scholarly journals Mathematical modeling of the radial profile of basilar membrane vibrations in the inner ear

2004 ◽  
Vol 116 (2) ◽  
pp. 1025-1034 ◽  
Author(s):  
Martin Homer ◽  
Alan Champneys ◽  
Giles Hunt ◽  
Nigel Cooper
Keyword(s):  
Mathematical Modeling ◽  
Inner Ear ◽  
Basilar Membrane ◽  
Radial Profile ◽  
Membrane Vibrations

Loud Sound-Induced Changes in Cochlear Mechanics

2002 ◽  
Vol 88 (5) ◽  
pp. 2341-2348 ◽  
Author(s):  
Anders Fridberger ◽  
Jiefu Zheng ◽  
Anand Parthasarathi ◽  
Tianying Ren ◽  
Alfred Nuttall
Keyword(s):  
Inner Ear ◽  
Time Course ◽  
Basilar Membrane ◽  
Organ Of Corti ◽  
Compound Action Potential ◽  
Cochlear Microphonic ◽  
Cochlear Function ◽  
Loud Sound ◽  
Induced Changes ◽  
Membrane Vibrations

To investigate the inner ear response to intense sound and the mechanisms behind temporary threshold shifts, anesthetized guinea pigs were exposed to tones at 100–112 dB SPL. Basilar membrane vibration was measured using laser velocimetry, and the cochlear microphonic potential, compound action potential of the auditory nerve, and local electric AC potentials in the organ of Corti were used as additional indicators of cochlear function. After exposure to a 12-kHz intense tone, basilar membrane vibrations in response to probe tones at the characteristic frequency of the recording location (17 kHz) were transiently reduced. This reduction recovered over the course of 50 ms in most cases. Organ of Corti AC potentials were also reduced and recovered with a time course similar to the basilar membrane. When using a probe tone at either 1 or 4 kHz, organ of Corti AC potentials were unaffected by loud sound, indicating that transducer channels remained intact. In most experiments, both the basilar membrane and the cochlear microphonic response to the 12-kHz overstimulation was constant throughout the duration of the intense stimulus, despite a large loss of cochlear sensitivity. It is concluded that the reduction of basilar membrane velocity that followed loud sound was caused by changes in cochlear amplification and that the cochlear response to intense stimulation is determined by the passive mechanical properties of the inner ear structures.

scholarly journals The Effect of Pulling Out Cochlear Implant Electrodes on Inner Ear Microstructures: A Temporal Bone Study

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Ingo Todt ◽  
Rainer O. Seidl ◽  
Arne Ernst
Keyword(s):  
Cochlear Implant ◽  
Inner Ear ◽  
Temporal Bone ◽  
Basilar Membrane ◽  
Temporal Sequence ◽  
Pull Out ◽  
Temporal Bones

The exchange of an cochlear implant or the re-positioning of an electrode have become more frequently required than a decade ago. The consequences of such procedures at a microstructural level within the cochlea are not known. It was the aim of the present study to further investigate the effects of an CI electrode pull-out. Therefore 10 freshly harvested temporal bones (TB) were histologically evaluated after a cochlear implant electrode pull-out of a perimodiolar electrode. In additional 9 TB the intrascalar movements of the CI electrode while being pulled-out were digitally analysed by video- capturing. Histologically, a disruption of the modiolar wall or the spiral osseous lamina were not observed. In one TB, a basilar membrane lifting up was found, but it could not be undoubtedly attributed to the pull-out of the electrode. When analyzing the temporal sequence of the electrode movement during the pull-out, the electrode turned in one case so that the tip elevates the basilar membrane. The pull- out of perimodiolarly placed CI electrodes does not damage the modiolar wall at a microstructural level and should be guided (e.g., forceps) to prevent a 90 o turning of the electrode tip into the direction of the basilar membrane.

scholarly journals The Biophysical Function of the Human Eardrum

2021 ◽  
Vol 3 (2) ◽  
pp. 103-107
Author(s):  
Janos Vincze ◽  
Gabriella Vincze-Tiszay
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Acoustic Signal ◽  
Basilar Membrane ◽  
Primary Auditory Cortex ◽  
Oval Window ◽  
Speech Comprehension ◽  
Sound Waves ◽  
Auditory Ossicles ◽  
Hearing System

The hearing analyzer consists of two main systems: the peripheral hearing system, formed of the outer ear, the middle ear and the inner ear and the central hearing system, which contains the nervous pathways which ensure the transmission of the nervous influx and the hearing area where the information is analyzed and the hearing sensation is generated. The peripheral hearing system achieves the functions of transmission of the sound vibration, the analysis of the acoustic signal and the transformation of the acoustic signal in nervous inflow and the generation of the nervous response. The human hearing is characteristics: 1. The eardrum vibrates from the sound waves; 2. Auditory ossicles amplify the stimulus; 3. In an oval window, the vibration is transmitted to the fluid space of the inner ear; 4. It vibrates the basilar membrane; 5. What is pressed against the membrane tectoria; 6. The stereocilliums of the hair cell bend, ion channels open; 7. Hair cell depolarizes; 8. Stimulus is dissipated in cerebrospinal fluid VIII (vestibulo¬cochlearis); 9. Temporal lobe primary auditory cortex (Brodman 41, 42); 10. Association pathways: speech comprehension (Wernicke area).

Extremely Small Motions of the Basilar Membrane in the Inner Ear

Nature ◽  
1970 ◽  
Vol 228 (5272) ◽  
pp. 678-679 ◽  
Author(s):  
P. ALLAIRE ◽  
M. BILLONE ◽  
S. RAYNOR
Keyword(s):  
Inner Ear ◽  
Basilar Membrane

scholarly journals Toward steerable electrodes. An overview of concepts and current research.

2017 ◽  
Vol 3 (2) ◽  
pp. 765-769 ◽  
Author(s):  
Thomas S. Rau ◽  
Silke Hügl ◽  
Thomas Lenarz ◽  
Omid Majdani
Keyword(s):  
Inner Ear ◽  
Cochlear Implants ◽  
Basilar Membrane ◽  
Clinical Success ◽  
Electrode Array ◽  
Surrounding Tissue ◽  
Clinical Implementation ◽  
The Past ◽  
The Individual ◽  
Insertion Process

AbstractRestoration of hearing is a demanding surgical task which requires the insertion of a cochlear implant electrode array into the inner ear while preserving the delicate basilar membrane inside the cochlea for an atraumatic insertion. Already shortly after the first clinical success with early versions of cochlear implants the desire for a controlled insertion of the electrode array arose. Such a steerable electrode should be in its shape adaptable to the individual path of the helical inner ear in order to avoid any contact between the implant and the surrounding tissue. This article provides a short overview of concepts and actuator mechanisms investigated in the past and present with the objective of developing a steerable electrode array for an individualized insertion process. Although none of these concepts has reached clinical implementation, there are promising experimental results indicating that insertion forces can be reduced up to 60% compared to straight and not steerable electrodes. Finally, related research topics are listed which require considerable further improvements until steerable electrodes will reach clinical applicability.

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