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Objective: The purpose of this study was to compare the originally applied frequency allocation of cochlear implant electrodes assigned by default at the time of activation with a more recent frequency allocation that is anatomy-based by a software called OTOPLAN®. Based on a computed tomography scan of the temporal bone, this software calculates the position of each electrode in the cochlea and its corresponding tonotopic frequency. We also evaluated whether patients with a significant mismatch between these two allocations present poorer speech intelligibility. Materials and Methods: Patients who underwent cochlear implantation from 2016 to 2021 at the University Hospital of Liege were included in this retrospective study. We used OTOPLAN® to calculate the tonotopic frequency allocation of each electrode according to its exact position in the cochlear duct. This anatomical frequency mapping was compared with the default frequency mapping at the time of cochlear implant activation. Finally, we compared the mismatch with the patients' auditory performance, represented by the Auditory Capacity Index (ACI). Results: Thirteen patients were included in the study. All patients had a mismatch between the two frequency maps, to a variable extent (200 Hz–1,100 Hz). Frequency shift was significantly inversely correlated with ACI and with the time needed to improve speech intelligibility. Conclusion: Our primary results show that patients with a larger mismatch between default frequency mapping and anatomically assigned frequency mapping experience poorer hearing performance and slower adaptation to a cochlear implant. [ABSTRACT FROM AUTHOR]

Abstract Background The standard electrode array for the MED-EL MAESTRO cochlear implant system is 31 mm in length which allows an insertion angle of approximately 720°. When fully inserted, this long electrode array is capable of stimulating the most apical region of the cochlea. No investigation has explored Electrically Evoked Compound Action Potential (ECAP) recordings in this region with a large number of subjects using a commercially available cochlear implant system. The aim of this study is to determine if certain properties of ECAP recordings vary, depending on the stimulation site in the cochlea. Methods Recordings of auditory nerve responses were conducted in 67 subjects to demonstrate the feasibility of ECAP recordings using the Auditory Nerve Response Telemetry (ART™) feature of the MED-EL MAESTRO system software. These recordings were then analyzed based on the site of cochlear stimulation defined as basal, middle and apical to determine if the amplitude, threshold and slope of the amplitude growth function and the refractory time differs depending on the region of stimulation. Results Findings show significant differences in the ECAP recordings depending on the stimulation site. Comparing the apical with the basal region, on average higher amplitudes, lower thresholds and steeper slopes of the amplitude growth function have been observed. The refractory time shows an overall dependence on cochlear region; however post-hoc tests showed no significant effect between individual regions. Conclusions Obtaining ECAP recordings is also possible in the most apical region of the cochlea. However, differences can be observed depending on the region of the cochlea stimulated. Specifically, significant higher ECAP amplitude, lower thresholds and steeper amplitude growth function slopes have been observed in the apical region. These differences could be explained by the location of the stimulating electrode with respect to the neural tissue in the cochlea, a higher density, or an increased neural survival rate of neural tissue in the apex. Trial registration The Clinical Investigation has the Competent Authority registration number DE/CA126/AP4/3332/18/05.

Objectives: Speech understanding in noise remains a challenge for many cochlear implant users. To improve this, the SONNET audio processor features three microphone directionality (MD) settings and three wind noise reduction (WNR) settings. The primary aim of this study was to assess if speech understanding in noise and hearing in real life was superior with the SONNET or with the OPUS 2, which does not feature MD or WNR.Methods: 31 of 33 participants completed the study. Speech understanding was assessed in two types of acoustic noise, in wind noise, and in quiet. A 4-speaker setup was used and speech was presented from 0° and noise from 90°, 180°, and 270°. Wind noise was simulated with a fan. Sound quality and hearing-related abilities were assessed via two subjective questionnaires.Results: Speech understanding in acoustic noise with the SONNET was significantly better or equal to than with the OPUS 2. Speech understanding in wind with the OPUS 2 was significantly better than with the SONNET in some settings. Sound quality and hearing-related abilities were both significantly better with the SONNET.Conclusions: The SONNET provides the same or significantly improved speech understanding than the OPUS 2 in quiet and in noise. While OPUS 2 was superior in wind than the SONNET in some settings, this was offset by SONNET's superiority in real-life listening situations. We therefore conclude that the front-end processing of the SONNET provides users with better hearing than does the OPUS 2. [ABSTRACT FROM AUTHOR]

The article reports on the incapacitating unilateral tinnitus in single-sided deafness which was treated by cochlear implantation. It discusses that tinnitus is a well-known, hard-to-treat symptom of hearing loss. It discusses that the users of cochlear implants (CIs) have described a reduction in tinnitus following implantation for bilateral severe-to-profound deafness.

AbstractObjectiveDesignStudy sampleResultsConclusionsOne proposed method to improve sound localisation for bilateral cochlear implant (BiCI) users is to synchronise the automatic gain control (AGC) of both audio processors. In this study we tested whether AGC synchronisation in a dual-loop front-end processing scheme with a 3:1 compression ratio improves sound localisation acuity.Source identification in the frontal hemifield was tested in in an anechoic chamber as a function of (roving) presentation level. Three different methods of AGC synchronisation were compared to the standard unsynchronised approach. Both root mean square error (RMSE) and signed bias were calculated to evaluate sound localisation in the horizontal plane.Six BiCI users.None of the three AGC synchronisation methods yielded significant improvements in either localisation error or bias, neither across presentation levels nor for individual presentation levels. For synchronised AGC, the pooled mean (standard deviation) localisation error of the three synchronisation methods was 24.7 (5.8) degrees RMSE, for unsynchronised AGC it was 27.4 (7.5) degrees. The localisation bias was 5.1 (5.5) degrees for synchronised AGC and 5.0 (3.8) for unsynchronised.These findings do not support the hypothesis that the tested AGC synchronisation configurations improves localisation acuity in bilateral users of MED-EL cochlear implants. [ABSTRACT FROM AUTHOR]