Cochlear (France)

Objective Neurophysiologic measures like the electrically evoked Stapedius Reflex Threshold (eSRT) offer valuable insights into personalized responses to Cochlear Implant (CI) stimuli. This study evaluates the effects of stimulation current amplitude and the number of stimulating electrodes on eSRT and its correlation with the Most Comfortable Loudness level (MCL or C-level) in all-polar, pseudo-monophasic, pulse-width loudness coded stimulations. Approach The study was conducted on seventeen adult patients with Oticon Medical implants. In these implants, current amplitude remains constant while loudness is coded through pulse-width. Stimulation amplitudes were set to low (default clinical) and high values, using single or multi electrode groups of 1, 3, and 5 (G1, G3, and G5) across five cochlear regions, spanning from apical to basal. For each amplitude and group, the eSRT detection rate and correlation with MCL were analyzed regionally and overall. Results Higher eSRT detection rates were observed in the contra-lateral ear, with G3 and G5 significantly enhancing detection over G1 for both low and high amplitudes. The current amplitude facilitated eSRT invocation, particularly for G1 and patients with higher MCLs. The correlation between eSRT and MCL was relatively high (r = 0.64–0.87) across all conditions, indicating accurate MCL estimation from eSRT at both low and high amplitudes. Discussions Among all condition interactions (amplitude, side, electrodes), low-amplitude contra-lateral G5 and high-amplitude contra-lateral G3 showed optimal modes for estimating MCL from eSRT, with linear slopes near 1.0, and detection rates of 54% and 63%, respectively. High-amplitude contra-lateral G5 further increased detection to 68%, though with a slope of 0.8, requiring a correction factor. These findings provide insights into eSRT mechanisms and its application in pseudo-monophasic all-polar CI programming. Conclusion The eSRT detection rate can be improved in pulse-width modulation cochlear implants by using multi-electrode stimulation and/or increasing the stimulation amplitude beyond the default clinical value, without significantly affecting the correlation coefficient between eSRT and MCL.

Untreated hearing loss has an effect on cognition. It is hypothesized that the additional processing required to compensate for the sensory loss affects the cognitive resources available for other tasks and that this could be mitigated by a hearing device. The impact on cognition of cochlear implants (CIs) was tested in 100 subjects, ≥60 years old, with bilateral moderately-severe to profound post linguistic deafness using hearing aids. Data was compared pre and 12 and 18 months after cochlear implantation for the speech spatial qualities questionnaire, Mini Mental State Examination (MMSE), Trail making test B (TMTB) and digit symbol coding (DSC) from the Wechsler Adult Intelligence Scale version IV and finally the timed up and go test (TUG). Subjects were divided into young old (60-64), middle old (65-75) and old old (75+) groups. Cognitive test scores and times were standardized according to available normative data. Hearing significantly improved pre- to post-operatively across all age groups. There was no change post-implant in outcomes for TMTB, TUG or MMSE tests. Age-corrected values were within normal expectations for all age groups for the TUG and MMSE. However, DSC scores and TMTB times were worse than normal. There was a significant increase in DSC scores between baseline and 12-months for 60- to 64-year-olds (t[153] = 2.608, p = 0.027), which remained at 18 months (t[153] = 2.663, p = 0.023). The improved attention and processing speed in the youngest age group may be a consequence of reallocation of cognitive resources away from auditory processing due to greatly improved hearing. The oldest age group of participants had cognition scores closest to normal values, suggesting that only the most able older seniors tend to come forward for a CI. Severe to profoundly deaf individuals with hearing aids or cochlear implants were still poorer than age-equivalent normally hearing individuals with respect to cognitive flexibility, attention, working memory, processing speed and visuoperceptual functions. Due to a lack of data for the TUG, TMTB and DSC in the literature for hearing impaired individuals, the results reported here provide an important set of reference data for use in future research.

Adult cochlear implant (CI) recipients obtain varying levels of speech perception from their device. Adult CI users adapt quickly to their CI if they have no peripheral "bottom-up" or neurocognitive "top-down" limiting factors. Our objective here was to understand the influence of limiting factors on the progression of sentence understanding in quiet and in noise, initially and over time. We hypothesized that the presence of limiting factors, detected using a short test battery, would predictably influence sentence recognition with practical consequences. We aimed to validate the test battery by comparing the presence of limiting factors and the success criteria of >90% sentence understanding in quiet 1 month after activation. The study was a single-clinic, cross-sectional, retrospective design incorporating 32 adult unilateral Nucleus CI users aged 27 to 90 years (mean = 70, SD = 13.5). Postoperative outcome was assessed through sentence recognition scores in quiet and in varying signal to noise ratios at 1 day, 1 to 2 months, and up to 2 years. Our clinic's standard test battery comprises physiological and neurocognitive measures. Physiological measures included electrically evoked compound action potentials for recovery function, spread of excitation, and polarity effect. To evaluate general cognitive function, inhibition, and phonological awareness, the Montreal Cognitive Assessment screening test, the Stroop Color-Word Test, and tests 3 and 4 of the French Assessment of Reading Skills in Adults over 16 years of age, respectively were performed. Physiological scores were considered abnormal, and therefore limiting, when total neural recovery periods and polarity effects, for both apical and basal electrode positions, were >1.65 SDs from the population mean. A spread of excitation of >6 electrode units was also considered limiting. For the neurocognitive tests, scores poorer than 1.65 SDs from published normal population means were considered limiting. At 1 month, 13 out of 32 CI users scored ≥90% sentence recognition in quiet with no significant dependence on age. Subjects with no limiting peripheral or neurocognitive factors were 8.5 times more likely to achieve ≥90% score in quiet at 1 month after CI switch-on ( p = 0.010). In our sample, we detected 4 out of 32 cases with peripheral limiting factors that related to neural health or poor electrode-neural interface at both apical and basal positions. In contrast, neurocognitive limiting factors were identified in 14 out of 32 subjects. Early sentence recognition scores were predictive of long-term sentence recognition thresholds in noise such that limiting factors appeared to be of continuous influence. Both peripheral and neurocognitive processing factors affect early sentence recognition after CI activation. Peripheral limiting factors may have been detected less often than neurocognitive limiting factors because they were defined using sample-based criteria versus normal population-based criteria. Early performance was generally predictive of long-term performance. Understanding the measurable covariables that limit CI performance may inform follow-up and improve counseling. A score of ≥90% for sentence recognition in quiet at 1 month may be used to define successful progress; whereas, lower scores indicate the need for diagnostic testing and ongoing rehabilitation. Our findings suggest that sentence test scores as early as 1 day after activation can provide vital information for the new CI user and indicate the need for rehabilitation follow-up.

In this study, we proposed a novel semi-supervised training method that uses unlabeled data with a class distribution that is completely different from the target data or data without a target label. To this end, we introduce a contrastive regularization that is designed to be target task-oriented and trained simultaneously. In addition, we propose an audio mixing based simple augmentation strategy that performed in batch samples. Experimental results validate that the proposed method successfully contributed to the performance improvement, and particularly showed that it has advantages in stable training and generalization.

Objective:Evaluation of a new active osseointegrated bone-conduction hearing implant in moderate to severe mixed-hearing loss.Study Design:Prospective observational study of a series of cases.Setting:Tertial referral center.Patients:Twenty patients with moderate mixed-hearing loss were evaluated (10 Cochlear Osia group and 10 Baha 5 Power Connect -control group).Intervention:Rehabilitative.Main Outcome Measures:Hearing performance in quiet and in noise and quality-of-life were evaluated.Results:Improvements in audibility, speech-understanding, speech-recognition, and quality-of-sound in noise and quiet were found for the Osia System compared with preoperative unaided hearing and performance was similar to that obtained with Baha 5 Power Connect.Conclusions:The new active transcutaneous bone conduction system provided a tonal improvement in free-field at middle and high frequencies. The performance in speech recognition in quiet and in noise was similar to control group outcomes.

To assess the speech perception outcomes of adult CI recipients with significant preimplant low frequency hearing, examining differences between perimodiolar and lateral wall electrode placement in order to provide clinical guidance for clinicians and surgeons. A prospective cohort study was undertaken identifying all adults who received a thin straight electrode array (TSEA) at the Royal Victorian Eye & Ear Hospital (RVEEH) from 2010 to 2015 and who had a preimplant low frequency pure tone median ≤70 dB HL (n = 63). A retrospective review was completed of the RVEEH database to identify a comparison group who had been implanted with a perimodiolar electrode array, comprising adults implanted between 2004 and 2011 (PM Group) with preimplant hearing equivalent to the TSEA group (n = 70). The TSEA Group were further divided into subgroups in which n = 19 used EAS (TSEA-EAS) and n = 44 who used electric-only hearing (TSEA-Standard). There was no significant difference in median speech perception outcomes between the TSEA and PM Groups (TSEA 61.7%, PM 67.3%, p = 0.954). A significant difference was found between the TSEA-EAS and TSEA-Standard subgroups for median speech perception outcome (TSEA-EAS median 73.5%, TSEA-Standard median 58.3%, p = 0.043). Significant speech perception benefit following cochlear implantation was achieved with both the perimodiolar and lateral wall electrode arrays and no significant difference was found between outcomes with those array types in this population of adults with functional low frequency hearing pre-implant. Those that received a TSEA, had preserved hearing, and utilised an EAS sound processor performed better than their peers with a TSEA and electric-only hearing.

The aim of this study is to define an automated and reproducible framework for cochlear anatomical analysis from high-resolution segmented images and to provide a comprehensive and objective shape variability study suitable for cochlear implant design and surgery planning. For the scala tympani (ST), the scala vestibuli (SV) and the whole cochlea, the variability of the arc lengths and the radial and longitudinal components of the lateral, central and modiolar paths are studied. The robustness of the automated cochlear coordinate system estimation is validated with synthetic and real data. Cochlear cross-sections are statistically analyzed using area, height and width measurements. The cross-section tilt angle is objectively measured and this data documents a significant feature for occurrence of surgical trauma.

To determine if children with unilateral sensorineural hearing loss (UHL) demonstrate impaired balance compared with their normal hearing (NH) peers. Prospective, case-control study. Balance was assessed in14 UHL and 14 NH children using the Bruininks-Oseretsky Test-2 (BOT-2) and time to fall (TTF) in an immersive, virtual-reality laboratory. Postural control was quantified by center of pressure (COP) using force plates. The effect of vision on balance was assessed by comparing scores and COP characteristics on BOT-2 tasks performed with eyes open and closed. Balance ability as measured by the BOT-2 score was significantly worse in children with UHL compared with NH children (p = 0.004). TTF was shorter in children with UHL compared with NH children in the most difficult tasks when visual and somatosensory inputs were limited (p < 0.01). Visual input improved postural control (reduced COP variability) in both groups in all tasks (p < 0.05) but postural control as measured by COP variability was more affected in children with UHL when visual input was removed while performing moderately difficult tasks (i.e., standing on one foot) (p = 0.02). In this pilot study, children with UHL show poorer balance skills than NH children. Significant differences in TTF between the two groups were only seen in the most difficult tasks and therefore may be missed on routine clinical assessment. Children with UHL appear to rely more on vision for maintaining postural control than their NH peers. These findings may point to deficits not only in the hearing but also the vestibular portion of the inner ear.

Musical enjoyment for cochlear implant (CI) recipients is often reported to be unsatisfactory. Our goal was to determine whether the musical experience of postlingually deafened adult CI recipients could be enriched by presenting the bass and treble clef parts of short polyphonic piano pieces separately to each ear (dichotic). Dichotic presentation should artificially enhance the lateralization cues of each part and help the listeners to better segregate them and thus provide greater clarity. We also hypothesized that perception of the intended emotion of the pieces and their overall enjoyment would be enhanced in the dichotic mode compared with the monophonic (both parts in the same ear) and the diotic mode (both parts in both ears). Twenty-eight piano pieces specifically composed to induce sad or happy emotions were selected. The tempo of the pieces, which ranged from lento to presto covaried with the intended emotion (from sad to happy). Thirty participants (11 normal-hearing listeners, 11 bimodal CI and hearing-aid users, and 8 bilaterally implanted CI users) participated in this study. Participants were asked to rate the perceived clarity, the intended emotion, and their preference of each piece in different listening modes. Results indicated that dichotic presentation produced small significant improvements in subjective ratings based on perceived clarity. We also found that preference and clarity ratings were significantly higher for pieces with fast tempi compared with slow tempi. However, no significant differences between diotic and dichotic presentation were found for the participants’ preference ratings, or their judgments of intended emotion.