within the sensory inner hair cells is used to explain some new electrophysiological recordings from early development. Next, the state of the art is reviewed in modelling the electro-motility present within the outer hair cells (OHCs), including the current debate concerning the role of cell body motility versus active hair bundle dynamics. A simplified model is introduced that combines both effects in order to explain observed amplification and compression in experiments. Finally, new modelling evidence is presented that structural longitudinal coupling between OHCs may be necessary in order to capture all features of the observed mechanical responses.


1998 ◽  
Vol 118 (1-2) ◽  
pp. 168-176 ◽  
Author(s):  
James D Fessenden ◽  
Jochen Schacht

1999 ◽  
Vol 518 (3) ◽  
pp. 667-680 ◽  
Author(s):  
J. Ruel ◽  
C. Chen ◽  
R. Pujol ◽  
R. P. Bobbin ◽  
J. L. Puel

2012 ◽  
Vol 293 (1-2) ◽  
pp. 12-20 ◽  
Author(s):  
John J. Guinan ◽  
Alec Salt ◽  
Mary Ann Cheatham
Keyword(s):  

1981 ◽  
Vol 4 ◽  
pp. 106-109
Author(s):  
J.R. Johnstone
Keyword(s):  

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