Effects of Electrode Array Length on Frequency-Place Mismatch and Speech Perception with Cochlear Implants

2015 ◽  
Vol 20 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Frederic Venail ◽  
Caroline Mathiolon ◽  
Sophie Menjot de Champfleur ◽  
Jean Pierre Piron ◽  
Marielle Sicard ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implants ◽  
Cochlear Implantation ◽  
Electrode Array ◽  
Electrode Arrays ◽  
Frequency Map

Frequency-place mismatch often occurs after cochlear implantation, yet its effect on speech perception outcome remains unclear. In this article, we propose a method, based on cochlea imaging, to determine the cochlear place-frequency map. We evaluated the effect of frequency-place mismatch on speech perception outcome in subjects implanted with 3 different lengths of electrode arrays. A deeper insertion was responsible for a larger frequency-place mismatch and a decreased and delayed speech perception improvement by comparison with a shallower insertion, for which a similar but slighter effect was noticed. Our results support the notion that selecting an electrode array length adapted to each individual's cochlear anatomy may reduce frequency-place mismatch and thus improve speech perception outcome.

scholarly journals Restoration of High Frequency Auditory Perception After Robot-Assisted or Manual Cochlear Implantation in Profoundly Deaf Adults Improves Speech Recognition

2021 ◽  
Vol 8 ◽  
Author(s):  
Renato Torres ◽  
Hannah Daoudi ◽  
Ghizlene Lahlou ◽  
Olivier Sterkers ◽  
Evelyne Ferrary ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implantation ◽  
High Frequency ◽  
Pure Tone ◽  
Free Field ◽  
Electrode Array ◽  
Electrode Arrays ◽  
Robot Assisted ◽  
Deaf Adults ◽  
Post Implantation

Background and Purpose: Robot-assisted cochlear implantation has recently been implemented in clinical practice; however, its effect on hearing outcomes is unknown. The aim of this preliminary study was to evaluate hearing performance 1 year post-implantation whether the electrode array was inserted manually or assisted by a robot.Methods: Forty-two profoundly deaf adults were implanted either manually (n = 21) or assisted by a robot (RobOtol®, Collin, Bagneux, France) with three different electrode array types. Participants were paired by age, and electrode array type. The scalar position of the electrode array in the cochlea was assessed by 3D reconstruction from the pre- and post-implantation computed tomography. Pure-tone audiometry and speech perception in silence (percentage of disyllabic words at 60 dB) were tested on the implanted ear 1 year post-implantation in free-field conditions. The pure-tone average was calculated at 250–500–750 Hz, 500–1,000–2,000–3,000 Hz, and 3,000–4,000–8,000 Hz for low, mid, and high frequencies, respectively.Results: One year after cochlear implantation, restoration of the high-frequency thresholds was associated with better speech perception in silence, but not with low or mid frequencies (p < 0.0001; Adjusted R2 = 0.64, polynomial non-linear regression). Although array translocation was similar using either technique, the number of translocated electrodes was lower when the electrode arrays had been inserted with the assistance of the robot compared with manual insertion (p = 0.018; Fisher's exact test).Conclusion: The restoration of high-frequency thresholds (3,000–4,000–8,000 Hz) by cochlear implantation was associated with good speech perception in silence. The numbers of translocated electrodes were reduced after a robot-assisted insertion.

Radiology for cochlear implants

1991 ◽  
Vol 105 (2) ◽  
pp. 85-88 ◽  
Author(s):  
R. F. Gray ◽  
R. A. Evans ◽  
C. E. L. Freer ◽  
H. E. Szutowicz ◽  
G. F. Maskell
Keyword(s):  
Cochlear Implants ◽  
Electrode Array ◽  
Base Line ◽  
Maximum Information ◽  
Cochlear Duct ◽  
Plain Films ◽  
Hearing Result ◽  
Frequency Map ◽  
Inexperienced Surgeon ◽  
Multichannel Electrode

AbstractOne fifth of patients selected for cochlear implants have such bony irregularities in the cochlear duct that full insertion of a multichannel electrode array is impossible. Three cases of cochlear deafness are presented where pre- and post-operative radiology played an important part in the management.Standard CT at 2 mm cuts is compared with ultra high resolution CT at 1 mm cuts. The pitfall of poor definition is that the inexperienced surgeon may find himself unexpectedly drilling out an obliterated cochlear duct. Sections 30 degrees caudal to Reid's infra orbito-meatal base line at 1 mm intervals give maximum information for minimum radiation.Plain films show the placement of individual platinum electrode contacts in relation to the spiral ‘frequency map’ of the cochlea. This is vital information for the audiologist who has to route specific frequencies to specific sites within the ear for a good hearing result.

Cochlear Implantation with the CI512 and CI532 Precurved Electrode Arrays: One-Year Speech Recognition and Intraoperative Thresholds of Electrically Evoked Compound Action Potentials

2019 ◽  
Vol 24 (6) ◽  
pp. 299-308 ◽  
Author(s):  
Pernilla Videhult Pierre ◽  
Martin Eklöf ◽  
Henrik Smeds ◽  
Filip Asp
Keyword(s):  
Speech Recognition ◽  
Cochlear Implantation ◽  
Action Potentials ◽  
Electrode Array ◽  
University Hospital ◽  
Electrode Arrays ◽  
Neural Response Telemetry ◽  
Significant Difference ◽  
Compound Action Potentials ◽  
Compound Action

Introduction: Precurved cochlear implant (CI) electrode arrays were developed in an attempt to improve the auditory outcome of cochlear implantation, which varies greatly. The recent CI532 (Cochlear Corp., Sydney, Australia) may offer further advantages as its electrode array is thinner than previous precurved CI electrode arrays. The aims here were to investigate 1-year postoperative speech recognition, intraoperative electrically evoked compound action potentials (ECAPs), and their possible relation in patients implanted with a CI532 or its predecessor CI512. Methods: A retrospective analysis of data from 63 patients subjected to cochlear implantation at the Karolinska University Hospital, Sweden, was performed. Speech recognition of the implanted ear was evaluated using phonemically balanced monosyllabic Swedish words at 65 dB SPL. ECAPs were evaluated using the intraoperative ECAP threshold across ≥8 electrodes generated by the automated neural response telemetry of the CI. Results: The median aided speech recognition score (SRS) 1 year after implantation was 52% (quartile 1 = 40%, quartile 3 = 60%, n = 63) and did not differ statistically significantly between patients with CI512 (n = 38) and CI532 (n = 25). The mean ECAP threshold was 188 CL (current level; SD = 15 CL, n = 54) intraoperatively and did not differ statistically significantly between patients with CI512 (n = 32) and CI532 (n = 22), but the threshold for each electrode varied more between patients with a CI512 (p < 0.0001). A higher mean ECAP threshold was associated with a worse SRS (Spearman’s ρ = –0.46, p = 0.0004, n = 54). The association remained among those with a CI512 (Spearman’s ρ = –0.62, p = 0.0001, n = 32) when stratified by CI electrode array. Conclusion: No statistically significant difference in speech recognition 1 year after cochlear implantation or in mean threshold of ECAP intraoperatively was found between patients with a CI512 and the more recent, slim CI532, but the ECAP thresholds varied more between those with a CI512. A statistically significant association between SRS and mean ECAP threshold was found, but stratified analysis suggests that the association may be true only for patients with a CI512.

Fluoroscopy guided electrode-array insertion for cochlear implantation with straight electrode-arrays: a valuable tool in most cases

2020 ◽  
Author(s):  
Chiara Perazzini ◽  
Mathilde Puechmaille ◽  
Nicolas Saroul ◽  
Olivier Plainfossé ◽  
Laura Montrieul ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Electrode Array ◽  
Electrode Arrays

scholarly journals Factors Affecting Speech Discrimination in Children with Cochlear Implants: Evidence from Early-Implanted Infants

2016 ◽  
Vol 27 (06) ◽  
pp. 480-488 ◽  
Author(s):  
Jennifer Phan ◽  
Derek M. Houston ◽  
Chad Ruffin ◽  
Jonathan Ting ◽  
Rachael Frush Holt
Keyword(s):  
Speech Perception ◽  
Cochlear Implants ◽  
Cochlear Implantation ◽  
Pure Tone ◽  
Early Period ◽  
Discrimination Performance ◽  
Speech Discrimination ◽  
Communication Mode ◽  
Factors Affecting ◽  
Pure Tone Average

Background: To learn words and acquire language, children must be able to discriminate and correctly perceive phonemes. Although there has been much research on the general language outcomes of children with cochlear implants (CIs), little is known about the development of speech perception with regard to specific speech processes, such as speech discrimination. Purpose: The purpose of this study was to investigate the development of speech discrimination in infants with CIs and identify factors that might correlate with speech discrimination skills. Research Design: Using a Hybrid Visual Habituation procedure, we tested infants with CIs on their ability to discriminate the vowel contrast /i/-/u/. We also gathered demographic and audiological information about each infant. Study Sample: Children who had received CIs before 2 yr of age served as participants. We tested the children at two post cochlear implantation intervals: 2–4 weeks post CI stimulation (N = 17) and 6–9 mo post CI stimulation (N = 10). Data Collection and Analysis: The infants’ mean looking times during the novel versus old trials of the experiment were measured. A linear regression model was used to evaluate the relationship between the normalized looking time difference and the following variables: chronological age, age at CI stimulation, gender, communication mode, and best unaided pure-tone average. Results: We found that the best unaided pure-tone average predicted speech discrimination at the early interval. In contrast to some previous speech perception studies that included children implanted before 3 yr of age, age at CI stimulation did not predict speech discrimination performance. Conclusions: The results suggest that residual acoustic hearing before implantation might facilitate speech discrimination during the early period post cochlear implantation; with more hearing experience, communication mode might have a greater influence on the ability to discriminate speech. This and other studies on age at cochlear implantation suggest that earlier implantation might not have as large an effect on speech perception as it does on other language skills.

The Use of a Robot to Insert an Electrode Array of Cochlear Implants in the Cochlea: A Feasibility Study and Preliminary Results

2021 ◽  
pp. 1-7
Author(s):  
Sébastien Barriat ◽  
Nicolas Peigneux ◽  
Unal Duran ◽  
Severine Camby ◽  
Philippe P. Lefebvre
Keyword(s):  
Inner Ear ◽  
Cochlear Implants ◽  
Pure Tone ◽  
Cone Beam Ct ◽  
Surgical Techniques ◽  
Electrode Array ◽  
Pure Tone Audiometry ◽  
Cone Beam ◽  
Middle Ear Surgery ◽  
Electrode Arrays

<b><i>Introduction:</i></b> Cochlear implants (CIs) are commonly used for the rehabilitation of profound bilateral hearing loss. However, patients with substantial residual acoustic hearing are potential CI candidates. Because of both improvements in technology and advancements in surgical techniques, it may be possible to preserve hearing to some extent. For more than a decade, it has been suggested that robots are used to perform middle ear surgery. We evaluated the use of the RobOtol® otologic robot specifically to insert CI electrodes into the inner ear. <b><i>Methods:</i></b> CI surgery with the conventional approach was performed under general anesthesia. The MED-El Flex 24-electrode array was inserted using RobOtol®. Video recordings were used to calculate the speed of insertion. The positions of the electrodes were evaluated using a cone beam CT. All subjects underwent pure-tone audiometry tests before and after surgery, and the pure-tone average (PTA) was calculated from 250 to 4,000 Hz. <b><i>Results:</i></b> The robot inserted implants in 5 patients, and complete insertion of the electrode array was achieved. The speed of insertion of the electrode array was 0.88 ± 0.12 mm/s. The mean loss of the PTA for 5 frequencies (250, 500, 1,000, 2,000, and 4,000 Hz) was 13.60 ± 7.70 dB. Only 1 patient showed a loss of the PTA by &#x3e;20 dB. For these 5 patients, the cone beam CT findings showed that all the electrode arrays were in the tympanic ramp and had a grade of 0. The results were compared with those obtained from a cohort of 17 patients who underwent manual implantation of a MED-El Flex 24-electrode array. <b><i>Conclusion:</i></b> To minimize disturbance to the cochlea while atraumatic electrode arrays are inserted, electrodes can be inserted at a constant, slow speed in the inner ear with the assistance of the RobOtol® robot in a normal clinical surgical setting.

scholarly journals Round window versus conventional bony cochleostomy technique in pediatric cochlear implantation; A Randomized controlled double blinded trial.

2021 ◽  
Vol 7 (8) ◽  
pp. 1297
Author(s):  
Shama Shishodia ◽  
Dipu Saurav
Keyword(s):  
Speech Perception ◽  
Cochlear Implantation ◽  
Controlled Trial ◽  
Round Window ◽  
Electrode Arrays ◽  
Behavioral Threshold ◽  
Randomized Controlled ◽  
Auditory Performance ◽  
Auditory Integration ◽  
Double Blinded

<p><strong>Background:</strong> Objective of the study was to investigate the outcomes of cochlear implantation when done via two different techniques namely, the round window or the bony cochleostomy.</p><p><strong>Methods:</strong> A single-center, double-blinded randomized controlled trial including forty prelingual, bilateral severe to profoundly deaf children less than six years from the year 2014 to 2016 in a tertiary referral center in India were randomly allocated to round window and bony cochleostomy group. Our primary outcome measures were intraoperative neural response telemetry levels, behavioral threshold (t) and comfortable (c) loudness levels. The secondary subjective outcomes were measured via the category of auditory performance (CAP) and the meaningful auditory integration scale (MAIS) score. The cases were followed up for 9 months.</p><p><strong>Results:</strong> Intra-operative, electrically evoked compound action potentials (ECAP) showed comparable mean thresholds for both the techniques except intermediate electrodes (p~0.04) showed lower values for the round window. Similarly, a lower threshold (p~0.03) and comfortable mean current levels (p~0.03) were noticed for the round window group at 6 months post-implantation. Secondary speech perception outcome scores measured via category of auditory performance (CAP) and MAIS score were comparable. </p><p><strong>Conclusions:</strong> The round window insertion technique has physiological benefit as compared to the bony cochleostomy as evidenced by better stimulation levels in the intermediate electrodes and lower mean threshold and comfortable levels in the round window with more beneficial peri-modiolar position of electrode arrays. However, comparable speech perception outcomes revealed no clinical benefit in the cochlear implant performance depending on the technique of electrode insertion. </p>

Electrode Migration in Patients with Perimodiolar Cochlear Implant Electrodes

2015 ◽  
Vol 20 (6) ◽  
pp. 349-353 ◽  
Author(s):  
Philipp Mittmann ◽  
Grit Rademacher ◽  
Sven Mutze ◽  
Arneborg Ernst ◽  
Ingo Todt
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Electrode Array ◽  
Lateral Wall ◽  
Electrode Arrays ◽  
Insertion Depth ◽  
Lower Extent ◽  
Uncommon Complication

Migration of a cochlear implant electrode is a hitherto uncommon complication. So far, array migration has only been observed in lateral wall electrodes. Between 1999 and 2014, a total of 27 patients received bilateral perimodiolar electrode arrays at our institution. The insertion depth angle was estimated on the initial postoperative scans and compared with the insertion depth angle of the postoperative scans performed after contralateral cochlear implantation. Seven (25.93%) patients were found to have an electrode array migration of more than 15°. Electrode migration in perimodiolar electrodes seems to be less frequent and to occur to a lower extent than in lateral wall electrodes. Electrode migration was clinically asymptomatic in all cases.

scholarly journals The effect of increased channel interaction on speech perception with cochlear implants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tobias Goehring ◽  
Alan W. Archer-Boyd ◽  
Julie G. Arenberg ◽  
Robert P. Carlyon
Keyword(s):  
Speech Perception ◽  
Cochlear Implants ◽  
Causal Effect ◽  
Interaction Effects ◽  
Experimental Manipulation ◽  
Future Research ◽  
Specific Information ◽  
Electrode Arrays ◽  
Profound Hearing Loss ◽  
Channel Interaction

AbstractCochlear implants (CIs) are neuroprostheses that partially restore hearing for people with severe-to-profound hearing loss. While CIs can provide good speech perception in quiet listening situations for many, they fail to do so in environments with interfering sounds for most listeners. Previous research suggests that this is due to detrimental interaction effects between CI electrode channels, limiting their function to convey frequency-specific information, but evidence is still scarce. In this study, an experimental manipulation called spectral blurring was used to increase channel interaction in CI listeners using Advanced Bionics devices with HiFocus 1J and MS electrode arrays to directly investigate its causal effect on speech perception. Instead of using a single electrode per channel as in standard CI processing, spectral blurring used up to 6 electrodes per channel simultaneously to increase the overlap between adjacent frequency channels as would occur in cases with severe channel interaction. Results demonstrated that this manipulation significantly degraded CI speech perception in quiet by 15% and speech reception thresholds in babble noise by 5 dB when all channels were blurred by a factor of 6. Importantly, when channel interaction was increased just on a subset of electrodes, speech scores were mostly unaffected and were only significantly degraded when the 5 most apical channels were blurred. These apical channels convey information up to 1 kHz at the apical end of the electrode array and are typically located at angular insertion depths of about 250 up to 500°. These results confirm and extend earlier findings indicating that CI speech perception may not benefit from deactivating individual channels along the array and that efforts should instead be directed towards reducing channel interaction per se and in particular for the most-apical electrodes. Hereby, causal methods such as spectral blurring could be used in future research to control channel interaction effects within listeners for evaluating compensation strategies.

scholarly journals The Effect of Reducing the Number of Electrodes on Spatial Hearing Tasks for Bilateral Cochlear Implant Recipients

2010 ◽  
Vol 21 (02) ◽  
pp. 110-120 ◽  
Author(s):  
Ann Perreau ◽  
Richard S. Tyler ◽  
Shelley A. Witt
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Spatial Hearing ◽  
Electrode Arrays ◽  
Maximum Performance ◽  
Speech Perception In Noise ◽  
Spectral Bands ◽  
Maximal Performance ◽  
Bilateral Cochlear Implant

Background: Many studies have documented the effect of reducing spectral information for speech perception in listeners with normal hearing and hearing impairment. While it is understood that more spectral bands are needed for unilateral cochlear implant listeners to perform well on more challenging listening tasks such as speech perception in noise, it is unclear how reducing the number of spectral bands or electrodes in cochlear implants influences the ability to localize sound or understand speech with spatially separate noise sources. Purpose: The purpose of this study was to measure the effect of reducing the number of electrodes for patients with bilateral cochlear implants on spatial hearing tasks. Research Design: Performance on spatial hearing tasks was examined as the number of bilateral electrodes in the speech processor was deactivated equally across ears and the full frequency spectrum was reallocated to a reduced number of active electrodes. Program parameters (i.e., pulse width, stimulation rate) were held constant among the programs and set identically between the right and left cochlear implants so that only the number of electrodes varied. Study Sample: Nine subjects had used bilateral Nucleus or Advanced Bionics cochlear implants for at least 12 mo prior to beginning the study. Only those subjects with full insertion of the electrode arrays with all electrodes active in both ears were eligible to participate. Data Collection and Analysis: Two test measures were utilized to evaluate the effect of reducing the number of electrodes, including a speech-perception-in-noise test with spatially separated sources and a sound source localization test. Results: Reducing the number of electrodes had different effects across individuals. Three patterns emerged: (1) no effect on localization (two of nine subjects), (2) at least two to four bilateral electrodes were required for maximal performance (five of nine subjects), and (3) performance gradually decreased across conditions as electrode number was reduced (two of nine subjects). For the test of speech perception in spatially separated noise, performance was affected as the number of electrodes was reduced for all subjects. Two categories of performance were found: (1) at least three or four bilateral electrodes were needed for maximum performance (five of seven subjects) and (2) as the number of electrodes were reduced, performance gradually decreased across conditions (two of seven subjects). Conclusion: Large individual differences exist in determining maximum performance using bilateral electrodes for localization and speech perception in noise. For some bilateral cochlear implant users, as few as three to four electrodes can be used to obtain maximal performance on localization and speech-in-noise tests. However, other listeners show a gradual decrement in performance on both tasks when the number of electrodes is reduced.

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