Basilar membrane mechanics at the base of the chinchilla cochlea. I. Input–output functions, tuning curves, and response phases

1986 ◽  
Vol 80 (5) ◽  
pp. 1364-1374 ◽  
Author(s):  
Luis Robles ◽  
Mario A. Ruggero ◽  
Nola C. Rich
Keyword(s):  
Basilar Membrane ◽  
Membrane Mechanics ◽  
Input Output ◽  
Tuning Curves

Modeling DPOAE Input/Output Function Compression: Comparisons with Hearing Thresholds

2014 ◽  
Vol 25 (08) ◽  
pp. 746-759 ◽  
Author(s):  
Shaum P. Bhagat
Keyword(s):  
Research Design ◽  
Basilar Membrane ◽  
Otoacoustic Emission ◽  
Normal Hearing ◽  
Membrane Mechanics ◽  
Distortion Product Otoacoustic Emission ◽  
Input Output ◽  
Distortion Product ◽  
Hearing Thresholds ◽  
Cochlear Compression

Background: Basilar membrane input/output (I/O) functions in mammalian animal models are characterized by linear and compressed segments when measured near the location corresponding to the characteristic frequency. A method of studying basilar membrane compression indirectly in humans involves measuring distortion-product otoacoustic emission (DPOAE) I/O functions. Previous research has linked compression estimates from behavioral growth-of-masking functions to hearing thresholds. Purpose: The aim of this study was to compare compression estimates from DPOAE I/O functions and hearing thresholds at 1 and 2 kHz. Research Design: A prospective correlational research design was performed. The relationship between DPOAE I/O function compression estimates and hearing thresholds was evaluated with Pearson product-moment correlations. Study Sample: Normal-hearing adults (n = 16) aged 22–42 yr were recruited. Data Collection and Analysis: DPOAE I/O functions (L 2 = 45–70 dB SPL) and two-interval forced-choice hearing thresholds were measured in normal-hearing adults. A three-segment linear regression model applied to DPOAE I/O functions supplied estimates of compression thresholds, defined as breakpoints between linear and compressed segments and the slopes of the compressed segments. Pearson product-moment correlations between DPOAE compression estimates and hearing thresholds were evaluated. Results: A high correlation between DPOAE compression thresholds and hearing thresholds was observed at 2 kHz, but not at 1 kHz. Compression slopes also correlated highly with hearing thresholds only at 2 kHz. Conclusions: The derivation of cochlear compression estimates from DPOAE I/O functions provides a means to characterize basilar membrane mechanics in humans and elucidates the role of compression in tone detection in the 1–2 kHz frequency range.

scholarly journals Investigating time-efficiency of forward masking paradigms for estimating basilar membrane input-output characteristics

PLoS ONE ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. e0174776 ◽  
Author(s):  
Michal Fereczkowski ◽  
Morten L. Jepsen ◽  
Torsten Dau ◽  
Ewen N. MacDonald
Keyword(s):  
Basilar Membrane ◽  
Forward Masking ◽  
Input Output ◽  
Time Efficiency ◽  
Output Characteristics

scholarly journals Vibration of the organ of Corti within the cochlear apex in mice

2014 ◽  
Vol 112 (5) ◽  
pp. 1192-1204 ◽  
Author(s):  
Simon S. Gao ◽  
Rosalie Wang ◽  
Patrick D. Raphael ◽  
Yalda Moayedi ◽  
Andrew K. Groves ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Difference ◽  
Basilar Membrane ◽  
Organ Of Corti ◽  
Lateral Compartment ◽  
Outer Hair Cells ◽  
Supporting Cells ◽  
Tuning Curves ◽  
Cochlear Amplification

The tonotopic map of the mammalian cochlea is commonly thought to be determined by the passive mechanical properties of the basilar membrane. The other tissues and cells that make up the organ of Corti also have passive mechanical properties; however, their roles are less well understood. In addition, active forces produced by outer hair cells (OHCs) enhance the vibration of the basilar membrane, termed cochlear amplification. Here, we studied how these biomechanical components interact using optical coherence tomography, which permits vibratory measurements within tissue. We measured not only classical basilar membrane tuning curves, but also vibratory responses from the rest of the organ of Corti within the mouse cochlear apex in vivo. As expected, basilar membrane tuning was sharp in live mice and broad in dead mice. Interestingly, the vibratory response of the region lateral to the OHCs, the “lateral compartment,” demonstrated frequency-dependent phase differences relative to the basilar membrane. This was sharply tuned in both live and dead mice. We then measured basilar membrane and lateral compartment vibration in transgenic mice with targeted alterations in cochlear mechanics. Prestin499/499, Prestin−/−, and TectaC1509G/C1509G mice demonstrated no cochlear amplification but maintained the lateral compartment phase difference. In contrast, SfswapTg/Tg mice maintained cochlear amplification but did not demonstrate the lateral compartment phase difference. These data indicate that the organ of Corti has complex micromechanical vibratory characteristics, with passive, yet sharply tuned, vibratory characteristics associated with the supporting cells. These characteristics may tune OHC force generation to produce the sharp frequency selectivity of mammalian hearing.

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