A Scoping Review of Studies Comparing Outcomes for Children With Severe Hearing Loss Using Hearing Aids to Children With Cochlear Implants.

OBJECTIVES: Clinical practice regarding children's candidature for cochlear implantation varies internationally, albeit with a recent global trend toward implanting children with more residual hearing than in the past. The provision of either hearing aids or cochlear implants can influence a wide range of children's outcomes. However, guidance on eligibility and suitability for implantation is often based on a small number of studies and a limited range of speech perception measures. No recent reviews have catalogued what is known about comparative outcomes for children with severe hearing-loss using hearing aids to children using cochlear implants. This article describes the findings of a scoping review that addressed the question "What research has been conducted comparing cochlear implant outcomes to outcomes in children using hearing aids with severe hearing-loss in the better-hearing ear?" The first objective was to catalogue the characteristics of studies pertinent to these children's candidature for cochlear implantation, to inform families, clinicians, researchers, and policy-makers. The second objective was to identify gaps in the evidence base, to inform future research projects and identify opportunities for evidence synthesis. DESIGN: We included studies comparing separate groups of children using hearing aids to those using cochlear implants and also repeated measures studies comparing outcomes of children with severe hearing loss before and after cochlear implantation. We included any outcomes that might feasibly be influenced by the provision of hearing aids or cochlear implants. We searched the electronic databases Medline, PubMed, and CINAHL, for peer-reviewed journal articles with full-texts written in English, published from July 2007 to October 2019. The scoping methodology followed the approach recommended by the Joanna Briggs Institute regarding study selection, data extraction, and data presentation. RESULTS: Twenty-one eligible studies were identified, conducted across 11 countries. The majority of children studied had either congenital or prelingual hearing loss, with typical cognitive function, experience of spoken language, and most implanted children used one implant. Speech and language development and speech perception were the most frequently assessed outcomes. However, some aspects of these outcomes were sparsely represented including voice, communication and pragmatic skills, and speech perception in complex background noise. Two studies compared literacy, two sound localization, one quality of life, and one psychosocial outcomes. None compared educational attainment, listening fatigue, balance, tinnitus, or music perception. CONCLUSIONS: This scoping review provides a summary of the literature regarding comparative outcomes of children with severe hearing-loss using acoustic hearing aids and children using cochlear implants. Notable gaps in knowledge that could be addressed in future research includes children's quality of life, educational attainment, and complex listening and language outcomes, such as word and sentence understanding in background noise, spatial listening, communication and pragmatic skills. Clinician awareness of this sparse evidence base is important when making management decisions for children with more residual hearing than traditional implant candidates. This review also provides direction for researchers wishing to strengthen the evidence base upon which clinical decisions can be made.

Insomnia, Anxiety and Depression in Adult Cochlear Implant Users With Tinnitus.

OBJECTIVE: Determine the prevalence of clinical insomnia and its associations with anxiety, depression, and tinnitus in adult cochlear implant (CI) users. DESIGN: Self-reported information on tinnitus, sleep, and demographic variables was collected from adult CI users (n = 127). Tinnitus presence, its persistence, related emotional distress, and difficulties with sleep were assessed using questions from the UK Biobank study (www.ukbiobank.ac.uk). Tinnitus-related handicap was assessed using the Tinnitus Handicap Inventory. Clinical insomnia symptoms were characterized using the Insomnia Severity Index (ISI), and clinical anxiety and depression symptoms using the Hospital Anxiety and Depression Scale (HADS). Regression models were used to compare the data from CI users with and without tinnitus, and to test the associations between clinical insomnia, anxiety, depression and tinnitus handicap. RESULTS: About a half (53%) of CI users reported tinnitus, of whom 54% described it as persistent, 41% as emotionally distressing and 73% reported having difficulties with sleep based on the UK Biobank questions. The ISI suggested that clinically abnormal insomnia symptoms were more likely to occur with tinnitus (odds ratio [OR] = 2.60, 95% confidence interval 1.04 to 6.45; p = 0.040) and were found in 41% of CI users with tinnitus. Post-hoc exploratory analyses on the ISI suggested that CI users with tinnitus experienced greater levels of difficulty falling asleep, lower satisfaction with sleep patterns, greater interference of sleep problems with daily activities, and a greater impact on their quality of life. The HADS scores suggested that those with tinnitus were also more likely to have clinically abnormal anxiety (42%; OR = 3.50, 95% confidence interval 1.49 to 8.22; p = 0.004) and depression symptoms (14%; OR = 6.18, 95% confidence interval 1.17 to 32.82; p = 0.032). The clinical insomnia observed in CI users with tinnitus was associated with tinnitus handicap (p = 0.028), and the levels of clinical anxiety (p = 0.012) and depression (p < 0.001). CONCLUSIONS: Clinically abnormal insomnia symptoms are prevalent, potentially affecting over 40% of CI users with tinnitus. The associations between clinical insomnia, anxiety, and depression symptoms, and tinnitus-related handicap suggest that all of these symptoms should be considered when assessing the tinnitus-related burden and its impact on the quality of life after cochlear implantation. The present findings also have potential implications for the clinical management of CI recipients with tinnitus, in whom it may be advisable to monitor sleep problems so that they can be addressed where appropriate. Further research is needed to investigate the mechanisms and causal links behind insomnia and tinnitus-related symptoms in this population. Future studies should also investigate the feasibility and effectiveness of night time use of CIs to alleviate tinnitus-related insomnia. The potential impact of insomnia on the quality of life of CI users with tinnitus highlights the importance of including sleep measures in future evaluations of the effectiveness of cochlear implantation for the alleviation of tinnitus.

Associations Between Hearing Health and Well-Being in Unilateral Hearing Impairment.

OBJECTIVES: To determine population-based risks of adverse effects on hearing and well-being outcomes associated with unilateral hearing impairment. DESIGN: A group of 40- to 69-year-old adults (n = 861) who reported being able to hear only in one ear and having speech reception thresholds (SRTs) in noise indicating normal hearing in that ear (SRTN/-) was selected from the UK Biobank cohort. The UK Biobank participants with SRTs indicating either normal (SRTN/N, n = 95,514) or symmetrically impaired hearing in both ears (SRTI/I, n = 17,429) were selected as comparison groups. Self-reported difficulty following conversations in noise, tinnitus presence, feeling depressed, lonely, unhappy, and being in poor health or dissatisfied with health were selected as hearing and well-being outcomes. Logistic regression models were used to evaluate the risks of reporting adverse outcomes associated with SRTN/- compared with SRTN/N and SRTI/I while controlling for numerous factors linked to hearing and general health. RESULTS: People with SRTN/- were significantly more likely to report difficulties following conversations in noise (odds ratio, 10.61; 95% confidence interval, 8.83 to 12.75), tinnitus (4.04; 3.51 to 4.66), poor health (1.35; 1.15 to 1.58), health dissatisfaction (1.22; 1.00 to 1.47), and loneliness (1.28; 1.08 to 1.51) compared with people with SRTN/N. Well-being outcomes were similar in the SRTN/- and SRTI/I groups. However, difficulties following conversations in noise (5.35; 4.44 to 6.44) and tinnitus presence (2.66; 2.31 to 3.08) were significantly more likely with SRTN/- than with SRTI/I. The SRTN/- was associated with increased risk of self-reported poor health by 18% (relative risk, 1.18; 95% confidence interval, 1.06 to 1.32) and loneliness by 24% (1.24; 1.07 to 1.43) compared with SRTN/N. The risk of reporting difficulties following conversations in noise increased by 64% (1.64; 1.58 to 1.71) and tinnitus presence by 84% (1.84; 1.69 to 2.01) compared with SRTI/I. The effect of SRTN/- on reporting poor health was similar to that from having other health problems such as hypertension or high cholesterol. CONCLUSIONS: The large increases in the risks of reporting adverse hearing-related outcomes associated with unilateral hearing impairment suggest its specific impact on hearing function in everyday situations. The increased risk of loneliness and poor health indicates that one normally functioning ear is also insufficient to protect against the adverse psychosocial impacts of unilateral hearing impairment. This impact was still significant after controlling for various health-related factors and can lead to perception of poor health comparable to that with having medical problems contributing to life-threatening conditions such as heart disease. The findings suggest the need for effective interventions to address the hearing-related problems and their impact on well-being in people with unilateral hearing impairment.

Tinnitus and Sleep Difficulties After Cochlear Implantation.

OBJECTIVES: To estimate and compare the prevalence of and associations between tinnitus and sleep difficulties in a sample of UK adult cochlear implant users and those identified as potential candidates for cochlear implantation. DESIGN: The study was conducted using the UK Biobank resource, a population-based cohort of 40- to 69-year olds. Self-report data on hearing, tinnitus, sleep difficulties, and demographic variables were collected from cochlear implant users (n = 194) and individuals identified as potential candidates for cochlear implantation (n = 211). These "candidates" were selected based on (i) impaired hearing sensitivity, inferred from self-reported hearing aid use and (ii) impaired hearing function, inferred from an inability to report words accurately at negative signal to noise ratios on an unaided closed-set test of speech perception. Data on tinnitus (presence, persistence, and related distress) and on sleep difficulties were analyzed using logistic regression models controlling for gender, age, deprivation, and neuroticism. RESULTS: The prevalence of tinnitus was similar among implant users (50%) and candidates (52%; p = 0.39). However, implant users were less likely to report that their tinnitus was distressing at its worst (41%) compared with candidates (63%; p = 0.02). The logistic regression model suggested that this difference between the two groups could be explained by the fact that tinnitus was less persistent in implant users (46%) compared with candidates (72%; p < 0.001). Self-reported difficulties with sleep were similar among implant users (75%) and candidates (82%; p = 0.28), but participants with tinnitus were more likely to report sleep difficulties than those without (p < 0.001). The prevalence of sleep difficulties was not related to tinnitus persistence (p = 0.28) or the extent to which tinnitus was distressing (p = 0.55). CONCLUSIONS: The lack of association between tinnitus persistence and sleep difficulties is compatible with the notion that tinnitus is suppressed in implant users primarily during active electrical stimulation and may return when the implant is switched off at night time. This explanation is supported by the similar prevalence of sleep problems among implant users and potential candidates for cochlear implantation, despite differences between the groups in tinnitus persistence and related emotional distress. Cochlear implantation may therefore not be an appropriate intervention where the primary aim is to alleviate sleep difficulties.

An exploration of psychological symptom-based phenotyping of adult cochlear implant users with and without tinnitus using a machine learning approach.

The identification of phenotypes within populations with troublesome tinnitus is an important step towards individualizing tinnitus treatments to achieve optimal outcomes. However, previous application of clustering algorithms has called into question the existence of distinct tinnitus-related phenotypes. In this study, we attempted to characterize patients' symptom-based phenotypes as subpopulations in a Gaussian mixture model (GMM), and subsequently performed a comparison with tinnitus reporting. We were able to effectively evaluate the statistical models using cross-validation to establish the number of phenotypes in the cohort, or a lack thereof. We examined a cohort of adult cochlear implant (CI) users, a patient group for which a relation between psychological symptoms (anxiety, depression, or insomnia) and trouble tinnitus has previously been shown. Accordingly, individual item scores on the Hospital Anxiety and Depression Scale (HADS; 14 items) and the Insomnia Severity Index (ISI; 7 items) were selected as features for training the GMM. The resulting model indicated four symptom-based subpopulations, some primarily linked to one major symptom (e.g., anxiety), and others linked to varying severity across all three symptoms. The presence of tinnitus was self-reported and tinnitus-related handicap was characterized using the Tinnitus Handicap Inventory. Specific symptom profiles were found to be significantly associated with CI users' tinnitus characteristics. GMMs are a promising machine learning tool for identifying psychological symptom-based phenotypes, which may be relevant to determining appropriate tinnitus treatment.

Effects of cognitive behavioural therapy on insomnia in adults with tinnitus: Systematic review and meta-analysis of randomised controlled trials.

Insomnia is common in patients with tinnitus and negatively affects tinnitus symptoms and quality of life. This systematic review aimed to synthesise evidence of the effectiveness of cognitive behavioural therapy (CBT) based interventions on insomnia in adults with tinnitus. We conducted a comprehensive database search (MEDLINE, CINAHL, Web of Science, CENTRAL, ClinicalTrials.gov and PROSPERO) for published, unpublished and ongoing randomised controlled trials of CBT in adults with tinnitus. Five trials met the inclusion criteria for the systematic review, with four of these providing data for the meta-analysis. This demonstrated a statistically significant reduction in Insomnia Severity Index (a standard diagnostic questionnaire of insomnia used in clinical settings) following CBT (-3.28, 95% CI -4.51, -2.05, P=<0.001). There was no evidence of statistical heterogeneity (I2 = 0%). Risk of bias was considered low in all categories except blinding of participants, personnel, and/or the assessment of outcomes. Here, for the first time, we demonstrate that CBT-based interventions can significantly improve sleep in adults with tinnitus.

Indications for temporal fine structure contribution to co-modulation masking release.

The contribution of temporal fine structure (TFS) information to co-modulation masking release (CMR) was examined by comparing CMR obtained with unprocessed or vocoded stimuli. Tone thresholds were measured in the presence of a sinusoidally amplitude-modulated on-frequency band (OFB) of noise and zero, two, or four flanking bands (FBs) of noise whose envelopes were either co- or anti-modulated with the OFB envelope. Vocoding replaced the TFS of the tone and masker with unrelated TFS of noise or sinusoidal carriers. Maximum CMR of 11 dB was found as the difference between the co- and anti-modulated conditions for unprocessed stimuli. After vocoding, tone thresholds increased by 7 dB, and CMR was reduced to about 4 dB but remained significant. The magnitude of CMR was similar for both the sine and the noise vocoder. Co-modulation improved detection in the vocoded condition despite the absence of the tone-masker TFS interactions; thus CMR appears to be a robust mechanism based on across-frequency processing. TFS information appears to contribute to across-channel CMR since the magnitude of CMR was significantly reduced after vocoding. Since CMR was evidenced despite vocoding, it is hoped that co-modulation would also improve detection in cochlear-implant listening.

Effects of Tinnitus on Cochlear Implant Programming.

Clinical observations suggest that tinnitus may interfere with programming cochlear implants (CIs), the process of optimizing the transmission of acoustic information to support speech perception with a CI. Despite tinnitus being highly prevalent among CI users, its effects and impact on CI programming are obscure. This study characterized the nature, time-course, and impact of tinnitus effects encountered by audiologists and patients during programming appointments. Semistructured interviews with six CI audiologists were analyzed thematically to identify tinnitus effects on programming and related coping strategies. Cross-sectional surveys with 67 adult CI patients with tinnitus and 20 CI audiologists in the United Kingdom examined the prevalence and time-course of those effects. Programming parameters established at CI activation appointments of 10 patients with tinnitus were compared with those of 10 patients without tinnitus. On average, 80% of audiologists and 45% of patients reported that tinnitus makes measurements of threshold (T) levels more difficult because patients confuse their tinnitus with CI stimulation. Difficulties appeared most common at CI activation appointments, at which T levels were significantly higher in patients with tinnitus. On average, 26% of patients reported being afraid of "loud" CI stimulation worsening tinnitus, affecting measurements of loudest comfortable (C) stimulation levels, and 34% of audiologists reported observing similar effects. Patients and audiologists reported that tinnitus makes programming appointments more difficult and tiresome for patients. The findings suggest that specific programming strategies may be needed during CI programming with tinnitus, but further research is required to assess the potential impact on outcomes including speech perception.

Whole scalp resting state EEG of oscillatory brain activity shows no parametric relationship with psychoacoustic and psychosocial assessment of tinnitus: A repeated measures study.

Tinnitus is a perception of sound that can occur in the absence of an external stimulus. A brief review of electroencephalography (EEG) and magnetoencephalography (MEG) literature demonstrates that there is no clear relationship between tinnitus presence and frequency band power in whole scalp or source oscillatory activity. Yet a preconception persists that such a relationship exists and that resting state EEG could be utilised as an outcome measure for clinical trials of tinnitus interventions, e.g. as a neurophysiological marker of therapeutic benefit. To address this issue, we first examined the test-retest correlation of EEG band power measures in tinnitus patients (n = 42). Second we examined the evidence for a parametric relationship between numerous commonly used tinnitus variables (psychoacoustic and psychosocial) and whole scalp EEG power spectra, directly and after applying factor reduction techniques. Test-retest correlation for both EEG band power measures and tinnitus variables were high. Yet we found no relationship between whole scalp EEG band powers and psychoacoustic or psychosocial variables. We conclude from these data that resting state whole scalp EEG should not be used as a biomarker for tinnitus and that greater caution should be exercised in regard to reporting of findings to avoid confirmation bias. The data was collected during a randomised controlled trial registered at ClinicalTrials.gov (Identifier: NCT01541969).

Comodulation masking release in electric hearing.

Comodulation masking release (CMR) is an improvement in the detection threshold of a masked signal that occurs when the masker envelopes are correlated across frequency (i.e., comodulation). CMR can be observed when flanking bands (FBs) of noise co-modulated with an on-frequency band (OFB) noise masker are added at remote frequencies (CMR1), or when co-modulated envelopes are used instead of anti-modulated envelopes (OFB and FB envelopes out of phase, CMR2). For FBs widely separated from the OFB, this process is assumed to rely mostly on across-channel comparison of temporal envelopes. Since cochlear implants (CIs) rely predominantly on the transmission of envelope cues, we investigated if CMR can be observed in electric hearing. We stimulated the auditory nerve of eight CI users with trains of modulated electric pulses presented on an OFB electrode alone, or together with pulse trains on one or two FB electrodes. Participants had to detect signal-induced changes in the envelope of an electric pulse train masker presented on the OFB electrode. Envelopes on FB electrodes were either co-modulated or anti-modulated with the envelope of the OFB masker. We observed CMR1 in one of the eight CI users. However, significant CMR2 was observed in most CI users. Reducing amplitude-modulation rate from 20 to 8 Hz, reducing envelopes' randomness or increasing electrode separation did not generally improve CMR1, but increased the prevalence of CMR2. The present results suggest that comodulation of envelopes can aid signal detection in electric hearing.

Relation between speech-in-noise threshold, hearing loss and cognition from 40-69 years of age.

BACKGROUND: Healthy hearing depends on sensitive ears and adequate brain processing. Essential aspects of both hearing and cognition decline with advancing age, but it is largely unknown how one influences the other. The current standard measure of hearing, the pure-tone audiogram is not very cognitively demanding and does not predict well the most important yet challenging use of hearing, listening to speech in noisy environments. We analysed data from UK Biobank that asked 40-69 year olds about their hearing, and assessed their ability on tests of speech-in-noise hearing and cognition. METHODS AND FINDINGS: About half a million volunteers were recruited through NHS registers. Respondents completed 'whole-body' testing in purpose-designed, community-based test centres across the UK. Objective hearing (spoken digit recognition in noise) and cognitive (reasoning, memory, processing speed) data were analysed using logistic and multiple regression methods. Speech hearing in noise declined exponentially with age for both sexes from about 50 years, differing from previous audiogram data that showed a more linear decline from <40 years for men, and consistently less hearing loss for women. The decline in speech-in-noise hearing was especially dramatic among those with lower cognitive scores. Decreasing cognitive ability and increasing age were both independently associated with decreasing ability to hear speech-in-noise (0.70 and 0.89 dB, respectively) among the population studied. Men subjectively reported up to 60% higher rates of difficulty hearing than women. Workplace noise history associated with difficulty in both subjective hearing and objective speech hearing in noise. Leisure noise history was associated with subjective, but not with objective difficulty hearing. CONCLUSIONS: Older people have declining cognitive processing ability associated with reduced ability to hear speech in noise, measured by recognition of recorded spoken digits. Subjective reports of hearing difficulty generally show a higher prevalence than objective measures, suggesting that current objective methods could be extended further.

Evaluation of the acoustic coordinated reset (CR®) neuromodulation therapy for tinnitus: study protocol for a double-blind randomized placebo-controlled trial.

BACKGROUND: Current theories of tinnitus assume that the phantom sound is generated either through increased spontaneous activity of neurons in the auditory brain, or through pathological temporal firing patterns of the spontaneous neuronal discharge, or a combination of both factors. With this in mind, Tass and colleagues recently tested a number of temporally patterned acoustic stimulation strategies in a proof of concept study. Potential therapeutic sound regimes were derived according to a paradigm assumed to disrupt hypersynchronous neuronal activity, and promote plasticity mechanisms that stabilize a state of asynchronous spontaneous activity. This would correspond to a permanent reduction of tinnitus. The proof of concept study, conducted in Germany, confirmed the safety of the acoustic stimuli for use in tinnitus, and exploratory results indicated modulation of tinnitus-related pathological synchronous activity with potential therapeutic benefit. The most effective stimulation paradigm is now in clinical use as a sound therapy device, the acoustic coordinated reset (CR®) neuromodulation (Adaptive Neuromodulation GmbH (ANM), Köln, Germany). METHODS/DESIGN: To measure the efficacy of CR® neuromodulation, we devised a powered, two-center, randomized controlled trial (RCT) compliant with the reporting standards defined in the Consolidated Standards of Reporting Trials (CONSORT) Statement. The RCT design also addresses the recent call for international standards within the tinnitus community for high-quality clinical trials. The design uses a between-subjects comparison with minimized allocation of participants to treatment and placebo groups. A minimization approach was selected to ensure that the two groups are balanced with respect to age, gender, hearing, and baseline tinnitus severity. The protocol ensures double blinding, with crossover of the placebo group to receive the proprietary intervention after 12 weeks. The primary endpoints are the pre- and post-treatment measures that provide the primary measures of efficacy, namely a validated and sensitive questionnaire measure of the functional impact of tinnitus. The trial is also designed to capture secondary changes in tinnitus handicap, quality (pitch, loudness, bandwidth), and changes in tinnitus-related pathological synchronous brain activity using electroencephalography (EEG). DISCUSSION: This RCT was designed to provide a confident high-level estimate of the efficacy of sound therapy using CR® neuromodulation compared to a well-matched placebo intervention, and uniquely in terms of sound therapy, examine the physiological effects of the intervention against its putative mechanism of action. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01541969.