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Adenis V, Partouche E, Stahl P, Gnansia D, Huetz C, Edeline JM. Asymmetric pulses delivered by a cochlear implant allow a reduction in evoked firing rate and in spatial activation in the guinea pig auditory cortex. Hear Res 2024; 447:109027. [PMID: 38723386 DOI: 10.1016/j.heares.2024.109027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Despite that fact that the cochlear implant (CI) is one of the most successful neuro-prosthetic devices which allows hearing restoration, several aspects still need to be improved. Interactions between stimulating electrodes through current spread occurring within the cochlea drastically limit the number of discriminable frequency channels and thus can ultimately result in poor speech perception. One potential solution relies on the use of new pulse shapes, such as asymmetric pulses, which can potentially reduce the current spread within the cochlea. The present study characterized the impact of changing electrical pulse shapes from the standard biphasic symmetric to the asymmetrical shape by quantifying the evoked firing rate and the spatial activation in the guinea pig primary auditory cortex (A1). At a fixed charge, the firing rate and the spatial activation in A1 decreased by 15 to 25 % when asymmetric pulses were used to activate the auditory nerve fibers, suggesting a potential reduction of the spread of excitation inside the cochlea. A strong "polarity-order" effect was found as the reduction was more pronounced when the first phase of the pulse was cathodic with high amplitude. These results suggest that the use of asymmetrical pulse shapes in clinical settings can potentially reduce the channel interactions in CI users.
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Affiliation(s)
- V Adenis
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), France; CNRS UMR 9197, 91405 Orsay cedex, France; Université Paris-Saclay, 91405 Orsay cedex, France
| | - E Partouche
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), France; CNRS UMR 9197, 91405 Orsay cedex, France; Université Paris-Saclay, 91405 Orsay cedex, France
| | - P Stahl
- Oticon Medical, Vallauris, France
| | | | - C Huetz
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), France; CNRS UMR 9197, 91405 Orsay cedex, France; Université Paris-Saclay, 91405 Orsay cedex, France
| | - J-M Edeline
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), France; CNRS UMR 9197, 91405 Orsay cedex, France; Université Paris-Saclay, 91405 Orsay cedex, France.
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Stahl P, Dang K, Vandersteen C, Guevara N, Clerc M, Gnansia D. Current distribution of distributed all-polar cochlear implant stimulation mode measured in-situ. PLoS One 2022; 17:e0275961. [PMID: 36315506 PMCID: PMC9621453 DOI: 10.1371/journal.pone.0275961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
Oticon Medical cochlear implants use a stimulation mode called Distributed All-Polar (DAP) that connects all non-stimulating available intracochlear electrodes and an extracochlear reference electrode. It results in a complex distribution of current that is yet undescribed. The present study aims at providing a first characterization of this current distribution. A Neuro Zti was modified to allow the measurement of current returning to each electrode during a DAP stimulation and was implanted in an ex-vivo human head. Maps of distributed current were then created for different stimulation conditions with different charge levels. Results show that, on average, about 20% of current returns to the extracochlear reference electrode, while the remaining 80% is distributed between intracochlear electrodes. The position of the stimulating electrode changed this ratio, and about 10% more current to the extracochlear return in case of the first 3 basal electrodes than for apical and mid position electrodes was observed. Increasing the charge level led to small but significant change in the ratio, and about 4% more current to the extracochlear return was measured when increasing the charge level from 11.7 to 70 nC. Further research is needed to show if DAP yields better speech understanding than other stimulation modes.
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Affiliation(s)
- Pierre Stahl
- Department of Research and Technology, Oticon Medical, Vallauris, France
- * E-mail:
| | - Kai Dang
- Department of Research and Technology, Oticon Medical, Vallauris, France
- Athena Project Team, INRIA, Université Côte d’Azur, Nice, France
| | - Clair Vandersteen
- Head and Neck Surgery Institute, Nice University Hospital, Nice Cedex, France
| | - Nicolas Guevara
- Head and Neck Surgery Institute, Nice University Hospital, Nice Cedex, France
| | - Maureen Clerc
- Athena Project Team, INRIA, Université Côte d’Azur, Nice, France
| | - Dan Gnansia
- Department of Research and Technology, Oticon Medical, Vallauris, France
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Partouche E, Adenis V, Gnansia D, Stahl P, Edeline JM. Increased Threshold and Reduced Firing Rate of Auditory Cortex Neurons after Cochlear Implant Insertion. Brain Sci 2022; 12:brainsci12020205. [PMID: 35203968 PMCID: PMC8870646 DOI: 10.3390/brainsci12020205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 12/10/2022] Open
Abstract
The cochlear implant (CI) is the most successful neuroprosthesis allowing thousands of patients with profound hearing loss to recover speech understanding. Recently, cochlear implants have been proposed to subjects with residual hearing and, in these cases, shorter CIs were implanted. To be successful, it is crucial to preserve the patient’s remaining hearing abilities after the implantation. Here, we quantified the effects of CI insertion on the responses of auditory cortex neurons in anesthetized guinea pigs. The responses of auditory cortex neurons were determined before and after the insertion of a 300 µm diameter CI (six stimulating electrodes, length 6 mm). Immediately after CI insertion there was a 5 to 15 dB increase in the threshold for cortical neurons from the middle to the high frequencies, accompanied by a decrease in the evoked firing rate. Analyzing the characteristic frequency (CF) values revealed that in large number of cases, the CFs obtained after insertion were lower than before. These effects were not detected in the control animals. These results indicate that there is a small but immediate cortical hearing loss after CI insertion, even with short length CIs. Therefore, efforts should be made to minimize the damages during CI insertion to preserve the cortical responses to acoustic stimuli.
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Affiliation(s)
- Elie Partouche
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Universite Paris-Saclay, 91400 Saclay, France; (E.P.); (V.A.)
| | - Victor Adenis
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Universite Paris-Saclay, 91400 Saclay, France; (E.P.); (V.A.)
| | - Dan Gnansia
- Department of Scientific and Clinical Research, Oticon Medical, 06224 Vallauris, France; (D.G.); (P.S.)
| | - Pierre Stahl
- Department of Scientific and Clinical Research, Oticon Medical, 06224 Vallauris, France; (D.G.); (P.S.)
| | - Jean-Marc Edeline
- Paris-Saclay Institute of Neurosciences (Neuro-PSI), CNRS UMR 9197, Universite Paris-Saclay, 91400 Saclay, France; (E.P.); (V.A.)
- Correspondence:
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Wang Z, Demarcy T, Vandersteen C, Gnansia D, Raffaelli C, Guevara N, Delingette H. Bayesian logistic shape model inference: Application to cochlear image segmentation. Med Image Anal 2021; 75:102268. [PMID: 34710654 DOI: 10.1016/j.media.2021.102268] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/01/2021] [Accepted: 10/08/2021] [Indexed: 11/28/2022]
Abstract
Incorporating shape information is essential for the delineation of many organs and anatomical structures in medical images. While previous work has mainly focused on parametric spatial transformations applied to reference template shapes, in this paper, we address the Bayesian inference of parametric shape models for segmenting medical images with the objective of providing interpretable results. The proposed framework defines a likelihood appearance probability and a prior label probability based on a generic shape function through a logistic function. A reference length parameter defined in the sigmoid controls the trade-off between shape and appearance information. The inference of shape parameters is performed within an Expectation-Maximisation approach in which a Gauss-Newton optimization stage provides an approximation of the posterior probability of the shape parameters. This framework is applied to the segmentation of cochlear structures from clinical CT images constrained by a 10-parameter shape model. It is evaluated on three different datasets, one of which includes more than 200 patient images. The results show performances comparable to supervised methods and better than previously proposed unsupervised ones. It also enables an analysis of parameter distributions and the quantification of segmentation uncertainty, including the effect of the shape model.
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Affiliation(s)
- Zihao Wang
- Inria, Epione Team, Université Côte d'Azur, Sophia Antipolis, France.
| | - Thomas Demarcy
- Oticon Medical, 14 Chemin de Saint-Bernard Porte, Vallauris 06220, France
| | - Clair Vandersteen
- Inria, Epione Team, Université Côte d'Azur, Sophia Antipolis, France; Head and Neck University Institute, Nice University Hospital, 31 Avenue de Valombrose, Nice 06100, France
| | - Dan Gnansia
- Oticon Medical, 14 Chemin de Saint-Bernard Porte, Vallauris 06220, France
| | - Charles Raffaelli
- Department of Radiology, Centre Hospitalier Universitaire de Nice, 31 Avenue de Valombrose, Nice 06100, France
| | - Nicolas Guevara
- Head and Neck University Institute, Nice University Hospital, 31 Avenue de Valombrose, Nice 06100, France
| | - Hervé Delingette
- Inria, Epione Team, Université Côte d'Azur, Sophia Antipolis, France
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Danieli F, Reis ACMB, Massuda ET, Amaral MSAD, Hoen M, Gnansia D, Hyppolito MÂ. Clinical implications of intraoperative eABRs to the Evo®-CI electrode array recipients. Braz J Otorhinolaryngol 2021; 88 Suppl 1:S108-S117. [PMID: 34034979 PMCID: PMC9734272 DOI: 10.1016/j.bjorl.2021.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/30/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION Electrically evoked auditory brainstem responses provide reliable clinical information to assist professionals in the auditory rehabilitation of cochlear implant users. OBJECTIVE This study aimed to investigate intraoperative evoked auditory brainstem response recordings in Evo®-cochlear implant electrode array recipients and its correlation with their behavioral levels and auditory performance. METHODS This is a retrospectivey study. Intraoperative evoked auditory brainstem responses were recorded in adult Evo®-cochlear implant electrode array recipients. Wave V latencies, amplitudes and interpeak III-V intervals were recorded in three different electrode locations and compared to the sentence recognition scores obtained from subjects after six months of device use. Evoked auditory brainstem responses thresholds were also recorded and compared to the behaviorally determined levels of the subjects in the sound processor activation. RESULTS Evoked auditory brainstem responses thresholds were significantly correlated with both, behavioral T- and C-levels and they were recorded at audible electrical stimulation levels in all subjects. There was a significant correlation between interpeak III-V interval recorded in the apical electrode and sentence recognition scores of the subjects. CONCLUSIONS Intraoperative evoked auditory brainstem responses can be used to establish audible levels for fitting the sound processor in Evo®-cochlear implant recipients and it could help professionals to plan further actions aiming to improve their auditory performance.
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Affiliation(s)
- Fabiana Danieli
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Programa de Pós-Graduação do Departamento de Oftalmologia, Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Ribeirão Preto, SP, Brazil; Oticon Medical, Departamento Clínico, São Paulo, SP, Brazil.
| | | | - Eduardo Tanaka Massuda
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Oftalmologia, Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Ribeirão Preto, SP, Brazil
| | - Maria Stella Arantes do Amaral
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Oftalmologia, Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Ribeirão Preto, SP, Brazil
| | - Michel Hoen
- Oticon Medical, Department of Scientific and Clinical Research, Vallauris, France
| | - Dan Gnansia
- Oticon Medical, Department of Scientific and Clinical Research, Vallauris, France
| | - Miguel Ângelo Hyppolito
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Oftalmologia, Otorrinolaringologia, Cirurgia de Cabeça e Pescoço, Ribeirão Preto, SP, Brazil
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Schramm D, Chen J, Morris DP, Shoman N, Philippon D, Cayé-Thomasen P, Hoen M, Karoui C, Laplante-Lévesque A, Gnansia D. Clinical efficiency and safety of the oticon medical neuro cochlear implant system: a multicenter prospective longitudinal study. Expert Rev Med Devices 2020; 17:959-967. [PMID: 32885711 DOI: 10.1080/17434440.2020.1814741] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE This prospective longitudinal cohort study at six tertiary referral centers in Canada and Denmark describes the clinical efficiency and surgical safety of cochlear implantation with the Oticon Medical Neuro cochlear implant system, including the Neuro Zti implant, the EVO electrode array, and the Neuro One sound processor. METHODS Patients were adult cochlear implant candidates with bilateral sensorineural hearing loss. RESULTS The mean HINT scores in quiet pre-operatively and at 3, 6, and 12 months post-activation were 13%, 58%, 67%, and 72%, respectively, and in noise (+10 dB SNR) 13%, 46%, 53%, and 59%, respectively. The mean improvement from baseline to 6 months post-activation was 54% in quiet and 40% in noise. The surgical major complication incidence rate was 0% and the post-surgical major complication incidence rate (until 12 months post-activation) was 4%. There was no adverse event that was fatal, that required explantation, or that resulted in sound processor nonuse, and no implant failure. CONCLUSION Cochlear implantation with the Oticon Medical Neuro system enables speech identification both in quiet and in noise and audiologic outcomes continue to improve in the year following activation. No substantial adverse events occurred during the surgical implantation procedure and during the 12 months post-activation.
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Affiliation(s)
- David Schramm
- Department of Otolaryngology - Head and Neck Surgery, University of Ottawa , Ottawa, Canada
| | - Joseph Chen
- Department ofOtolaryngology- Head & Neck Surgery, Sunnybrook Hospital , Toronto, Canada
| | - David P Morris
- Division of Otolaryngology -Head & Neck Surgery, Continuing Professional Development, Dalhousie University , Halifax, Canada
| | - Nael Shoman
- Division of ENT, Head and Neck Surgery, Royal University Hospital , Saskatoon, Canada
| | - Daniel Philippon
- Département d'ophtalmologie et d'oto-rhino-laryngologie - chirurgie cervico-faciale, Quebec University Hospital , Quebec, Canada
| | - Per Cayé-Thomasen
- Afdeling for Øre-Næse-Halskirurgi og Audiologi, Copenhagen University Hospital Rigshospitalet , Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen, Denmark
| | - Michel Hoen
- Clinical Evidence, Oticon Medical , Smørum, Denmark
| | | | - Ariane Laplante-Lévesque
- Clinical Evidence, Oticon Medical , Smørum, Denmark.,Department of Behavioural Sciences and Learning, Linköping University , Linköping, Sweden
| | - Dan Gnansia
- Research & Technology, Oticon Medical , Smørum, Denmark
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Quass GL, Baumhoff P, Gnansia D, Stahl P, Kral A. Level coding by phase duration and asymmetric pulse shape reduce channel interactions in cochlear implants. Hear Res 2020; 396:108070. [PMID: 32950954 DOI: 10.1016/j.heares.2020.108070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/21/2020] [Accepted: 08/31/2020] [Indexed: 10/23/2022]
Abstract
Conventional loudness coding with CIs by pulse current amplitude has a disadvantage: Increasing the stimulation current increases the spread of excitation in the auditory nerve, resulting in stronger channel interactions at high stimulation levels. These limit the number of effective information channels that a CI user can perceive. Stimulus intensity information (loudness) can alternatively be transmitted via pulse phase duration. We hypothesized that loudness coding by phase duration avoids the increase in the spread of the electric field and thus leads to less channel interactions at high stimulation levels. To avoid polarity effects, we combined this coding with pseudomonophasic stimuli. To test whether this affects the spread of excitation, 16 acutely deafened guinea pigs were implanted with CIs and neural activity from the inferior colliculus was recorded while stimulating with either biphasic, amplitude-coded pulses, or pseudomonophasic, duration- or amplitude-coded pulses. Pseudomonophasic stimuli combined with phase duration loudness coding reduced the lowest response thresholds and the spread of excitation. We investigated the channel interactions at suprathreshold levels by computing the phase-locking to a pulse train in the presence of an interacting pulse train on a different electrode on the CI. Pseudomonophasic pulses coupled with phase duration loudness coding reduced the interference by 4-5% compared to biphasic pulses, depending on the place of stimulation. This effect of pseudomonophasic stimuli was achieved with amplitude coding only in the basal cochlea, indicating a distance- or volume dependent effect. Our results show that pseudomonophasic, phase-duration-coded stimuli slightly reduce channel interactions, suggesting a potential benefit for speech understanding in humans.
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Affiliation(s)
- Gunnar Lennart Quass
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177).
| | - Peter Baumhoff
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany
| | | | | | - Andrej Kral
- Institute for AudioNeuroTechnology (VIANNA), ENT Clinics, Hannover Medical School, 30625 Hannover, Germany; Cluster of Excellence "Hearing4All" (EXC 2177)
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Tanaka Massuda E, Demarcy T, Hoen M, Danieli F, Arantes do Amaral MS, Gnansia D, Hyppolito MA. Method to quantitatively assess electrode migration from medical images: Feasibility and application in patients with straight cochlear implant arrays. Cochlear Implants Int 2019; 20:237-241. [PMID: 31138089 DOI: 10.1080/14670100.2019.1618525] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Objective: To propose a method for quantitative assessment of the migration of lateral-wall, straight electrode arrays after surgery based on postoperative Cone Beam Computed Tomography (CBCT) images and automated medical image analysis techniques. Methods: A preliminary study is conducted on 19 implanted ears. For each implantation, two CBCT images are objectively analyzed. Electrode arrays are consistently projected into the same coordinate system in order to estimate precisely the migration of each electrode. Spatial configuration changes are characterized with the overall curvature of the electrode array. Results: From the samples analyzed no significant electrode migration, extrusion or electrode curvature changes were found. Mean infinitesimal local migration reveals a tendency where apical electrodes tend to move away from the modiolus and basal electrodes away from the round window. Conclusion: CBCT images demonstrate adequate resolution with limited artifacts to assess the electrode array position in vivo. Automated medical image analysis techniques and consistent coordinate system allow to quantitatively estimate migration and extrusion effect for lateral-wall, straight electrode array.
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Affiliation(s)
- Eduardo Tanaka Massuda
- a Department of Ophthalmology, Otorhinolaryngology, Head and Neck Surgery, Ribeirão Preto Medical School , University of São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Thomas Demarcy
- b Department of Scientific and Clinical Research , Oticon Medical , Vallauris , France
| | - Michel Hoen
- b Department of Scientific and Clinical Research , Oticon Medical , Vallauris , France
| | - Fabiana Danieli
- c Clinical Department , Oticon Medical , São Paulo , Brazil.,d Postgraduate Program at the Department of Ophthalmology , Otorhinolaryngology, Head and Neck Surgery , Ribeirão Preto , Brazil
| | - Maria Stella Arantes do Amaral
- a Department of Ophthalmology, Otorhinolaryngology, Head and Neck Surgery, Ribeirão Preto Medical School , University of São Paulo , Ribeirão Preto, São Paulo , Brazil.,d Postgraduate Program at the Department of Ophthalmology , Otorhinolaryngology, Head and Neck Surgery , Ribeirão Preto , Brazil
| | - Dan Gnansia
- b Department of Scientific and Clinical Research , Oticon Medical , Vallauris , France
| | - Miguel Angelo Hyppolito
- a Department of Ophthalmology, Otorhinolaryngology, Head and Neck Surgery, Ribeirão Preto Medical School , University of São Paulo , Ribeirão Preto, São Paulo , Brazil
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Adenis V, Gourévitch B, Mamelle E, Recugnat M, Stahl P, Gnansia D, Nguyen Y, Edeline JM. ECAP growth function to increasing pulse amplitude or pulse duration demonstrates large inter-animal variability that is reflected in auditory cortex of the guinea pig. PLoS One 2018; 13:e0201771. [PMID: 30071005 PMCID: PMC6072127 DOI: 10.1371/journal.pone.0201771] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/21/2018] [Indexed: 12/20/2022] Open
Abstract
Despite remarkable advances made to ameliorate how cochlear implants process the acoustic environment, many improvements can still be made. One of most fundamental questions concerns a strategy to simulate an increase in sound intensity. Psychoacoustic studies indicated that acting on either the current, or the duration of the stimulating pulses leads to perception of changes in how loud the sound is. The present study compared the growth function of electrically evoked Compound Action Potentials (eCAP) of the 8th nerve using these two strategies to increase electrical charges (and potentially to increase the sound intensity). Both with chronically (experiment 1) or acutely (experiment 2) implanted guinea pigs, only a few differences were observed between the mean eCAP amplitude growth functions obtained with the two strategies. However, both in chronic and acute experiments, many animals showed larger increases of eCAP amplitude with current increase, whereas some animals showed larger of eCAP amplitude with duration increase, and other animals show no difference between either approaches. This indicates that the parameters allowing the largest increase in eCAP amplitude considerably differ between subjects. In addition, there was a significant correlation between the strength of neuronal firing rate in auditory cortex and the effect of these two strategies on the eCAP amplitude. This suggests that pre-selecting only one strategy for recruiting auditory nerve fibers in a given subject might not be appropriate for all human subjects.
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Affiliation(s)
- Victor Adenis
- Paris-Saclay Institute of Neurosciences (Neuro-PSI) Université Paris-Sud, Orsay, France
- CNRS UMR 9197, Orsay, France
- Université Paris-Saclay, Orsay, France
| | - Boris Gourévitch
- Paris-Saclay Institute of Neurosciences (Neuro-PSI) Université Paris-Sud, Orsay, France
- CNRS UMR 9197, Orsay, France
- Université Paris-Saclay, Orsay, France
| | | | | | | | | | - Yann Nguyen
- INSERM UMR-S-1159, Paris, France
- Université Paris-VI, Paris, France
| | - Jean-Marc Edeline
- Paris-Saclay Institute of Neurosciences (Neuro-PSI) Université Paris-Sud, Orsay, France
- CNRS UMR 9197, Orsay, France
- Université Paris-Saclay, Orsay, France
- * E-mail:
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Gehrke M, Verin J, Gnansia D, Tourrel G, Risoud M, Vincent C, Siepmann F, Siepmann J. Hybrid Ear Cubes for local controlled dexamethasone delivery to the inner ear. Eur J Pharm Sci 2018; 126:23-32. [PMID: 29723597 DOI: 10.1016/j.ejps.2018.04.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 04/18/2018] [Accepted: 04/29/2018] [Indexed: 01/13/2023]
Abstract
A new type of miniaturized implants for local controlled drug delivery to the inner ear is proposed: Hybrid Ear Cubes. They are composed of two main parts: (i) a cylinder, which is placed into a tiny hole (<0.4 mm) drilled into (or close to) the oval (or round) window, and (ii) a cuboid, which is placed into the middle ear. The drug is released at a pre-programmed rate into the perilymph: (i) via the cylindrical part of the implant, which is in direct contact with this liquid, and (ii) via diffusion from the cuboid through the oval/round window. Importantly, the cylindrical part assures a reliable fixation of the drug delivery system at the site of administration. Furthermore, the cuboid provides a relatively "large" drug reservoir, without expulsing perilymph from the cochlea. The required surgery is minimized compared to the placement of an intracochlear implant. In contrast to previously proposed Ear Cubes, which are mono-block systems, Hybrid Ear Cubes consist of two halves, which can: (i) be loaded with different drugs, (ii) be loaded with the same drug at different concentrations, and/or (iii) be based on two different matrix formers. This offers a substantially increased formulation flexibility. Different types of silicone-based Hybrid Ear Cubes were prepared, loaded with 10% dexamethasone in one half and 0-60% dexamethasone in the other half. Importantly, tiny drug crystals were homogeneously distributed throughout the respective implant halves. The observed drug release rates were very low (e.g., <0.5% after 2 months), which can be attributed to the type of drug and silicone as well as to the very small surface area exposed to the release medium. Importantly, no noteworthy implant swelling was observed.
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Affiliation(s)
- M Gehrke
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Verin
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - D Gnansia
- Oticon Medical/Neurelec, R&D, 2720 Chemin Saint-Bernard, F-06224 Vallauris, France
| | - G Tourrel
- Oticon Medical/Neurelec, R&D, 2720 Chemin Saint-Bernard, F-06224 Vallauris, France
| | - M Risoud
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - C Vincent
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - F Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France
| | - J Siepmann
- Univ. Lille, Inserm, CHU Lille, U1008, F-59000 Lille, France.
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Gehrke M, Sircoglou J, Gnansia D, Tourrel G, Willart JF, Danede F, Lacante E, Vincent C, Siepmann F, Siepmann J. Ear Cubes for local controlled drug delivery to the inner ear. Int J Pharm 2016; 509:85-94. [DOI: 10.1016/j.ijpharm.2016.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 02/06/2023]
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Gnansia D, Demarcy T, Vandersteen C, Raffaelli C, Guevara N, Delingette H, Ayache N. Optimal electrode diameter in relation to volume of the cochlea. Eur Ann Otorhinolaryngol Head Neck Dis 2016; 133 Suppl 1:S66-7. [DOI: 10.1016/j.anorl.2016.04.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/28/2016] [Indexed: 11/16/2022]
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Guevara N, Bozorg-Grayeli A, Bebear JP, Ardoint M, Saaï S, Gnansia D, Hoen M, Romanet P, Lavieille JP. The Voice Track multiband single-channel modified Wiener-filter noise reduction system for cochlear implants: patients' outcomes and subjective appraisal. Int J Audiol 2016; 55:431-8. [DOI: 10.3109/14992027.2016.1172267] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Nicolas Guevara
- CHU de Nice, University Head and Neck Institute, Nice, France,
| | - Alexis Bozorg-Grayeli
- Department of Head and Neck Surgery, CHU - University Hospital of Dijon, Dijon, France,
| | - Jean-Pierre Bebear
- ENT Department, Pellegrin Hospital, University of Bordeaux, Bordeaux, France,
| | - Marine Ardoint
- Clinical and Scientific Research Department, Oticon Medical - Neurelec, Vallauris, France, and
| | - Sonia Saaï
- Clinical and Scientific Research Department, Oticon Medical - Neurelec, Vallauris, France, and
| | - Dan Gnansia
- Clinical and Scientific Research Department, Oticon Medical - Neurelec, Vallauris, France, and
| | - Michel Hoen
- Clinical and Scientific Research Department, Oticon Medical - Neurelec, Vallauris, France, and
| | - Philippe Romanet
- Department of Head and Neck Surgery, CHU - University Hospital of Dijon, Dijon, France,
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Bento RF, Danieli F, Magalhães ATDM, Gnansia D, Hoen M. Residual Hearing Preservation with the Evo® Cochlear Implant Electrode Array: Preliminary Results. Int Arch Otorhinolaryngol 2016; 20:353-358. [PMID: 27746839 PMCID: PMC5063727 DOI: 10.1055/s-0036-1572530] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/15/2015] [Indexed: 10/25/2022] Open
Abstract
Introduction The preservation of residual hearing is currently an important challenge for cochlear implant surgeries. Indeed, if patients exhibit functional hearing after cochlear implantation, they can benefit from the combination of acoustical stimulation, usually in the low-frequencies and electrical stimulation in the high-frequencies. This combined mode of stimulation has proven to be beneficial both in terms of speech perception and of sound quality. Finding the right procedures for conducting soft-surgeries and designing electrode arrays dedicated to hearing preservation is an open issue. Objective The objective of this study is to evaluate the combination of a soft-surgery procedure implicating round-window insertion and the use of dexamethasone and hyaluronic acid during surgery, with the use of a specifically designed straight soft electrode array, on hearing preservation in patients with functional hearing in the low frequencies. Methods This pre-clinical trial was conducted on seven patients with residual hearing in the low frequencies. The surgical method used employed a round window insertion and the use of topical dexamethasone. Results The soft-surgery protocol could be successfully followed in five patients. In this group, the average hearing threshold shift compared with pre-operative values was of 18.7 +/- 16.1 dB HL up to 500 Hz and 15.7 +/- 15.1 up to 1 kHz, demonstrating satisfying levels of hearing preservation. Conclusion We were able to demonstrate the possibility of preserving residual hearing in most of the patients using the EVO electrode. Significant residual hearing preservation levels were was obtained when a soft surgical approach involving round window insertion, dexamethasone and hyaluronic use during the surgery.
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Affiliation(s)
| | | | | | - Dan Gnansia
- Department of Scientific and Clinical Research, Oticon Medical, Vallauris, France
| | - Michel Hoen
- Department of Scientific and Clinical Research, Oticon Medical, Vallauris, France
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Bozorg-Grayeli A, Guevara N, Bebear JP, Ardoint M, Saaï S, Hoen M, Gnansia D, Romanet P, Lavieille JP. Clinical evaluation of the xDP output compression strategy for cochlear implants. Eur Arch Otorhinolaryngol 2015; 273:2363-71. [PMID: 26476927 DOI: 10.1007/s00405-015-3796-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
Technological advances in the domain of digital signal processing adapted to cochlear implants (CI) are partially responsible for the ever-improving outcomes observed with this neural prosthesis. The goal of the present study was to evaluate audiometric outcomes with a new signal processing strategy implemented in Oticon Medical-Neurelec cochlear implant systems, the xDP strategy. The core of this approach is a preset-based back-end output compression system, modulating a multi-channel transfer function depending on the intensity and information content of input sounds. Twenty adult CI patients, matched for age and CI experience, were included in this study. Pure-tone thresholds and vocal audiometry scores were measured with their former signal processing strategy and with xDP. Speech perception was assessed using dissyllabic words presented in quiet, at different intensity levels: 40, 55, 70, and 85 dB SPL, and in a cocktail party noise at a signal-to-noise ratio of +10 dB. Results with the xDP strategy showed, as awaited, no major modification of pure-tone thresholds. A global increase of speech perception scores was observed after a 1-month habituation period, with significant improvements for speech perception in quiet for moderate (55 dB SPL), loud speech sounds (85 dB SPL), and speech-in-noise comprehension. Subjective signal quality assessment showed a preference for Crystalis(xDP) over the former strategy. These results allow the quantification of improvements provided by the xDP signal processing strategy.
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Affiliation(s)
- Alexis Bozorg-Grayeli
- Department of Head and Neck Surgery, CHU-University Hospital of Dijon, Dijon, France
| | - Nicolas Guevara
- University Head and Neck Institute, CHU de Nice, Nice, France
| | - Jean-Pierre Bebear
- ENT Department, Pellegrin Hospital, University of Bordeaux, Bordeaux, France
| | - Marine Ardoint
- Clinical and Scientific Research Department, Oticon Medical-Neurelec, 2720 Chemin Saint Bernard, 06220, Vallauris, France
| | - Sonia Saaï
- Clinical and Scientific Research Department, Oticon Medical-Neurelec, 2720 Chemin Saint Bernard, 06220, Vallauris, France
| | - Michel Hoen
- Clinical and Scientific Research Department, Oticon Medical-Neurelec, 2720 Chemin Saint Bernard, 06220, Vallauris, France.
| | - Dan Gnansia
- Clinical and Scientific Research Department, Oticon Medical-Neurelec, 2720 Chemin Saint Bernard, 06220, Vallauris, France
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Borger D, Lina-Granade G, Verneyre S, Thai-Van H, Saaï S, Hoen M, Gnansia D, Truy E. One-Year Follow Up of Auditory Performance in Post-Lingually Deafened Adults Implanted with the Neurelec Digisonic(®) SP/Saphyr(®) Neo Cochlear Implant System. Audiol Res 2015; 5:139. [PMID: 26779331 PMCID: PMC4698604 DOI: 10.4081/audiores.2015.139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/01/2015] [Indexed: 11/30/2022] Open
Abstract
This study aimed to quantify outcomes in a group of patients who were implanted with an Oticon Medical Neurelec (Vallauris, France) cochlear implant system, the Digisonic® SP/Saphyr® Neo. Ten participants took part in this preliminary study. Their speech perception capacities were evaluated at 3, 6, and 12-months after cochlear implant activation and compared to pre-implantation scores and to scores observed with former versions of the sound processor. Compared to former versions of the sound processor, patients using the Saphyr® Neo processor obtained better speech perception scores for sentences in silence at each tests session (3 months: 79%, 6 months: 82% and 12 months: 94%) compared to Digisonic® users (respectively: 58%, 69% and 75%) and Convex sound processor users (resp. 39%, 59% and 51%). These observations confirm that the technological improvements made in the Saphyr® Neo sound processor coupled with the Digisonic® implant, provided quantifiable benefits in speech perception in Quiet compared to former versions of the processor Convex and Digisonic® SP.
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Affiliation(s)
| | | | | | | | - Sonia Saaï
- Oticon Medical - Neurelec , Vallauris, France
| | - Michel Hoen
- Oticon Medical - Neurelec , Vallauris, France
| | - Dan Gnansia
- Oticon Medical - Neurelec , Vallauris, France
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Cabrera L, Tsao FM, Gnansia D, Bertoncini J, Lorenzi C. The role of spectro-temporal fine structure cues in lexical-tone discrimination for French and Mandarin listeners. J Acoust Soc Am 2014; 136:877-882. [PMID: 25096121 DOI: 10.1121/1.4887444] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The role of spectro-temporal modulation cues in conveying tonal information for lexical tones was assessed in native-Mandarin and native-French adult listeners using a lexical-tone discrimination task. The fundamental frequency (F0) of Thai tones was either degraded using an 8-band vocoder that reduced fine spectral details and frequency-modulation cues, or extracted and used to modulate the F0 of click trains. Mandarin listeners scored lower than French listeners in the discrimination of vocoded lexical tones. For click trains, Mandarin listeners outperformed French listeners. These preliminary results suggest that the perceptual weight of the fine spectro-temporal modulation cues conveying F0 information is enhanced for adults speaking a tonal language.
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Affiliation(s)
- Laurianne Cabrera
- Laboratoire de Psychologie de la Perception, CNRS, Université Paris Descartes, 45 rue des saints Pères, 75006 Paris, France
| | - Feng-Ming Tsao
- Department of Psychology, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 106, Taiwan
| | - Dan Gnansia
- Neurelec, 2720 Chemin de Saint-Bernard Porte, 06224, Vallauris, France
| | - Josiane Bertoncini
- Laboratoire de Psychologie de la Perception, CNRS, Université Paris Descartes, 45 rue des saints Pères, 75006 Paris, France
| | - Christian Lorenzi
- Laboratoire des systèmes perceptifs, CNRS, Institut d'Etude de la Cognition, Ecole normale supérieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France
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Guevara N, Atean I, Benoit D, Pointreau Y, Angellier G, Marcie S, Saaï S, Gnansia D, Thariat J. Effects and consequences of Digisonic SP cochlear implant on radiotherapy planning. Eur Arch Otorhinolaryngol 2014; 272:1597-603. [PMID: 24599596 DOI: 10.1007/s00405-014-2949-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 02/08/2014] [Indexed: 10/25/2022]
Abstract
The aim of this study was to assess dose attenuation by a Digisonic SP cochlear implant (CI) and evaluate its impact on treatment planning. The Digisonic CI was irradiated with 6 MV photons. Overall dose attenuation was assessed with MOSFET dosimeters and Gafchromic films. In addition, we evaluated the attenuation of separate CI components. Dose attenuation was also calculated using different radiation treatment planning systems (TPS) softwares and dose calculation algorithms. The CI was placed on a head phantom. Single-beam and multiple-beam plans were evaluated for dose attenuation using two radiation techniques (Conformal and Stereotactic radiotherapy) and four different algorithms (Clarkson, Point Kernel-Superposition, Ray Tracing and Monte Carlo). MOSFET and Gafchromics film showed maximal 6-7.5% radiation dose attenuation, at the center of the CI. Computerized TPS-based dose attenuation by the implant was 4-8.1%, using a single ipsilateral field. No clinically meaningful dose attenuation was found in multiple field plans owing to the contribution of various beam paths with only a couple going through the implant using either conventional conformal or stereotactic treatment plans. Dose attenuation induced by a Digisonic SP CI is about 6%, for single 6 MV photon field. This dose reduction is unlikely to be clinically significant, as single-field radiotherapy plans to this anatomic region are uncommon.
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Affiliation(s)
- Nicolas Guevara
- Department of Head and Neck Surgery, University Center-Institut Universitaire de la Face et du Cou, 33 Av. Valombrose, 06189, Nice Cedex 2, France,
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Vaerenberg B, Péan V, Lesbros G, De Ceulaer G, Schauwers K, Daemers K, Gnansia D, Govaerts PJ. Combined electric and acoustic hearing performance with Zebra®speech processor: Speech reception, place, and temporal coding evaluation. Cochlear Implants Int 2013; 14:150-7. [DOI: 10.1179/1754762812y.0000000008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Gnansia D, Lazard DS, Léger AC, Fugain C, Lancelin D, Meyer B, Lorenzi C. Role of slow temporal modulations in speech identification for cochlear implant users. Int J Audiol 2013; 53:48-54. [PMID: 24195655 DOI: 10.3109/14992027.2013.844367] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study aimed to assess whether the capacity of cochlear implant (CI) users to identify speech is determined by their capacity to perceive slow (< 20 Hz) temporal modulations. DESIGN This was achieved by studying the correlation between (1) phoneme identification in quiet and in a steady-state or fluctuating (8 Hz) noises, and (2) amplitude-modulation detection thresholds (MDTs) at 8 Hz (i.e. slow temporal modulations). STUDY SAMPLE Twenty-one CI users, unilaterally implanted with the same device, were tested in free field with their everyday clinical processor. RESULTS Extensive variability across subjects was observed for both phoneme identification and MDTs. Vowel and consonant identification scores in quiet were significantly correlated with MDTs at 8 Hz (r = - 0.47 for consonants, r = - 0.44 for vowels; p < 0.05). When the masker was a steady-state noise, only consonant identification scores tended to correlate with MDTs at 8 Hz (r = - 0.4; p = 0.07). When the masker was a fluctuating noise, consonant and vowel identification scores were not significantly correlated with MDTs at 8 Hz. CONCLUSIONS Sensitivity to slow amplitude modulations is correlated with vowel and consonant perception in CI users. However, reduced sensitivity to slow modulations does not entirely explain the limited capacity of CI recipients to understand speech in noise.
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Lorenzi C, Wallaert N, Gnansia D, Leger AC, Ives DT, Chays A, Garnier S, Cazals Y. Temporal-envelope reconstruction for hearing-impaired listeners. J Assoc Res Otolaryngol 2012; 13:853-65. [PMID: 23007719 PMCID: PMC3505588 DOI: 10.1007/s10162-012-0350-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 09/09/2012] [Indexed: 10/27/2022] Open
Abstract
Recent studies suggest that normal-hearing listeners maintain robust speech intelligibility despite severe degradations of amplitude-modulation (AM) cues, by using temporal-envelope information recovered from broadband frequency-modulation (FM) speech cues at the output of cochlear filters. This study aimed to assess whether cochlear damage affects this capacity to reconstruct temporal-envelope information from FM. This was achieved by measuring the ability of 40 normal-hearing listeners and 41 listeners with mild-to-moderate hearing loss to identify syllables processed to degrade AM cues while leaving FM cues intact within three broad frequency bands spanning the range 65-3,645 Hz. Stimuli were presented at 65 dB SPL for both normal-hearing listeners and hearing-impaired listeners. They were presented as such or amplified using a modified half-gain rule for hearing-impaired listeners. Hearing-impaired listeners showed significantly poorer identification scores than normal-hearing listeners at both presentation levels. However, the deficit shown by hearing-impaired listeners for amplified stimuli was relatively modest. Overall, hearing-impaired data and the results of a simulation study were consistent with a poorer-than-normal ability to reconstruct temporal-envelope information resulting from a broadening of cochlear filters by a factor ranging from 2 to 4. These results suggest that mild-to-moderate cochlear hearing loss has only a modest detrimental effect on peripheral, temporal-envelope reconstruction mechanisms.
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Affiliation(s)
- Christian Lorenzi
- Equipe Audition (CNRS, Universite Paris Descartes, Ecole normale superieure), Institut d'Etude de la Cognition, Ecole normale superieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France.
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Verhaert N, Lazard DS, Gnansia D, Bébéar JP, Romanet P, Meyer B, Péan V, Mollard D, Truy E. Speech performance and sound localization abilities in Neurelec Digisonic® SP binaural cochlear implant users. Audiol Neurootol 2012; 17:256-66. [PMID: 22584289 DOI: 10.1159/000338472] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 03/12/2012] [Indexed: 11/19/2022] Open
Abstract
In this prospective study the outcome of the Digisonic® SP Binaural cochlear implant (CI), a device enabling electric stimulation of both cochleae by a single receiver, was evaluated in 14 postlingually deafened adults after 12 months of use. Speech perception was tested using French disyllabic words in quiet and in speech-shaped noise at +10 dB signal-to-noise ratio. Horizontal sound localization in quiet was tested using pink noise coming from 5 loudspeakers, from -90 to +90° along the azimuth. Speech scores in quiet were 76% (±19.5 SD) in the bilateral condition, 62% (±24 SD) for the better ear alone and 43.5% (±27 SD) for the poorer ear alone. Speech scores in noise were 60% (±27.5 SD), 46% (±28 SD) and 28% (±25 SD), respectively, in the same conditions. Statistical analysis showed a significant advantage of the bilateral use in quiet and in noise (p < 0.05 compared to the better ear). Significant spatial perception benefits such as summation effect (p < 0.05), head shadow effect (p < 0.0001) and squelch effect (p < 0.0005) were noted. Sound localization accuracy improved significantly when using the device in the bilateral condition with an average root mean square of 35°. Compared with published outcomes of usual bilateral cochlear implantation, this device could be a valuable alternative to two CIs. Prospective controlled trials, comparing the Digisonic SP Binaural CI with a standard bilateral cochlear implantation are mandatory to evaluate their respective advantages and cost-effectiveness.
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Affiliation(s)
- Nicolas Verhaert
- Département d'ORL, de Chirurgie Cervico-Maxillo-Faciale, et d'Audiophonologie, Hospices Civils de Lyon, Hôpital Edouard Herriot, Lyon, France.
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Léger AC, Moore BCJ, Gnansia D, Lorenzi C. Effects of spectral smearing on the identification of speech in noise filtered into low- and mid-frequency regions. J Acoust Soc Am 2012; 131:4114-4123. [PMID: 22559383 DOI: 10.1121/1.3699265] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Léger et al. [J. Acoust. Soc. Am. 131, 1502-1514 (2012)] reported deficits in the identification of consonants in noise by hearing-impaired listeners using stimuli filtered into low- or mid-frequency regions in which audiometric thresholds were normal or near-normal. The deficits could not be fully explained in terms of reduced audibility or temporal-envelope processing. However, previous studies indicate that the listeners may have had reduced frequency selectivity, with auditory filters broadened by a factor of about 1.3, despite having normal or near-normal audiometric thresholds in the tested regions. The present study aimed to determine whether the speech-perception deficits could be explained by such a small reduction of frequency selectivity. Consonant identification was measured for normal-hearing listeners in quiet and in unmodulated and modulated noises using the same method as Léger et al. The signal-to-noise ratio was set to -3 dB for the masked conditions. Various amounts of reduced frequency selectivity were simulated using a spectral-smearing algorithm. Performance was reduced only for spectral-smearing factors greater than 1.7. For all conditions, identification scores for hearing-impaired listeners could not be explained by a mild reduction of frequency selectivity.
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Affiliation(s)
- Agnès C Léger
- Equipe Audition, Institut d'Etudes Cognitives, École Normale Supérieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France.
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Lazard D, Giraud AL, Gnansia D, Meyer B, Sterkers O. Understanding the deafened brain: Implications for cochlear implant rehabilitation. Eur Ann Otorhinolaryngol Head Neck Dis 2012; 129:98-103. [PMID: 22104578 DOI: 10.1016/j.anorl.2011.06.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 04/21/2011] [Accepted: 06/21/2011] [Indexed: 10/15/2022]
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Krenzlin S, Vincent C, Munzke L, Gnansia D, Siepmann J, Siepmann F. Predictability of drug release from cochlear implants. J Control Release 2011; 159:60-8. [PMID: 22233971 DOI: 10.1016/j.jconrel.2011.12.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 12/19/2011] [Accepted: 12/22/2011] [Indexed: 11/17/2022]
Abstract
A simplified mathematical theory is presented allowing for in silico simulation of the effects of key parameters of miniaturized implants (size and composition) on the resulting drug release kinetics. Such devices offer a great potential, especially for local drug treatments, e.g. of the inner ear. However, the preparation and characterization of these systems is highly challenging, due to the small system dimensions. The presented mathematical theory is based on Fick's second law of diffusion. Importantly, theoretical predictions do not require the knowledge of many system-specific parameters: Only the "apparent" diffusion coefficient of the drug within the implant matrix is needed. This parameter can be easily determined via drug release measurements from thin, macroscopic films. The validity of the theoretical model predictions was evaluated by comparison with experimental results obtained with a cochlear implant. The latter consisted of miniaturized electrodes, which were embedded in a silicone matrix loaded with various amounts of dexamethasone. Importantly, independent experimental results confirmed the theoretical predictions. Thus, the presented simplified theory can help to significantly speed up the optimization of this type of controlled drug delivery systems, especially if long release periods are targeted (e.g., several months or years). Straightforward experiments with thin, macroscopic films and computer simulations can allow for rapid identification of optimal system design.
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Affiliation(s)
- S Krenzlin
- University of Lille, College of Pharmacy, 3 Rue du Prof. Laguesse, Lille, France
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Lazard DS, Bordure P, Lina-Granade G, Magnan J, Meller R, Meyer B, Radafy E, Roux PE, Gnansia D, Péan V, Truy E. Speech perception performance for 100 post-lingually deaf adults fitted with Neurelec cochlear implants: Comparison between Digisonic® Convex and Digisonic® SP devices after a 1-year follow-up. Acta Otolaryngol 2010; 130:1267-73. [PMID: 20446821 DOI: 10.3109/00016481003769972] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSION Patients implanted with the Digisonic® SP device showed better identification scores than those implanted with the Convex device, with skills continuing to improve over a longer time period. Technological improvements were beneficial in terms of speech perception in quiet. OBJECTIVE To compare speech perception skills for post-lingually deaf patients implanted with a previous Neurelec device, the Digisonic® Convex, with those implanted with a more recent one, the Digisonic® SP, which provides more electrodes and a faster stimulation rate. METHODS This was a retrospective study of 100 implanted patients, 45 with the Digisonic® Convex implant and 55 with the Digisonic® SP. Speech perception (dissyllabic words and sentences, in open set) was evaluated until 1 year after implantation. RESULTS Patients fitted with the Digisonic® SP implant showed significantly better scores after 3, 6, and 12 months (mean scores: 53%, 62%, and 68% for words; 58%, 69%, and 75% for sentences) than those fitted with the Convex implant (34%, 42%, and 43% for words; 38%, 59%, and 51% for sentences). The improvement in speech perception after implantation for SP patients continued throughout the 12 months for words and 6 months for sentences, versus 6 months for words and 3 months for sentences for Convex patients.
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Gnansia D, Pressnitzer D, Péan V, Meyer B, Lorenzi C. Intelligibility of interrupted and interleaved speech for normal-hearing listeners and cochlear implantees. Hear Res 2010; 265:46-53. [DOI: 10.1016/j.heares.2010.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 02/15/2010] [Accepted: 02/24/2010] [Indexed: 12/31/2022]
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Gnansia D, Péan V, Meyer B, Lorenzi C. Effects of spectral smearing and temporal fine structure degradation on speech masking release. J Acoust Soc Am 2009; 125:4023-33. [PMID: 19507983 DOI: 10.1121/1.3126344] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This study assessed the effects of spectral smearing and temporal fine structure (TFS) degradation on masking release (MR) (the improvement in speech identification in amplitude-modulated compared to steady noise observed for normal-hearing listeners). Syllables and noise stimuli were processed using either a spectral-smearing algorithm or a tone-excited vocoder. The two processing schemes simulated broadening of the auditory filters by factors of 2 and 4. Simulations of the early stages of auditory processing showed that the two schemes produced comparable excitation patterns; however, fundamental frequency (F0) information conveyed by TFS was degraded more severely by the vocoder than by the spectral-smearing algorithm. Both schemes reduced MR but, for each amount of spectral smearing, the vocoder produced a greater reduction in MR than the spectral-smearing algorithm, consistent with the effects of each scheme on F0 representation. Moreover, the effects of spectral smearing on MR produced by the two schemes were different for manner and voicing. Finally, MR data for listeners with moderate hearing loss were well matched by MR data obtained for normal-hearing listeners with vocoded stimuli, suggesting that impaired frequency selectivity alone may not be sufficient to account for the reduced MR observed for hearing-impaired listeners.
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Affiliation(s)
- Dan Gnansia
- Laboratoire de Psychologie de la Perception, Universite Paris Descartes, UMR CNRS 8158, Ecole Normale Superieure, Paris, France.
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