Objective Binaural Loudness Balancing Based on 40-Hz Auditory Steady-State Responses. Part II: Asymmetric and Bimodal Hearing.

In Part I, we investigated 40-Hz auditory steady-state response (ASSR) amplitudes for the use of objective loudness balancing across the ears for normal-hearing participants and found median across-ear ratios in ASSR amplitudes close to 1. In this part, we further investigated whether the ASSR can be used to estimate binaural loudness balance for listeners with asymmetric hearing, for whom binaural loudness balancing is of particular interest. We tested participants with asymmetric hearing and participants with bimodal hearing, who hear with electrical stimulation through a cochlear implant (CI) in one ear and with acoustical stimulation in the other ear. Behavioral loudness balancing was performed at different percentages of the dynamic range. Acoustical carrier frequencies were 500, 1000, or 2000 Hz, and CI channels were stimulated in apical or middle regions in the cochlea. For both groups, the ASSR amplitudes at balanced loudness levels were similar for the two ears, with median ratios between left and right ear stimulation close to 1. However, individual variability was observed. For participants with asymmetric hearing loss, the difference between the behavioral balanced levels and the ASSR-predicted balanced levels was smaller than 10 dB in 50% and 56% of cases, for 500 Hz and 2000 Hz, respectively. For bimodal listeners, these percentages were 89% and 60%. Apical CI channels yielded significantly better results (median difference near 0 dB) than middle CI channels, which had a median difference of -7.25 dB.

Evaluation of Noise Reduction Algorithms in Hearing Aids for Multiple Signals From Equal or Different Directions.

One objective way to evaluate the effect of noise reduction algorithms in hearing aids is to measure the increase in signal-to-noise-ratio (SNR). To this end, Hagerman and Olofsson presented a method where multiple recordings take place and the phase of one signal is inverted between the measurements. This phase inversion method allows one to separate signal and noise at the output of the hearing aid so that the increase in SNR can be evaluated. However, only two signals can be distinguished, for example, speech and noise. As many realistic situations include more than two signals, we extend the method to an arbitrary number of signals. Two different approaches are discussed. For the first one, groups of the signals are created and presented in such a way that the basic phase inversion method can be used. The second, more efficient approach defines a linear system of equations considering all signals. As the robustness of this approach depends on the structure of the system matrix, the design of this matrix is described in detail. To prove the concept, the proposed efficient method was applied to a setup in which nine different signals were presented by eight loudspeakers, and an analysis of errors was performed. With this setup, a state-of-the-art hearing aid was analyzed for four different settings, that is, with the digital noise reduction or the directional microphones turned on or off. As a result, the SNRs for all directions can be investigated individually.

Patient Acceptance of Invasive Treatments for Tinnitus.

PURPOSE: The field of neuromodulation is currently seeking to treat a wide range of disorders with various types of invasive devices. In recent years, several preclinical trials and case reports in humans have been published on their potential for chronic tinnitus. However, studies to obtain insight into patients' willingness to undergo these treatments are scarce. The aim of this survey study was to find out whether tinnitus patients are willing to undergo invasive neuromodulation when taking its risks, costs, and potential benefits into account. METHOD: A Visual Analog Scale (VAS, 0-10) was used to measure the outcome. Spearman's rank-order correlation coefficients were computed to determine the correlation between patient characteristics and acceptance rates. RESULTS: Around one fifth of the patients were reasonably willing to undergo invasive treatment (VAS 5-7), and around one fifth were fully willing to do so (VAS 8-10). Hearing aids, used as a control, were accepted most, followed by cochlear implantation, deep brain stimulation, and cortical stimulation. Acceptance rates were slightly higher when the chance of cure was higher. Patients with a history of attempted treatments were more eager than others to find a new treatment for tinnitus. CONCLUSIONS: A considerable proportion of patients with tinnitus would accept a variety of invasive treatments despite the associated risks or costs. When clinical neuromodulatory studies for tinnitus are to be performed, particular attention should be given to obtaining informed consent, including explaining the potential risks and providing a realistic outcome expectation.

Clinical validation of a public health policy-making platform for hearing loss (EVOTION): protocol for a big data study.

INTRODUCTION: The holistic management of hearing loss (HL) requires an understanding of factors that predict hearing aid (HA) use and benefit beyond the acoustics of listening environments. Although several predictors have been identified, no study has explored the role of audiological, cognitive, behavioural and physiological data nor has any study collected real-time HA data. This study will collect 'big data', including retrospective HA logging data, prospective clinical data and real-time data via smart HAs, a mobile application and biosensors. The main objective is to enable the validation of the EVOTION platform as a public health policy-making tool for HL. METHODS AND ANALYSIS: This will be a big data international multicentre study consisting of retrospective and prospective data collection. Existing data from approximately 35 000 HA users will be extracted from clinical repositories in the UK and Denmark. For the prospective data collection, 1260 HA candidates will be recruited across four clinics in the UK and Greece. Participants will complete a battery of audiological and other assessments (measures of patient-reported HA benefit, mood, cognition, quality of life). Patients will be offered smart HAs and a mobile phone application and a subset will also be given wearable biosensors, to enable the collection of dynamic real-life HA usage data. Big data analytics will be used to detect correlations between contextualised HA usage and effectiveness, and different factors and comorbidities affecting HL, with a view to informing public health decision-making. ETHICS AND DISSEMINATION: Ethical approval was received from the London South East Research Ethics Committee (17/LO/0789), the Hippokrateion Hospital Ethics Committee (1847) and the Athens Medical Center's Ethics Committee (KM140670). Results will be disseminated through national and international events in Greece and the UK, scientific journals, newsletters, magazines and social media. Target audiences include HA users, clinicians, policy-makers and the general public. TRIAL REGISTRATION NUMBER: NCT03316287; Pre-results.

[Pre- and posttreatment results of an inpatient neurotologic and psychosomatic tinnitus therapy]. / Prä- und Post-Ergebnisse einer stationären neurootologisch fundierten und psychosomatischen Tinnitustherapie.

BACKGROUND: Inpatient treatment of chronic complex tinnitus can be necessary for patients with a high symptomatic strain, mostly accompanied by a corresponding mental comorbidity, and/or for patients that can only perceive their psychogenic suffering through somatization into tinnitus. METHODS: We report the results of 368 consecutively treated inpatients with chronic complex tinnitus. Patients' audiometric data were collected, and at the beginning and end of treatment, the Mini-Tinnitus Questionnaire (Mini-TQ12; Hiller und Goebel) was completed, as was the German version of the Hospitality Anxiety and Depression Score (HADS). Effect sizes were calculated for both questionnaires. Mean treatment duration was 38.8 days (standard deviation, SD: 13.6 days). The main therapeutic elements were intensive disorder-specific neurotologic counselling and psychoeducation; improvement of hearing by fitting of hearing aids, complemented by an individualized hearing therapy; and intensive individual and group-based psychotherapy. RESULTS: In addition to tinnitus, 82.1% of the patients had reduced hearing requiring rehabilitation with hearing aids. After hospitalization, a highly significant improvement in tinnitus strain could be demonstrated by the Mini-TQ12. Furthermore, a significant reduction in the depression and anxiety components of HADS was also achieved, with high effect sizes of 1.6 to 2.2. No reduction of tinnitus symptoms to a medium- or low-range level was experienced by 8.9% of patients. CONCLUSION: With corresponding symptomatic suffering, disorder-specific inpatient tinnitus treatment comprising neurotologic and psychosomatic alignment can achieve medium- to high-range therapeutic effects.

Hearing-aid use and its determinants in the UK National Health Service: a cross-sectional study at the Royal Surrey County Hospital.

OBJECTIVES: The aim of this study was to investigate the rate of and factors contributing to non-adherence to hearing-aid use in the UK National Health Service. DESIGN: A cross-sectional postal questionnaire survey. STUDY SAMPLE: A questionnaire, including the International Outcome Inventory for Hearing Aids, was sent to all patients fitted with hearing aids at the Royal Surrey County Hospital between 2011 and 2012 (N = 1874). A total of 1023 questionnaires were completed and returned (response rate of 55%). RESULTS: A total of 29% of responders did not use their hearing aids on a regular basis (i.e. used them less than four hours per day). Non-regular use was more prevalent in new (40%) than in existing patients (11%). Factors that reduced the risk of non-regular use included bilateral versus unilateral amplification, and moderate or severe hearing loss in the better ear. 16% of responders fitted with bilateral amplification used only one of their hearing aids. CONCLUSIONS: The level of non-regular use of hearing aids in NHS found in this study was comparable to those for other countries. Additional support might be needed for patients at a higher risk of non-regular use.

Development of a loudness normalisation strategy for combined cochlear implant and acoustic stimulation.

Users of a cochlear implant together with a hearing aid in the non-implanted ear currently use devices that were developed separately and are often fitted separately. This results in very different growth of loudness with level in the two ears, potentially leading to decreased wearing comfort and suboptimal perception of interaural level differences. A loudness equalisation strategy, named 'SCORE bimodal', is proposed. It equalises loudness growth for the two modalities using existing models of loudness for acoustic and electric stimulation, and is suitable for implementation in wearable devices. Loudness balancing experiments were performed with six bimodal listeners to validate the strategy. In a first set of experiments, the function of each loudness model used was validated by balancing the loudness of four harmonic complexes of different bandwidths, ranging from 200 Hz to 1000 Hz, separately for each ear. Both the electric and acoustic loudness models predicted the data well. In a second set of experiments, binaural balancing was done for the same stimuli. It was found that SCORE significantly improved binaural balance.

Patient preferences and willingness to pay for tinnitus treatments.

PURPOSE: There will likely be several different tinnitus treatments necessary, and it is important to understand patient preferences and factors that might contribute to treatment acceptability. This study explores the acceptability of a wide range of different tinnitus treatments, from noninvasive wearable devices to surgically implanted devices in the brain. Understanding how tinnitus sufferers consider and rank such options and how they might be influenced by their own perception of the severity of their tinnitus could help clinicians, researchers, and companies plan future efforts for approaching new treatments. DATA COLLECTION AND ANALYSIS: 197 tinnitus self-help group attendees rated their acceptance of treatments on a scale from 0 (not acceptable) to 100 (fully acceptable). The treatments included external devices, medications, cochlear implants, an implant on the brain surface, and an implant in the brain. They were also asked how much they would pay for successful treatments. RESULTS: There was a significant correlation between loudness and annoyance (r = .78). To reduce tinnitus by half, an "acceptable" response between 91 and 100 was reported by 30% of the respondents for devices, by 52% for pills, by 25% for cochlear implants, by 13% for implants on the brain surface, and by 13% for implants in the brain. To reduce tinnitus completely, a 91-100 acceptable response was reported by 42% for devices, by 62% for pills, by 38% for cochlear implants, by 21% for implants on the brain surface, and by 19% for implants in the brain. To reduce tinnitus completely, participants most commonly selected to pay at least $5000, and 20.3% were willing to pay as much as $25,000. The ratings of tinnitus loudness and annoyance were positively correlated with the likelihood of using any treatment. Surprisingly, there was a weak relationship between annoyance and the amount they were willing to pay. CONCLUSIONS: Tinnitus patients are prepared to accept a wide variety of treatments. Medications are the most acceptable. Invasive procedures can also be acceptable to many, particularly if they provide complete relief.

Partial deafness treatment.

The authors present the accepted strategy of Partial Deafness Treatment (PDT) based on long-term observation and results: 8-years long in adult patients and over 5-years long in children. In therapy, there are two fundamental modes of complementary stimulation in cases of moderate to severe hearing loss. One of them is the acoustic stimulation (AS), comprising patients who use amplification with hearing aid (HA) and/or middle ear implant (MEI). The other mode, presented by the authors in this study, is the electric stimulation using cochlear implant (PDCI). The entire material in this mode is divided into three groups: 1. Electrical Complement (EC); 2. Electric Acoustic Stimulation (EAS); and 3. Electric Stimulation (ES). Surgical approach in PDT is based on the 6-steps method, emphasizing round window approach to the scala tympani. The results obtained in the long-term follow-up shows the preservation of preoperative hearing in 97% of subjects. Overall, for all audiometric frequencies the differences in mean pre- and mean postoperative thresholds, measured before surgery and 3 months afterwards were not statistically significant (p>0.05). In all four groups we observed a significant increase in scores between pre-operative and 12 months after surgery both under quiet and noisy conditions. The presented concept, supported by the substantial material and long-term follow-up, allows the comprehensive approach to the treatment of partial deafness using different modes of stimulation.

Users' experience of a cochlear implant combined with a hearing aid.

This study examined: (1) the prevalence of hearing-aid use in a clinical population of adults with unilateral cochlear implants, (2) the relationship between hearing-aid use, severity of hearing loss, duration of deafness and duration of cochlear implant use, and (3) the benefits of bimodal hearing from the users' perspective. Using a retrospective design, 31 adults were identified as bimodal users, and 93 adults implanted in the same period were identified as non hearing-aid users. The two groups were similar in regards to duration of deafness but differed in severity of hearing loss and time since implantation. Questionnaires examining frequency and situations of hearing-aid use were completed by 24 of 31 bimodal users. Fifteen of these 24 adults reported hearing-aid use more than 50% of the time. These findings suggest that, of the 72 adults in this study with useable hearing (pure-tone average better than 110 dB), about 30% or less regularly combined a hearing aid and cochlear implant. The questionnaire results suggest that regular bimodal users prefer bimodal hearing across a variety of listening environments such as music, noise, and reverberation.

Objective estimation of the listening effort: towards a neuropsychological and neurophysical model.

Modern hearing aid fitting could be revolutionized by the availability of objective methods for the listening effort estimation. However experimental and theoretical research dealing with this subject is still in its infancy. In this paper we present first results towards a neuropsychological and neurophysical model for the objective estimation of the listening effort by electroencephalographic data. Our model is based on intended endogenously driven top-down projections represented by corticothalamic feedback dynamics for auditory stream selection and their large-scale correlates in auditory evoked late responses. The predictions of the presented model are compared to experimental data obtained during different auditory tasks which required a graduated effort for their solutions. The experimental data verified the model predictions.It is concluded that the proposed neuropsychological and neurophysical modeling of stream selection provides an appropriate framework for listening effort estimation. The presented preliminary results of an ongoing study are encouraging,however, further focal research is necessary in order to estimate in how far the presented model and future extensions might support modern hearing aid fitting in practice.

Acceptable noise level as a predictor of hearing aid use.

Acceptable noise level (ANL) measures a listener's reaction to background noise while listening to speech. Relations among hearing aid use and ANL, speech in noise (SPIN) scores, and listener characteristics (age, gender, pure-tone average) were investigated in 191 listeners with hearing impairment. Listeners were assigned to one of three groups based on patterns of hearing aid use: full-time use (whenever hearing aids are needed), part-time use (occasional use), or nonuse. Results showed that SPIN scores and listener characteristics were not related to ANL or hearing aid use. However, ANLs were related to hearing aid use. Specifically, full-time hearing aid users accepted more background noise than part-time users or nonusers, yet part-time users and nonusers could not be differentiated. Thus, a prediction of hearing aid use was examined by comparing part-time users and nonusers (unsuccessful hearing aid users) with full-time users (successful hearing aid users). Regression analysis determined that unaided ANLs could predict a listener's success of hearing aids with 85% accuracy.

[Tinnitus in elderly patients]. / Szum uszny u chorych w podeszlym wieku.

Tinnitus is the perceived sensation of sound in the absence of acoustic stimulation. Spontaneous idiopathic tinnitus is a significant interdisciplinary therapeutic problem. In elderly patients it most frequently coexists with sensorineural hearing loss. The chief idea of tinnitus retraining therapy (TRT) in treatment of chronic tinnitus consists of following strategies: low level and broad band noise surroundings, diversion of the attention to other things and psychological counseling and therapy. The purpose of this study was to verify the benefits and ramifications of tinnitus retraining therapy in elderly patients suffering from chronic tinnitus with sensorineural hearing loss. Methods 30 subjects aged 65-90 years suffering from chronic tinnitus and sensorineural hearing loss were questioned about features of the tinnitus using a set of standardised questions. All of them were fitted with modern digital hearing aids and questioned about subjective hearing results after a month of follow-up. Main result 24 of the patients declared to have had considerable improvement in tolerance of the tinnitus. Main conclusion Fitting with hearing aids is an effective way of treatment in the majority of elderly patients with chronic tinnitus. The effectiveness of supplying elderly patients with hearing aids for tinnitus management depended in our group of patients on whether the patient had good speech understanding prior to fitting with hearing aids (speech discrimination score below and above 80%).