An Environment‐Adaptive Management Algorithm for Hearing‐Support Devices Incorporating Listening Situation and Noise Type Classifiers

In order to provide more consistent sound intelligibility for the hearing‐impaired person, regardless of environment, it is necessary to adjust the setting of the hearing‐support (HS) device to accommodate various environmental circumstances. In this study, a fully automatic HS device management algorithm that can adapt to various environmental situations is proposed; it is composed of a listening‐situation classifier, a noise‐type classifier, an adaptive noise‐reduction algorithm, and a management algorithm that can selectively turn on/off one or more of the three basic algorithms—beamforming, noise‐reduction, and feedback cancellation—and can also adjust internal gains and parameters of the wide‐dynamic‐range compression (WDRC) and noise‐reduction (NR) algorithms in accordance with variations in environmental situations. Experimental results demonstrated that the implemented algorithms can classify both listening situation and ambient noise type situations with high accuracies (92.8–96.4% and 90.9–99.4%, respectively), and the gains and parameters of the WDRC and NR algorithms were successfully adjusted according to variations in environmental situation. The average values of signal‐to‐noise ratio (SNR), frequency‐weighted segmental SNR, Perceptual Evaluation of Speech Quality, and mean opinion test scores of 10 normal‐hearing volunteers of the adaptive multiband spectral subtraction (MBSS) algorithm were improved by 1.74 dB, 2.11 dB, 0.49, and 0.68, respectively, compared to the conventional fixed‐parameter MBSS algorithm. These results indicate that the proposed environment‐adaptive management algorithm can be applied to HS devices to improve sound intelligibility for hearing‐impaired individuals in various acoustic environments.     

A Diagonal‐Steering‐Based Binaural Beamforming Algorithm Incorporating a Diagonal Speech Localizer for Persons With Bilateral Hearing Impairment

Previously suggested diagonal‐steering algorithms for binaural hearing support devices have commonly assumed that the direction of the speech signal is known in advance, which is not always the case in many real circumstances. In this study, a new diagonal‐steering‐based binaural speech localization (BSL) algorithm is proposed, and the performances of the BSL algorithm and the binaural beamforming algorithm, which integrates the BSL and diagonal‐steering algorithms, were evaluated using actual speech‐in‐noise signals in several simulated listening scenarios. Testing sounds were recorded in a KEMAR mannequin setup and two objective indices, improvements in signal‐to‐noise ratio (SNR_i) and segmental SNR (segSNR_i), were utilized for performance evaluation. Experimental results demonstrated that the accuracy of the BSL was in the 90–100% range when input SNR was ?10 to +5 dB range. The average differences between the γ‐adjusted and γ‐fixed diagonal‐steering algorithms (for ?15 to +5 dB input SNR) in the talking in the restaurant scenario were 0.203–0.937 dB for SNR_i and 0.052–0.437 dB for segSNR_i, and in the listening while car driving scenario, the differences were 0.387–0.835 dB for SNR_i and 0.259–1.175 dB for segSNR_i. In addition, the average difference between the BSL‐turned‐on and the BSL‐turned‐off cases for the binaural beamforming algorithm in the listening while car driving scenario was 1.631–4.246 dB for SNR_i and 0.574–2.784 dB for segSNR_i. In all testing conditions, the γ‐adjusted diagonal‐steering and BSL algorithm improved the values of the indices more than the conventional algorithms. The binaural beamforming algorithm, which integrates the proposed BSL and diagonal‐steering algorithm, is expected to improve the performance of the binaural hearing support devices in noisy situations.     

An Eye‐Blinking‐Based Beamforming Control Protocol for Hearing Aid Users With Neurological Motor Disease or Limb Amputation

For hearing‐impaired individuals with neurological motor deficits or finger/arm amputation due to accident or disease, hearing aid adjustment using a conventional finger manipulation‐based remote controller is unavailable, and a more dedicated, hands‐free alternative is required. In this study, we propose an eye‐blinking‐based beamforming control scheme for hearing aid users. Three electroencephalogram signals measured around the ears were utilized to detect eye‐blinking patterns based on a three‐layer artificial neural network. The performance of the proposed control scheme was evaluated by both subjective experiments and objective index comparison tests in simulated situations. Experimental results from the subjective test demonstrated that without the pretraining phase, the accuracy and latency time were 68.57 ± 18.50% and 10.06 ± 0.94 s, respectively; in contrast, after the pretraining phase, both the accuracy and latency time were improved to 91.00 ± 4.69% and 8.60 ± 1.05 s, respectively. In index comparison tests, the proposed control scheme exhibited improvements in the signal‐to‐noise ratio (SNR) as well as the segmental SNR in all tested situations, as compared to a conventional forward‐focusing beamforming algorithm. We believe that the proposed control scheme provides a novel, hands‐free way in which to control the operation of hearing aids for hearing‐impaired patients with additional motor deficits or amputation.     

Meniscal repair with the MaxFire device: a cadaveric study

Objective: To use a cadaver model to evaluate an all‐inside meniscal repair device (MaxFire). Methods: Six fresh‐frozen cadaveric knees (ages 30–84 years) without evidence of prior surgery were used for this study. The knees were rigidly mounted and arthroscopy performed using standard anteromedial and anterolateral portals. Four MaxFire devices were placed into the medial and lateral meniscus according to the technique provided by the manufacturer. The devices were placed in a vertical or horizontal mattress fashion systematically from posterior to anterior. Implants were placed from either the ipsilateral‐ or contralateral‐portal at the discretion of each surgeon. Placement into the medial meniscus was performed with the knee in approximately 10° of flexion and into the lateral meniscus in 45° of flexion. Results: In all, 54 MaxFire devices were placed. Twenty‐six devices were used medially, and 28 laterally. Forty‐five (83%) were placed successfully. Of those, 3 (7%) were placed in a “top hat” fashion. The nine failures (17%) were related to final device tensioning. Three of the sutures broke, one suture would not reduce, and three implants pulled out of the meniscus. The devices were successfully removed arthroscopically with a grasper or oscillating shaver. Pulling of implants out of menisci occurred in degenerative knees with degenerative meniscal tissue and did not occur with healthy appearing menisci. Conclusion: The MaxFire device is easy to use, has a low risk of complications, and can be inserted expeditiously by arthroscopy.     

Comparison of speech perception abilities in deaf children with hearing aids or cochlear implants

The speech perception abilities of deaf children with a single- or multi-channel cochlear implant are compared with those of deaf children who derive substantial benefit from conventional hearing aids. The children with hearing aids have unaided pure-tone thresholds ranging from 90- to 110-dB HL through at least 2000 Hz, and aided thresholds of 30- to 60-dB HL. The group data show that the speech perception scores of the subjects with hearing aids were significantly higher than those of the subjects with implants on a range of speech perception measures. Although a few subjects with implants achieved scores as high as those who used hearing aids, the majority did not. Even though the children with implants receive substantial benefit from their devices, they continue to have limited auditory perception abilities relative to their peers who derive benefit from conventional hearing aids. The data highlight the importance of establishing hearing aid benefit in potential candidates for implant.     

In Vitro Evaluation of the Dual‐Diffuser Design for a Reversible Rotary Intra‐Aortic Ventricular Assist Device

The intra‐aortic ventricular assist device (IntraVAD) is a miniature intra‐aortic axial‐flow ventricular assist device (VAD) that works in series with the left ventricle (LV) to assist the compromised heart. Previous in vitro results have shown that the IntraVAD can successfully increase coronary perfusion and offload ventricular volume by operating in reverse‐rotation control (RRc) mode. The RRc mode includes forward rotation in systole and reverse rotation (RR) in diastole. It is necessary to derive a new diffuser design that can be used for the bi‐directional rotation of the IntraVAD. In this work, a dual‐diffuser set (DDS) was proposed to replace the conventional inducer and diffuser upstream and downstream of the pump. The DDS comprised two diffusers, located on both sides of the impeller, omitting the conventional inducer and diffuser. Different configurations of the DDS were designed and manufactured with various combinations of curved and straight blades. All configurations were initially tested in continuous flow, then in a pulsatile mock circulatory loop. A weighted normalized scalar (WNS) was proposed to comprehensively evaluate the hemodynamic effect of the DDS with different configurations. The results show that the maximum of WNS occurred when the upstream diffuser had equal numbers of curved and straight blades and the downstream diffuser had only curved blades. This indicates such a dual‐diffuser design for the IntraVAD can give an optimal cardiac assistance potentially improving ventricular contractility, thereby restoring heart function.     

The conventional hearing aid

The conventional hearing aid has benefited from the progress made in electronic miniaturization and digital signal processing. The prescriber should be familiar with these improvements, the anatomic and acoustic limitations related to hearing aids, the possibilities of surgical rehabilitation, as well as the indications for other auditive rehabilitation techniques (bone conduction hearing, middle ear implant, and cochlear implant). A hearing aid should be prescribed within a precise context taking into account patient history, clinical examination, audiometric testing, and choice of the device. Optimal management of a hearing device for a child should be conducted within an adapted network including a specialized ENT physician, audiophonology, a qualified hearing prosthetist, a speech therapist, etc.).     

A speech-to-noise ratio test with the bone-anchored hearing aid: a comparative study

Hitherto, for persons with impaired hearing who cannot use an air conduction hearing aid, the only alternative has been a conventional spring-loaded bone conduction hearing aid. Now, with minor surgery, a titanium screw can be implanted in the bone behind the ear and a coupling, which penetrates the skin, can be attached, giving a new kind of hearing aid--the "bone-anchored hearing aid." Improved quality of sound is one of the patients' subjective assessments. Improvement was not confirmed by a standard speech-discrimination test. With new speech material consisting of sentences in noise, the speech-to-noise ration (SN) has been determined for 24 patients. Patients who previously used a conventional bone conduction hearing aid improved their SN on the average by 3.3 dB. The most important difference between the two aids related to improved SN is probably the increased audibility between 600 and 6000 Hz.     

The effects of age on auditory speech perception development in cochlear-implanted prelingually deaf children.

One of the most important factors in auditory speech perception of cochlear-implanted children is age. The goal of this study was to compare auditory speech perception among children implanted from 6 different age groups: 0 to 3, 4 to 5, 6 to 7, 8 to 9, 10 to 11, and >12 years. The subjects of this study were matched based on socioeconomic status, residual hearing before cochlear implantation, the kinds of cochlear implant device, speech processing strategy, communication mode after implantation, and primary language in family. All of them have used the device minimally for 2 years. The subjects were tested with a range of closed and open-set auditory speech perception tests, and the levels of auditory speech perception in different age groups were compared. Results showed that the children who received an implant at 0 to 3 years of age had maximum auditory speech perception.     

Evidence of left inferior frontal-premotor structural and functional connectivity deficits in adults who stutter

The neurophysiological basis for stuttering may involve deficits that affect dynamic interactions among neural structures supporting fluid speech processing. Here, we examined functional and structural connectivity within corticocortical and thalamocortical loops in adults who stutter. For functional connectivity, we placed seeds in the left and right inferior frontal Brodmann area 44 (BA44) and in the ventral lateral nucleus (VLN) of the thalamus. Subject-specific seeds were based on peak activation voxels captured during speech and nonspeech tasks using functional magnetic resonance imaging. Psychophysiological interaction (PPI) was used to find brain regions with heightened functional connectivity with these cortical and subcortical seeds during speech and nonspeech tasks. Probabilistic tractography was used to track white matter tracts in each hemisphere using the same seeds. Both PPI and tractrography supported connectivity deficits between the left BA44 and the left premotor regions, while connectivity among homologous right hemisphere structures was significantly increased in the stuttering group. No functional connectivity differences between BA44 and auditory regions were found between groups. The functional connectivity results derived from the VLN seeds were less definitive and were not supported by the tractography results. Our data provide strongest support for deficient left hemisphere inferior frontal to premotor connectivity as a neural correlate of stuttering.     

Improvement of chronic hearing loss after shunt revision. A case report

BACKGROUND: Hearing loss after intracranial and spinal procedures involving cerebrospinal fluid loss is rarely reported in the literature. We report a patient who suffered from delayed hearing loss after cerebrospinal fluid shunting that improved after revising the shunt to a higher-pressure valve. CASE DESCRIPTION: A 32-year-old woman presented with bilateral hearing loss 4 years after ventriculoperitoneal shunting for communicating hydrocephalus. Her otologic work-up revealed sensorineural hearing loss. In an attempt to improve her hearing, 6 years after the hearing loss began (10 years after the shunt was placed), she underwent a shunt revision in which her valve was changed to a higher-pressure device. After the procedure, she had a significant improvement in her speech discrimination and a mild improvement in her pure tone recognition. These changes were documented with serial audiograms. CONCLUSION: Hearing loss after cerebrospinal shunting procedures is not always limited to the immediate postoperative period. It may be a late complication of cerebrospinal fluid diversion. Chronic hearing loss after ventriculoperitoneal shunting may be treatable by changing the valve to a higher-pressure device. The etiology of hearing loss from intracranial hypotension is briefly discussed.     

Microvascular Damage in Type 1 Diabetic Patients Is Reversed in the First Year After Simultaneous Pancreas–Kidney Transplantation

Simultaneous pancreas–kidney transplantation (SPK) is an advanced treatment option for type 1 diabetes mellitus (DM) patients with microvascular disease including nephropathy. Sidestreamdarkfield (SDF) imaging has emerged as a noninvasive tool to visualize the human microcirculation. This study assessed the effect of SPK in diabetic nephropathy (DN) patients on microvascular alterations using SDF and correlated this with markers for endothelial dysfunction. Microvascular morphology was visualized using SDF of the oral mucosa in DN (n = 26) and SPK patients (n = 38), healthy controls (n = 20), DM1 patients (n = 15, DM ≥ 40 mL/min) and DN patients with a kidney transplant (KTx, n = 15). Furthermore, 21 DN patients were studied longitudinally up to 12 months after SPK. Circulating levels of angiopoietin‐1 (Ang‐1), angiopoietin‐2 (Ang‐2) and soluble thrombomodulin (sTM) were measured using ELISA. Capillary tortuosity in the DN (1.83 ± 0.42) and DM ≥ 40 mL/min (1.55 ± 0.1) group was increased and showed reversal after SPK (1.31 ± 0.3, p < 0.001), but not after KTx (1.64 ± 0.1). sTM levels were increased in DN patients and reduced in SPK and KTx recipients (p < 0.05), while the Ang‐2/Ang‐1 ratio was normalized after SPK and not after KTx alone (from 0.16 ± 0.04 to 0.08 ± 0.02, p < 0.05). Interestingly, in the longitudinal study, reversal of capillary tortuosity and decrease in Ang‐2/Ang‐1 ratio and sTM was observed within 12 months after SPK. SPK is effective in reversing the systemic microvascular structural abnormalities in DN patients in the first year after transplantation.     

Modified whale optimization algorithm for fractional‐order multi‐input SSSC‐based controller design

In this paper, the design of a fractional‐order (FO) multi‐input–single‐output (MISO)–type static synchronous series compensator (SSSC) is proposed with a goal to improve the power system stability using modified whale optimization algorithm (MWOA). The proposed MWOA achieves an appropriate balance between exploitation and exploration stages of the original whale optimization algorithm. The performance of MWOA is validated by employing the benchmark test functions and further contrasted with whale optimization algorithm and other heuristic algorithms like gravitational search algorithm, particle swarm optimization, differential evolution, and fast evolutionary programming algorithms to demonstrate its strength. The proposed FO MISO SSSC controller is optimized by the MWOA technique and tested under single‐machine infinite bus system and further extended to a multi‐machine framework. To demonstrate the superiority of MISO‐type SSSC controller, the results obtained from it are compared with particle swarm optimization and differential evolution–based conventional single‐input–single‐output structured SSSC controllers. The comparison of results of MWOA with that of other methods validates its superiority in the present context.     

An optimized fuzzy continuous sliding mode controller combined with an adaptive proportional-integral-derivative control for uncertain systems

This article discusses the design of a hybrid fuzzy variable structure control algorithm combined with genetic algorithm (GA) optimization technique to improve the adaptive proportional-integral-derivative (PID) continuous second-order sliding mode control approach (APID2SMC), recently published in our previous article in the literature. In this article, first, as an improved extension to APID2SMC published recently in the literature, an adaptive proportional-integral-derivative fuzzy sliding mode scheme (APIDFSMC) is presented in which a fuzzy logic controller is added. Second, a GA-based adaptive PID fuzzy sliding mode control approach (APIDFSMC-GA) is introduced to obtain the optimal control parameters of the fuzzy controller in APIDFSMC. The proposed control algorithms are derived based on Lyapunov stability criterion. Simulations results show that the proposed approaches provide robustness for trajectory tracking performance under the occurrence of uncertainties. These simulation results, compared with the results of conventional sliding mode controller, APID2SMC, and standalone classical PID controller, indicate that the proposed control methods yield superior and favorable tracking control performance over the other conventional controllers.     

微型系统22型人工耳蜗植入术的手术护理

微型系统２２型人工耳蜗植入术是世界目前治疗重度感音神经性耳聋比较理想的治疗方法。传送器与内置接受器通过磁性作用吸在耳后，可随意摘取，方便病人日常生活及体育活动。洋但可使病人听到声音，并且可以辨别环境中声音的种类，能提高病人对语言的理解能力。     

Phase 1 clinical trial results of the envoy system: A totally implantable middle ear device for sensorineural hearing loss

OBJECTIVES: This report will present the results of the USA Phase 1 clinical trials for the Envoy System (St. Croix Medical): A totally implantable middle ear hearing system for sensorineural loss. STUDY DESIGN: A prospective, single-subject, repeated-measures, multicenter study was performed to evaluate safety and functionality of the Envoy System. Data collected included Abbreviated Profile of Hearing Aid Benefit, bone conduction threshold, speech reception threshold, functional gain, word recognition, and adverse events. Testing was performed unaided, with the patient's best-fit hearing aid, and post device activation at 2 (trial endpoint) and 4 months. RESULTS: Five of 7 patients at the 2-month postactivation period had working systems. All 5 patients perceived benefit increases with the Envoy System over their best-fit hearing aid, including communication in high background noise levels. Word recognition was improved over hearing aids. Functional gain and speech reception thresholds were similar for the Envoy device and hearing aids. CONCLUSIONS: The feasibility trial has shown the Envoy device, a totally implantable middle ear device, can safely sense and drive the ossicular chain. EBM RATING: B-2.     

Stability analysis of an enhanced load sharing posterior fixation device and its equivalent conventional device in a calf spine model

STUDY DESIGN: An in vitro test of calf spine lumbar segments to compare biomechanical stabilization of a rigid versus a dynamic posterior fixation device. OBJECTIVES: To compare flexibility of a dynamic pedicle screw fixation device with an equivalent rigid device. SUMMARY OF BACKGROUND DATA: Dynamic pedicle screw device studies are not as prevalent in the literature as studies of rigid devices. These devices contain the potential to enhance load sharing and optimize fusion potential while maintaining stability similar to that of rigid systems. METHODS: Load-displacement tests were performed on intact and stabilized calf spines for the dynamic and rigid devices. Stability across a destabilized L3-L4 segment was restored by insertion of either a 6 mm x 40 mm dynamic or rigid pedicle screw fixation device across the L2-L4 segment. The screws then were removed, 7 mm x 45 mm pedicle screws of the opposite type were inserted, and the construct then was re-tested. Axial pull-out tests were performed to assess the likely effects of pedicle screw replacement on the load-displacement data. RESULTS: Results indicated a 65% reduction in motion in flexion-extension and a 90% reduction in lateral bending across the destabilized level for both devices, compared with intact spine values. Reduction in axial rotation motion was much smaller than in other modes. Axial pull-out tests showed no weakening of the bone-screw interface. CONCLUSIONS: Both devices provided significant stability of similar magnitudes in flexion, extension, and lateral bending. In axial rotation, the devices only could restore stability to levels similar to those in an intact spine. The dynamic device offers a design that may enhance load sharing without sacrificing construct stability.     

Interhemispheric differences in auditory processing revealed by fMRI in awake rhesus monkeys

Lesion studies in monkeys have suggested a modest left hemisphere dominance for processing species-specific vocalizations, the neural basis of which has thus far remained unclear. We used contrast agent-enhanced functional magnetic resonance imaging to map the regions of the rhesus monkey brain involved in processing conspecific vocalizations as well as human speech and emotional sounds. Control conditions included scrambled versions of all 3 stimuli and silence. Compared with silence, all stimuli activated widespread parts of the auditory cortex and subcortical auditory structures with a right hemispheric bias at the level of the auditory core. However, comparing intact with scrambled sounds revealed a leftward bias in the auditory belt and the parabelt. The left-sided dominance was stronger and more robust for human speech than for rhesus vocalizations and hence does not reflect conspecific call selectivity but rather the processing of complex spectrotemporal patterns, such as those present in human speech and in some of the rhesus monkey vocalizations. This was confirmed by regressing brain activity with a model-derived parameter indexing the prevalence of such patterns. Our results indicate that processing of vocal sounds in the lateral belt and parabelt is asymmetric in monkeys, as predicted from lesion studies.     

Phase III clinical trial results with the Vibrant Soundbridge implantable middle ear hearing device: a prospective controlled multicenter study.

OBJECTIVES: The goal of the study was to evaluate the performance of a semi-implantable middle ear hearing device (Vibrant Soundbridge System [VSB]; Symphonix Devices, Inc). STUDY DESIGN: A prospective, single-subject, repeated-measures multicenter study was conducted to determine the safety and efficacy of the VSB using analog and digital external processors. Measures included residual hearing, functional gain, speech recognition, acoustic feedback, occlusion, and patient self-assessment to determine satisfaction, perceived performance, and device preference compared with an appropriately fit acoustic hearing aid. Fifty-three adult subjects with moderate to severe sensorineural hearing loss were evaluated at 4 or more intervals after implantation. RESULTS: Improvements in satisfaction, performance, and preference were statistically significant with the VSB, as was functional gain across all test frequencies (P < 0.001). Occlusion and feedback were virtually eliminated. Aided speech recognition was comparable between VSB and the hearing aid. Residual hearing was unchanged. CONCLUSION: The VSB is a safe and effective treatment option for adults with moderate to severe sensorineural hearing loss.