Histological evaluation of damage in cat cochleas used for measurement of basilar membrane mechanics

1984 ◽  
Vol 75 (2) ◽  
pp. 515-527 ◽  
Author(s):  
D. G. B. Leonard ◽  
S. M. Khanna
Keyword(s):  
Basilar Membrane ◽  
Histological Evaluation ◽  
Membrane Mechanics

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.

Clarion 1.2® standard electrode array with partial space-filling positioner: radiological and histological evaluation in human temporal bones

2002 ◽  
Vol 116 (7) ◽  
pp. 507-513 ◽  
Author(s):  
Bernhard Richter ◽  
Antje Aschendorff ◽  
Petra Lohnstein ◽  
Hartmut Husstedt ◽  
Heiner Nagursky ◽  
...  
Keyword(s):  
Major Trauma ◽  
Histological Analysis ◽  
Basilar Membrane ◽  
Electrode Array ◽  
Histological Evaluation ◽  
Cross Sectional ◽  
Close Proximity ◽  
Safety Studies ◽  
Cross Sectional Imaging ◽  
Temporal Bones

The purpose of this study was to evaluate whether use of a positioner for situating the Clarion 1.2® standard electrode array in close proximity to the modiolus, causes damage to fine intra-cochlear structures, and to provide a comparison with results obtained for insertions of the array performed without a positioner. The study was performed in seven freshly frozen human temporal bones. Electrode location and intra-cochlear trauma was analysed using cross-sectional imaging and histological analysis. Insertion of the Clarion® array did not reveal major trauma. The devices inserted with the positioner showed a consistently closer location of the electron array towards the modiolus, however, insertion resulted in significant displacement of both the electrode array and the positioner resulting in severe destruction of the basilar membrane and osseous spiral lamina along the length of the basal and middle turns. The devices inserted with the positioner resulted in major trauma to the basilar membrane and osseous spiral lamina. Therefore, systematic safety studies in larger samples of human temporal bones should be performed and the results carefully evaluated before implantation can be recommended unreservedly.

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