Design and Simulation of Geometrical Shape and Size Variations of Micro-electrode for Cochlear Implant

2020 ◽  
pp. 69-75
Author(s):  
Abhishek Nigam ◽  
Faiz Ahmed ◽  
S. J. Pawar
Keyword(s):  
Cochlear Implant ◽  
Geometrical Shape ◽  
Shape And Size

scholarly journals Shape- and size-dependent electronic capacitance in nanostructured materials

2013 ◽  
Vol 469 (2158) ◽  
pp. 20130163 ◽  
Author(s):  
Maibam Birla Singh ◽  
Rama Kant
Keyword(s):  
Scattering Method ◽  
Geometrical Shape ◽  
Nano Materials ◽  
Screening Length ◽  
Size Dependent ◽  
Electronic Screening ◽  
Spillover Correction ◽  
Geometrical Factors ◽  
Multiple Scattering Method ◽  
Shape And Size

The shape and size are the two important geometrical factors that affect the electronic screening in nano-materials. Here, we develop an analytical theory for electronic capacitance based on Thomas–Fermi screening in conjunction with ‘multiple scattering method’ for arbitrary-shaped nanostructures including electronic spillover correction. We relate the electronic capacitance of the material to the curvature correction expressed in terms of ratio of electronic screening length to principal radii of curvature. Electronic capacitance of various nanostructures is obtained showing geometrical shape- and size-dependent electronic screening in nanostructures that manifest important consequences in charge storage enhancement or reduction.

Positioning of the receiver-stimulator for the CI–24M cochlear implant in infants

1999 ◽  
Vol 113 (3) ◽  
pp. 212-216 ◽  
Author(s):  
T. E. Mitchell ◽  
W. P. R. Gibson
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Skull Growth ◽  
One Year ◽  
Shape And Size

AbstractA new cochlear implant (CI–24M) has recently been released by Cochlear Ltd. The shape and size of the receiver-stimulator differs from that of the CI–22M. Infants as young as one year of age are now receiving cochlear implants. We have examined the likely effect of skull growth following the implantation of a CI-24M cochlear implant in an infant of this age.

The Effect of the Geometrical Shape and Size of the Cross Section on the Spin-Polarized Transport and the Giant Magnetoresistance : Finite Element Method Analysis

2007 ◽  
Vol 124-126 ◽  
pp. 843-846
Author(s):  
Eun Sun Noh ◽  
Sergio E. Ulloa ◽  
Hyuck Mo Lee
Keyword(s):  
Cross Section ◽  
Giant Magnetoresistance ◽  
Geometrical Shape ◽  
Transmission Coefficients ◽  
Spin Polarized ◽  
Polarized Transport ◽  
The Cross ◽  
Spin Polarized Transport ◽  
Shaped Cross Section ◽  
Shape And Size

We analyze the effect of the geometrical shape and size of the cross section on the spin-polarized transport and the giant magnetoresistance (GMR) by a finite element method, and evaluate the stability and the physical properties of nano-scale spin valves. We calculate the transmission coefficients in the ballistic regime by using a transfer-matrix method, and evaluate the GMR of the current perpendicular to the plane (CPP) by using a circuit theory. The conduction-band structure is simplified to the potential step, which is determined by combining the interfacial parameters calculated by first-principles with the free electron model. The geometrical shapes of the cross section are line and square. As a result, the cross sectional shape has a significant effect on the spin-polarized transport and the GMR. The square-shaped cross section has an advantage of the large GMR, which is contrary to the line-shaped cross section. These phenomena result from the difference of the cut-off energies with the transverse modes and, consequently, the different spin-down transmission coefficients.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

Letter to the Editor Concerning Skuk et al., “Parameter-Specific Morphing Reveals Contributions of Timbre and Fundamental Frequency Cues to the Perception of Voice Gender and Age in Cochlear Implant Users”

2020 ◽  
Vol 63 (12) ◽  
pp. 4325-4326 ◽  
Author(s):  
Hartmut Meister ◽  
Katrin Fuersen ◽  
Barbara Streicher ◽  
Ruth Lang-Roth ◽  
Martin Walger
Keyword(s):  
Cochlear Implant ◽  
Fundamental Frequency ◽  
Stimulus Type ◽  
Voice Perception ◽  
Letter To The Editor ◽  
Gender And Age ◽  
General Influence

Purpose The purpose of this letter is to compare results by Skuk et al. (2020) with Meister et al. (2016) and to point to a potential general influence of stimulus type. Conclusion Our conclusion is that presenting sentences may give cochlear implant recipients the opportunity to use timbre cues for voice perception. This might not be the case when presenting brief and sparse stimuli such as consonant–vowel–consonant or single words, which were applied in the majority of studies.

Perceptual Learning of Vocoded Speech With and Without Contralateral Hearing: Implications for Cochlear Implant Rehabilitation

2020 ◽  
pp. 1-10
Author(s):  
Martin Chavant ◽  
Alexis Hervais-Adelman ◽  
Olivier Macherey
Keyword(s):  
Cochlear Implant ◽  
Perceptual Learning ◽  
Speech Signal ◽  
Training Phase ◽  
Monosyllabic Words ◽  
Low Pass ◽  
Contralateral Ear ◽  
Number Of Individuals ◽  
Insight Into ◽  
Vocoded Speech

Purpose An increasing number of individuals with residual or even normal contralateral hearing are being considered for cochlear implantation. It remains unknown whether the presence of contralateral hearing is beneficial or detrimental to their perceptual learning of cochlear implant (CI)–processed speech. The aim of this experiment was to provide a first insight into this question using acoustic simulations of CI processing. Method Sixty normal-hearing listeners took part in an auditory perceptual learning experiment. Each subject was randomly assigned to one of three groups of 20 referred to as NORMAL, LOWPASS, and NOTHING. The experiment consisted of two test phases separated by a training phase. In the test phases, all subjects were tested on recognition of monosyllabic words passed through a six-channel “PSHC” vocoder presented to a single ear. In the training phase, which consisted of listening to a 25-min audio book, all subjects were also presented with the same vocoded speech in one ear but the signal they received in their other ear differed across groups. The NORMAL group was presented with the unprocessed speech signal, the LOWPASS group with a low-pass filtered version of the speech signal, and the NOTHING group with no sound at all. Results The improvement in speech scores following training was significantly smaller for the NORMAL than for the LOWPASS and NOTHING groups. Conclusions This study suggests that the presentation of normal speech in the contralateral ear reduces or slows down perceptual learning of vocoded speech but that an unintelligible low-pass filtered contralateral signal does not have this effect. Potential implications for the rehabilitation of CI patients with partial or full contralateral hearing are discussed.

Sign in / Sign up

Export Citation Format

Share Document