Association between Hyperacusis and Tinnitus

Objective autonomic signatures of tinnitus and sound sensitivity disorders

Hypersensitivity, phantom percepts, and sensory reactivity are core features of many neurological disorders. Direct, objective measurements of these features have proven difficult to identify, leaving subjective questionnaires as the primary means of assessing sensory disorder severity. Here, we studied neurotypical adults (n = 50) or adults with sound sensitivity and tinnitus (ringing of the ears) (n = 47) and discovered a previously unidentified set of objective measurements that predicted individual differences in the Tinnitus Handicap Inventory (THI) and Hyperacusis Questionnaire (HQ). A neurophysiological assessment of central auditory gain demonstrated an elevation in participants with tinnitus and sound sensitivity but no association with symptom severity. Instead, accurate predictors of individual THI and HQ scores were identified in pupil dilations and facial movements elicited by emotionally evocative sounds. These findings highlight autonomic signatures of disrupted affective sound processing in persons with tinnitus and sound sensitivity disorders and introduce new approaches for their objective measurement.

Frequency of Oral Behaviors as a Risk Factor for Somatosensory Tinnitus

Introduction  Somatosensory tinnitus is a type of tinnitus that can be modified by somatosensory stimuli from the cervical spine and temporomandibular area. Temporomandibular disorders and oral behaviors are associated with a higher prevalence of somatosensory tinnitus, and this association is described in the literature as part of the diagnosis of this condition. Objective  To verify the association between somatosensory tinnitus and oral behaviors. Methods  Patients were recruited from an Orofacial Pain outpatient clinic and from Head and Neck Unit. All participants underwent anamnesis, physical examination and completed the Oral Behaviors Checklist questionnaire. Forty-six patients were divided into 2 groups, each consisting of 23 patients: somatosensory tinnitus group (STG) and a comparison group (CG), with subjective tinnitus. Data were gathered and analyzed using the Jamovi software (open source) and a significance level of 5% was adopted. Somatosensory tinnitus was associated with dizziness and neck and temporomandibular joint pain. Results  There was an association between a higher Oral Behaviors Checklist score and the presence of somatosensory tinnitus. For each point marked on Oral Behaviors Checklist, there was an 8.2% greater chance of having somatosensory tinnitus. Tinnitus modulation through somatic maneuvers and palpation of masticatory and cervical muscles was significantly associated with somatosensory tinnitus. Conclusion  Dizziness and neck and temporomandibular joint pain are associated with the presence of somatosensory tinnitus. Probable sleep and awake bruxism are not exclusive behaviors of somatosensory tinnitus patients. However, their frequency may impact its presence.

Work absence and ability in tinnitus patients: the role of hyperacusis and tinnitus severity

OBJECTIVE

Identify factors predicting work capacity among patients with tinnitus and hyperacusis.

DESIGN AND STUDY SAMPLE

This study employed a cross-sectional design, collecting data from four Norwegian audiology clinics (N = 80) and two Norwegian rehabilitation centres (N = 47). The patients in this study were invited to complete a web-based questionnaire.

RESULTS

This study found significant positive correlations between levels of tinnitus, hyperacusis, and mental distress (rs in the range .51 - .74). Logistic regression models showed that reduced work capacity was predicted by both tinnitus (OR = 1.07) and hyperacusis (OR = 1.13), and that hyperacusis predicted work absence (OR = 1.08).

CONCLUSION

The findings demonstrate a moderate association between tinnitus and hyperacusis (r = .51), with both conditions affecting the work capacity of more than 50% of participants in the study. Moreover, the results indicate that the severity of tinnitus and hyperacusis is directly related to impaired work capacity and higher rates of work absence.

Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group

BACKGROUND

Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.

METHODS

A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7-9) and ≤ 15% disagreement (score of 1-3). Statistical measures such as content validity ratio and Kendall's coefficient of concordance (W) were calculated to assess agreement levels.

RESULTS

Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall's W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall's W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.

CONCLUSION

This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.

The Association Between Temporomandibular Disorders and Tinnitus: Evidence and Therapeutic Perspectives from a Systematic Review

Background/Objectives: Tinnitus, often described as a ringing in the ears, affects a significant portion of the population, varying in perception and severity. Methods: This systematic review investigates the correlation between tinnitus and temporomandibular joint disorders (TMDs) within a PRISMA-compliant framework, ensuring methodological transparency and rigor. Using databases, such as PubMed, Scopus, and Web of Science, we analyzed studies from the past decade to evaluate clinical and observational evidence. Results: A significant association between TMD and tinnitus was found, with somatosensory and neuroplastic mechanisms contributing to this relationship. Key therapeutic approaches identified include manual therapy and multidisciplinary treatments, demonstrating potential clinical efficacy. Conclusions: However, the available evidence remains inconsistent, emphasizing the need for further research with standardized methodologies to improve understanding and refine therapeutic strategies. This review provides a foundation for future studies aiming to enhance tinnitus management by addressing underlying TMD-related mechanisms.

Audiometric Profiles Across a Clinical Population of Children With Hyperacusis

PURPOSE

Hyperacusis (sound sensitivity) is well documented among adults, but little is known about hyperacusis in children. Here, we assess relationships among the presence of hyperacusis, audiometric profiles, and nonauditory factors in a pediatric clinical population.

METHOD

A retrospective review of clinical records from 329 children, ages 2-17 years, was performed to assess the prevalence of hyperacusis and correlations among hearing status, behavioral or communication concerns, and the presence of hyperacusis.

RESULTS

In 329 study participants, 18% reported hyperacusis (58% male and 42% female). No significant sex or age differences were found. Hyperacusis was more likely to occur alongside normal hearing or with unilateral hearing loss relative to bilateral hearing loss. Among children with hyperacusis, there was a high prevalence of audiovestibular problems, mental health concerns, speech and language delays, difficulty in school, and behavioral problems. Tinnitus was also found to be comorbid with hyperacusis, but the comorbidity was less than that reported in adults.

CONCLUSIONS

This study identified common hearing profiles and critical comorbidities in a large clinical cohort of children with hyperacusis. These results demonstrate the urgent need for standardized multidisciplinary assessment and treatment protocols for pediatric hyperacusis.

Association between hospital-diagnosed tinnitus and suicide: A Nationwide Danish longitudinal study

OBJECTIVES

Tinnitus is a source of significant distress among some people. Associations have been suggested between tinnitus and mental disorders, and with suicidal thoughts and attempts. However, whether this extends to suicide in the general population remains uncertain.

METHODS

This is a retrospective cohort study including all individuals aged 15 years or older, using Danish nationwide, longitudinal, population-based register data from 1 January 1990 through 31 December 2021. The main outcome was death by suicide. Poisson regression models were used to estimate adjusted incidence rate ratios (IRR) with the 95% confidence intervals (CI).

RESULTS

Among 7,438,007 individuals (49.8% males) observed over 144,050,344 person-years, 85,677 (57.7% males) were diagnosed with tinnitus. In all, 23,824 suicide deaths were identified, of which 225 had tinnitus. Suicide rates were 24.2 and 16.5 per 100,000 person-years for those with and without tinnitus, respectively, giving an adjusted IRR of 1.4 (95% CI 1.2-1.6). Suicide rates were adjusted for demographic characteristics, concomitant hearing loss, and co-existing mental disorders before tinnitus. Increased suicide rates were linked to a higher number of hospital contacts and to recent hospital contacts, suggesting dose-response and temporal associations.

CONCLUSIONS

The findings reveal an association between tinnitus and suicide, particularly among individuals with co-existing mental disorders. Dose-response and temporal associations were found between tinnitus and suicide. Concurrent hearing loss had no influence on the tinnitus-suicide association. Attention towards patients experiencing tinnitus related distress is warranted, especially those with pre-existing mental disorders.

Tinnitus Prevalence, Associated Characteristics, and Treatment Patterns among Adults in Saudi Arabia

Tinnitus affects millions of people around the world and causes significant negative impacts on their quality of life (QoL). Tinnitus is rarely examined in Saudi Arabia. This study aimed to estimate the prevalence of tinnitus among adults, explore their experience with tinnitus, investigate the impact of tinnitus on their QoL, and discover their tinnitus management methods. A descriptive cross-sectional study design was performed utilizing a non-probability purposive sampling technique and a face-to-face in-person administered questionnaire. Descriptive statistics and a chi-square test were used to assess the data and find any correlation between the variables. Out of 4860 adults, 320 (males: n = 172; females: n = 148; age range = 18-90 years) had tinnitus, mainly described as a daily, gradual, continuous, whistling, and ringing tinnitus in both ears. Tinnitus prevalence was estimated at 6.54% with a slight predominance in males (6.9%) compared with females (6.2%). Most of the participants were unaware of the cause of their tinnitus. The modal value of the severity of tinnitus signals was severe for both genders. The modal value of the impact of tinnitus on the QoL was moderate for males and severe for females. Sleep, social activities, quiet settings, and concentration were largely affected by tinnitus. Significant associations (p < 0.05) between the impact of tinnitus on the QoL and risk factors, such as gender, age, hearing loss, and hyperacusis were determined. Also, the impact of tinnitus on the QoL was significantly associated (p < 0.05) with the duration of complaints and the severity of tinnitus signals. Approximately, 61% of the participants did not use any tinnitus treatment, while the remaining participants usually used hearing aids, medications, and counseling to manage their tinnitus. By increasing awareness, establishing standard practice, developing guidelines for managing tinnitus, expanding access to suitable interventions, and carrying out additional research, adults living with tinnitus in Saudi Arabia will have better support and, ultimately, an enhancement of their overall well-being.

Phenotypic spectrum of tinnitus patients bearing rare ANK2 gene variants

PURPOSE

To describe the clinical, audiological, and psychometric features observed in patients with chronic tinnitus and rare variants in the ANK2 gene.

METHODS

We report a case series of 12 patients with chronic tinnitus and heterozygous variants in the ANK2 gene. Tinnitus phenotyping included audiological (standard and high-frequency audiometry, Auditory Brainstem Responses (ABR) and Auditory Middle Latency Responses (AMLR)), psychoacoustic and psychometric assessment by a Visual Analog Scale (VAS) for tinnitus annoyance, the Tinnitus Handicap Inventory (THI), the test on Hypersensitivity to Sound (THS-GÜF), the Patient Health Questionnaire (PHQ-9), the Hospital Anxiety and Depression Scale (HADS) and the Montreal Cognitive Assessment (MoCA).

RESULTS

All patients reported a persistent, unilateral noise-type tinnitus, mainly described as white noise or narrowband noise. Seven patients (58%) were considered to have extreme phenotype (THI score > 76), and all patients reported some degree of hyperacusis (THS-GÜF score > 18 in 75% of patients). Seven patients scored MoCA < 26, regardless of the age reported, suggesting a mild cognitive disorder. ABR showed no significant differences in latencies and amplitudes between ears with or without tinnitus. Similarly, the latencies of Pa, Pb waves, and NaPa complex in the AMLR did not differ based on the presence of tinnitus. However, there were statistical differences in the amplitudes of Pa waves in AMLR, with significantly greater amplitudes observed in ears with tinnitus.

CONCLUSION

Patients with ANK2 variants and severe tinnitus exhibit an endophenotype featuring hyperacusis, persistent noise-like tinnitus, high-frequency hearing loss, and decreased amplitudes in AMLR. However, anxiety, depression, and cognitive symptoms vary among individuals.

Establishing a Comprehensive Tinnitus Care Pathway-Part 2: Implementation

This article is the second in a two-part series intended to provide guidance related to the essential components of establishing a comprehensive tinnitus care pathway in your clinic. Please see "Part 1: Essential Components" for relevant background information detailing why each of the components described in this article were included.

Sensory Inhibition and Tinnitus: Measurement of Auditory Gating

Tinnitus is the perception of sound without the presence of an external stimulus. The mechanisms associated with tinnitus are not entirely known, making diagnosis and treatment challenging. Although tinnitus mechanisms are not entirely known, there is evidence supporting an association between tinnitus with cochlear damage, reduced inhibition, and atypical cortical function. These mechanisms have been studied in animal models and people with tinnitus using a variety of different approaches. One approach that is a possible indicator of tinnitus in humans is sensory or auditory gating, which is a measure of inhibition. The goals of this article are to (1) review the mechanistic evidence associating tinnitus with cochlear damage and reduced inhibition, (2) discuss evidence of inhibitory impairments in people with tinnitus represented by auditory gating, and (3) address potential future directions to improve our ability to evaluate auditory gating mechanisms in people with tinnitus.

Hyperacusis questionnaire and event-related potential correlation in migraine patients

This study aims to investigate auditory hypersensitivity and cortical function in migraine patients using the Hyperacusis Questionnaire and the Event-Related Potential (ERP) technique. The study analyzes alterations in the latency and amplitude of the event-related potentials MMN and P300 components. The findings contribute to a better understanding of the physiological relationship between migraine and auditory hypersensitivity. Seventeen migraine patients were admitted to the outpatient clinic of the Department of Otorhinolaryngology-Head and Neck Surgery at Peking University People's Hospital from June 2023 to September 2023. Nineteen matched healthy subjects were also selected. All participants underwent the pure tone audiometry and the auditory brainstem response test to determine hearing thresholds, the Hyperacusis Questionnaire, the Tinnitus Handicap Inventory, and an ERP examination. The Oddball classical paradigm was used as the stimulation task, and electroencephalography signals were recorded synchronously. The scores of the Hyperacusis Questionnaire, latency and amplitude of MMN and P300 component were compared between the migraine group and the control group, and their correlation was analyzed. The latency of MMN at the Fz and Cz sites in migraine patients was significantly shorter than that in the control group (P < 0.05), and the amplitudes were significantly higher than those in the control group (P < 0.05). The variances in latency and amplitude of P300 at Cz and Pz sites in migraine patients were not statistically significant when compared with the control group. (P > 0.05). The Hyperacusis Questionnaire was negatively correlated with MMN latency, with a correlation coefficient of - 0.374 (P = 0.025), and positively correlated with MMN amplitude, with a correlation coefficient of 0.378 (P = 0.023). There was no significant similarity between the Hyperacusis Questionnaire and P300 latency and amplitude (P > 0.05). Overall, auditory hypersensitivity was enhanced in individuals with migraines compared to healthy individuals, leading to faster information processing, while there may be less impairment in cognitive function.

Map plasticity following noise exposure in auditory cortex of rats: implications for disentangling neural correlates of tinnitus and hyperacusis

Introduction

Both tinnitus and hyperacusis, likely triggered by hearing loss, can be attributed to maladaptive plasticity in auditory perception. However, owing to their co-occurrence, disentangling their neural mechanisms proves difficult. We hypothesized that the neural correlates of tinnitus are associated with neural activities triggered by low-intensity tones, while hyperacusis is linked to responses to moderate- and high-intensity tones.

Methods

To test these hypotheses, we conducted behavioral and electrophysiological experiments in rats 2 to 8 days after traumatic tone exposure.

Results

In the behavioral experiments, prepulse and gap inhibition tended to exhibit different frequency characteristics (although not reaching sufficient statistical levels), suggesting that exposure to traumatic tones led to acute symptoms of hyperacusis and tinnitus at different frequency ranges. When examining the auditory cortex at the thalamocortical recipient layer, we observed that tinnitus symptoms correlated with a disorganized tonotopic map, typically characterized by responses to low-intensity tones. Neural correlates of hyperacusis were found in the cortical recruitment function at the multi-unit activity (MUA) level, but not at the local field potential (LFP) level, in response to moderate- and high-intensity tones. This shift from LFP to MUA was associated with a loss of monotonicity, suggesting a crucial role for inhibitory synapses.

Discussion

Thus, in acute symptoms of traumatic tone exposure, our experiments successfully disentangled the neural correlates of tinnitus and hyperacusis at the thalamocortical recipient layer of the auditory cortex. They also suggested that tinnitus is linked to central noise, whereas hyperacusis is associated with aberrant gain control. Further interactions between animal experiments and clinical studies will offer insights into neural mechanisms, diagnosis and treatments of tinnitus and hyperacusis, specifically in terms of long-term plasticity of chronic symptoms.

Confirmatory factor analysis of the Tinnitus Impact Questionnaire using data from patients seeking help for tinnitus alone or tinnitus combined with hyperacusis

A confirmatory factor analysis (CFA) of the Tinnitus Impact Questionnaire (TIQ) was performed. In contrast to commonly used tinnitus questionnaires, the TIQ is intended solely to assess the impact of tinnitus by not including items related to hearing loss or tinnitus loudness. This was a psychometric study based on a retrospective cross-sectional analysis of clinical data. Data were available for 155 new patients who had attended a tinnitus and hyperacusis clinic in the UK within a five-month period and had completed the TIQ. The mean age was 54 years (standard deviation = 14 years). The TIQ demonstrated good internal consistency, with Cronbach's α = 0.84 and McDonald's ω = 0.89. CFA showed that two items of the TIQ had low factor loadings for both one-factor and two-factor models and their scores showed low correlations with scores for other items. Bi-factor analysis gave a better fit, indicated by a relative chi-square (χ2) of 18.5, a Root-Mean Square Error of Approximation (RMSEA) of 0.103, a Comparative Fit Index (CFI) of 0.97, a Tucker Lewis Index (TLI) of 0.92, and a Standardized Root-Mean Residual (SPMR) of 0.038. Total TIQ scores were moderately correlated with scores for the Visual Analogue Scale of effect of tinnitus on life and the Screening for Anxiety and Depression-Tinnitus questionnaire, supporting the convergent validity of the TIQ. The TIQ score was not correlated with the pure-tone average hearing threshold, indicating discriminant validity. A multiple-causes multiple-indicator (MIMIC) model showed no influences of age, gender or hearing status on TIQ item scores. The TIQ is an internally consistent tool. CFA suggests a bi-factor model with sufficient unidimensionality to support the use of the overall TIQ score for assessing the impact of tinnitus. TIQ scores are distinct from the impact of hearing impairment among patients who have tinnitus combined with hearing loss.

Tinnitus: A Dimensionally Segregated, yet Perceptually Integrated Heterogeneous Disorder

OBJECTIVES

Tinnitus subtypes are proposed to lie on a continuum of different symptom dimensions rather than be categorical. However, there is no comprehensive empirical data showing this complex relationship between different tinnitus symptoms. The objective of this study is to provide empirical evidence for the dimensional nature of tinnitus and how different auditory and non-auditory symptoms interact with each other through complex interactions. We do this using graph theory, a mathematical tool that empirically maps this complex interaction. This way, graph theory can be utilised to highlight a new and possibly important outlook on how we can understand the heterogeneous nature of tinnitus.

DESIGN

In the current study, we use the screening databases of the Treatment Evaluation of Neuromodulation for Tinnitus-Stage A1 (TENT-A1) and A2 (TENT-A2) randomised trials to delineate the dimensional relationship between different clinical measures of tinnitus as a secondary data analysis. We first calculate the empirical relationship by computing the partial correlation. Following this, we use different measures of centrality to describe the contribution of different clinical measures to the overall network. We also calculate the stability of the network and compare the similarity and differences between TENT-A1 and TENT-A2.

RESULTS

Components of the auditory subnetwork (loudness discomfort level, sound sensitivity, average hearing loss and high frequency hearing loss) are highly inter-connected in both networks with sound sensitivity and loudness discomfort level being highly influential with high measures of centrality. Furthermore, the relationship between the densely connected auditory subnetwork with tinnitus-related distress seems to vary at different levels of distress, hearing loss, duration and age of the participants.

CONCLUSION

Our findings provide first-time evidence for tinnitus varying in a dimensional fashion illustrating the heterogeneity of this phantom percept and its ability to be perceptually integrated, yet behaviourally segregated on different symptomatic dimensions.

Prevalence of Hyperacusis Diagnosis in Veterans Who Use VA Healthcare

OBJECTIVES

The primary objective was to estimate the prevalence of hyperacusis diagnosis in treatment-seeking Veterans, paying attention to when it is diagnosed in conjuncture with common comorbid conditions.

DESIGN

This retrospective observational study used Veteran electronic health records from January 2015 to July 2021. Hyperacusis and comorbid conditions were identified using International Classification of Disease diagnostic codes.

RESULTS

The prevalence of hyperacusis diagnosis was 0.06%. Veterans diagnosed with tinnitus, posttraumatic stress disorder, headache, or traumatic brain injury were between two and seven times more likely to have an International Classification of Disease code for hyperacusis.

CONCLUSIONS

The estimated prevalence of hyperacusis diagnosis using electronic health records is grossly below what is reported in the literature. This is likely due to lack of standardized methods to diagnosis hyperacusis and when present with comorbid conditions, uncertainty when it should be coded as a secondary diagnosis. Future clinical and research efforts prioritizing hyperacusis are desperately needed.

Cognitive Screening and Hearing Assessment in Patients With Chronic Tinnitus

OBJECTIVES

The study aimed to assess the relationship of tinnitus with hyperacusis with cognitive impairment as indicated by the Montreal Cognitive Assessment (MoCA) tool.

METHODS

This multicenter cross-sectional study included individuals with chronic tinnitus from the "Unification of Treatments and Interventions for Tinnitus Patients" (UNITI) database. Participants were recruited from four different tertiary clinical centers located in Athens and Granada (Mediterranean group), as well as Berlin and Regensburg (German group). In total, 380 individuals with a diagnosis of non-pulsatile chronic tinnitus (permanent and constant tinnitus lasting more than 6 months) and no evidence of severe cognitive impairment (MoCA score >22) were enrolled. The evaluation utilized the following tools: MoCA, Tinnitus Handicap Inventory (THI), Hyperacusis Questionnaire (GÜF), Patient Health Questionnaire (PHQ-9), and the European School for Interdisciplinary Tinnitus Research Screening Questionnaire.

RESULTS

MoCA scores differed between German and Mediterranean individuals (P<0.01), necessitating separate analyses for each group. In both cohorts, MoCA scores were significantly associated with education level, age, hearing threshold at 8 kHz, and THI. Furthermore, a significant correlation was observed between PHQ-9 scores and both THI and GÜF (P<0.01 for both Germans and those from the Mediterranean).

CONCLUSION

Our data suggest an association between tinnitus handicap, high-frequency hearing loss, and mild cognitive impairment. Additionally, PHQ-9 scores were associated with tinnitus and hyperacusis scores, independent of hearing loss thresholds.

A Systematic Review on the Genetic Contribution to Tinnitus

PURPOSE

To assess the available evidence to support a genetic contribution and define the role of common and rare variants in tinnitus.

METHODS

After a systematic search and quality assessment, 31 records including 383,063 patients were selected (14 epidemiological studies and 17 genetic association studies). General information on the sample size, age, sex, tinnitus prevalence, severe tinnitus distribution, and sensorineural hearing loss was retrieved. Studies that did not include data on hearing assessment were excluded. Relative frequencies were used for qualitative variables to compare different studies and to obtain average values. Genetic variants and genes were listed and clustered according to their potential role in tinnitus development.

RESULTS

The average prevalence of tinnitus estimated from population-based studies was 26.3% for any tinnitus, and 20% of patients with tinnitus reported it as an annoying symptom. One study has reported population-specific differences in the prevalence of tinnitus, the white ancestry being the population with a higher prevalence. Genome-wide association studies have identified and replicated two common variants in the Chinese population (rs2846071; rs4149577) in the intron of TNFRSF1A, associated with noise-induced tinnitus. Moreover, gene burden analyses in sequencing data from Spanish and Swede patients with severe tinnitus have identified and replicated ANK2, AKAP9, and TSC2 genes.

CONCLUSIONS

The genetic contribution to tinnitus is starting to be revealed and it shows population-specific effects in European and Asian populations. The common allelic variants associated with tinnitus that showed replication are associated with noise-induced tinnitus. Although severe tinnitus has been associated with rare variants with large effect, their role on hearing or hyperacusis has not been established.

Genetic architecture distinguishes tinnitus from hearing loss

Tinnitus is a heritable, highly prevalent auditory disorder treated by multiple medical specialties. Previous GWAS indicated high genetic correlations between tinnitus and hearing loss, with little indication of differentiating signals. We present a GWAS meta-analysis, triple previous sample sizes, and expand to non-European ancestries. GWAS in 596,905 Million Veteran Program subjects identified 39 tinnitus loci, and identified genes related to neuronal synapses and cochlear structural support. Applying state-of-the-art analytic tools, we confirm a large number of shared variants, but also a distinct genetic architecture of tinnitus, with higher polygenicity and large proportion of variants not shared with hearing difficulty. Tissue-expression analysis for tinnitus infers broad enrichment across most brain tissues, in contrast to hearing difficulty. Finally, tinnitus is not only correlated with hearing loss, but also with a spectrum of psychiatric disorders, providing potential new avenues for treatment. This study establishes tinnitus as a distinct disorder separate from hearing difficulties.

Differential cortical activation patterns: pioneering sub-classification of tinnitus with and without hyperacusis by combining audiometry, gamma oscillations, and hemodynamics

The ongoing controversies about the neural basis of tinnitus, whether linked with central neural gain or not, may hamper efforts to develop therapies. We asked to what extent measurable audiometric characteristics of tinnitus without (T) or with co-occurrence of hyperacusis (TH) are distinguishable on the level of cortical responses. To accomplish this, electroencephalography (EEG) and concurrent functional near-infrared spectroscopy (fNIRS) were measured while patients performed an attentionally demanding auditory discrimination task using stimuli within the individual tinnitus frequency (fTin) and a reference frequency (fRef). Resting-state-fMRI-based functional connectivity (rs-fMRI-bfc) in ascending auditory nuclei (AAN), the primary auditory cortex (AC-I), and four other regions relevant for directing attention or regulating distress in temporal, parietal, and prefrontal cortex was compiled and compared to EEG and concurrent fNIRS activity in the same brain areas. We observed no group differences in pure-tone audiometry (PTA) between 10 and 16 kHz. However, the PTA threshold around the tinnitus pitch was positively correlated with the self-rated tinnitus loudness and also correlated with distress in T-groups, while TH experienced their tinnitus loudness at minimal loudness levels already with maximal suffering scores. The T-group exhibited prolonged auditory brain stem (ABR) wave I latency and reduced ABR wave V amplitudes (indicating reduced neural synchrony in the brainstem), which were associated with lower rs-fMRI-bfc between AAN and the AC-I, as observed in previous studies. In T-subjects, these features were linked with elevated spontaneous and reduced evoked gamma oscillations and with reduced deoxygenated hemoglobin (deoxy-Hb) concentrations in response to stimulation with lower frequencies in temporal cortex (Brodmann area (BA) 41, 42, 22), implying less synchronous auditory responses during active auditory discrimination of reference frequencies. In contrast, in the TH-group gamma oscillations and hemodynamic responses in temporoparietal regions were reversed during active discrimination of tinnitus frequencies. Our findings suggest that T and TH differ in auditory discrimination and memory-dependent directed attention during active discrimination at either tinnitus or reference frequencies, offering a test paradigm that may allow for more precise sub-classification of tinnitus and future improved treatment approaches.

Predictive coding and stochastic resonance as fundamental principles of auditory phantom perception

Mechanistic insight is achieved only when experiments are employed to test formal or computational models. Furthermore, in analogy to lesion studies, phantom perception may serve as a vehicle to understand the fundamental processing principles underlying healthy auditory perception. With a special focus on tinnitus-as the prime example of auditory phantom perception-we review recent work at the intersection of artificial intelligence, psychology and neuroscience. In particular, we discuss why everyone with tinnitus suffers from (at least hidden) hearing loss, but not everyone with hearing loss suffers from tinnitus. We argue that intrinsic neural noise is generated and amplified along the auditory pathway as a compensatory mechanism to restore normal hearing based on adaptive stochastic resonance. The neural noise increase can then be misinterpreted as auditory input and perceived as tinnitus. This mechanism can be formalized in the Bayesian brain framework, where the percept (posterior) assimilates a prior prediction (brain's expectations) and likelihood (bottom-up neural signal). A higher mean and lower variance (i.e. enhanced precision) of the likelihood shifts the posterior, evincing a misinterpretation of sensory evidence, which may be further confounded by plastic changes in the brain that underwrite prior predictions. Hence, two fundamental processing principles provide the most explanatory power for the emergence of auditory phantom perceptions: predictive coding as a top-down and adaptive stochastic resonance as a complementary bottom-up mechanism. We conclude that both principles also play a crucial role in healthy auditory perception. Finally, in the context of neuroscience-inspired artificial intelligence, both processing principles may serve to improve contemporary machine learning techniques.

Review and Perspective on Brain Bases of Tinnitus

In advancing our understanding of tinnitus, some of the more impactful contributions in the past two decades have come from human brain imaging studies, specifically the idea of both auditory and extra-auditory neural networks that mediate tinnitus. These networks subserve both the perception of tinnitus and the psychological reaction to chronic, continuous tinnitus. In this article, we review particular studies that report on the nodes and links of such neural networks and their inter-network connections. Innovative neuroimaging tools have contributed significantly to the increased understanding of anatomical and functional connections of attention, emotion-processing, and default mode networks in adults with tinnitus. We differentiate between the neural correlates of tinnitus and those of comorbid hearing loss; surprisingly, tinnitus and hearing loss when they co-occur are not necessarily additive in their impact and, in rare cases, additional tinnitus may act to mitigate the consequences of hearing loss alone on the brain. The scale of tinnitus severity also appears to have an impact on brain networks, with some of the alterations typically attributed to tinnitus reaching significance only in the case of bothersome tinnitus. As we learn more about comorbid conditions of tinnitus, such as depression, anxiety, hyperacusis, or even aging, their contributions to the network-level changes observed in tinnitus will need to be parsed out in a manner similar to what is currently being done for hearing loss or severity. Together, such studies advance our understanding of the heterogeneity of tinnitus and will lead to individualized treatment plans.

Screening for Circulating Inflammatory Proteins Does Not Reveal Plasma Biomarkers of Constant Tinnitus

BACKGROUND AND OBJECTIVE

Tinnitus would benefit from an objective biomarker. The goal of this study is to identify plasma biomarkers of constant and chronic tinnitus among selected circulating inflammatory proteins.

METHODS

A case-control retrospective study on 548 cases with constant tinnitus and 548 matched controls from the Swedish Tinnitus Outreach Project (STOP), whose plasma samples were examined using Olink's Inflammatory panel. Replication and meta-analysis were performed using the same method on samples from the TwinsUK cohort. Participants from LifeGene, whose blood was collected in Stockholm and Umeå, were recruited to STOP for a tinnitus subtyping study. An age and sex matching was performed at the individual level. TwinsUK participants (n = 928) were selected based on self-reported tinnitus status over 2 to 10 years. Primary outcomes include normalized levels for 96 circulating proteins, which were used as an index test. No reference standard was available in this study.

RESULTS

After adjustment for age, sex, BMI, smoking, hearing loss, and laboratory site, the top proteins identified were FGF-21, MCP4, GDNF, CXCL9, and MCP-1; however, these were no longer statistically significant after correction for multiple testing. Stratification by sex did not yield any significant associations. Similarly, associations with hearing loss or other tinnitus-related comorbidities such as stress, anxiety, depression, hyperacusis, temporomandibular joint disorders, and headache did not yield any significant associations. Analysis in the TwinsUK failed in replicating the top candidates. Meta-analysis of STOP and TwinsUK did not reveal any significant association. Using elastic net regularization, models exhibited poor predictive capacity tinnitus based on inflammatory markers [sensitivity = 0.52 (95% CI 0.47-0.57), specificity = 0.53 (0.48-0.58), positive predictive value = 0.52 (0.47-0.56), negative predictive values = 0.53 (0.49-0.58), and AUC = 0.53 (0.49-0.56)].

DISCUSSION

Our results did not identify significant associations of the selected inflammatory proteins with constant tinnitus. Future studies examining longitudinal relations among those with more severe tinnitus and using more recent expanded proteomics platforms and sampling of cerebrospinal fluid could increase the likelihood of identifying relevant molecular biomarkers.

Hyperacusis: Focus on Gender Differences: A Systematic Review

BACKGROUND

While gender differences of several diseases have been already described in the literature, studies in the area of hyperacusis are still scant. Despite the fact that hyperacusis is a condition that severely affects the patient's quality of life, it is not well investigated; a comprehensive understanding of its features, eventually including gender differences, could be a valuable asset in developing clinical intervention strategies.

AIM

To evaluate gender differences among subjects affected by hyperacusis.

METHODS

A literature search was conducted focused on adult patients presenting hyperacusis, using the MedLine bibliographic database. Relevant peer-reviewed studies, published in the last 20 years, were sought. A total of 259 papers have been identified, but only 4 met the inclusion criteria. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

The four selected papers included data from 604 patients; of these, 282 subjects resulted as affected by hyperacusis (125 females and 157 males). Questionnaires for analyzing factors affecting the attentional, social and emotional variance of hyperacusis (such as VAS, THI, TSCH, MASH) were administered to all included subjects. The data suggest that there are no hyperacusis gender-specific differences in the assessed population samples.

CONCLUSIONS

The literature data suggest that males and females exhibit a similar level of hyperacusis. However, in light of the subjective nature of this condition, the eventual set up of further tests to assess hyperacusis features could be very helpful in the near future.

Hyperacusis Assessment Questionnaire-A New Tool Assessing Hyperacusis in Subjects with Tinnitus

Hyperacusis, a kind of decreased sound tolerance, is difficult to measure objectively. It often co-occurs with tinnitus. There is a need for valid and reliable patient-reported outcome measures to capture this subjective phenomenon. The aim of the study was to create a questionnaire capturing hyperacusis in terms of loudness, fear, and pain and to evaluate its psychometric properties. The study sample consisted of 106 adult patients with hyperacusis and tinnitus with a mean age of 45.2 years. A medical interview, an audiological examination, and several questionnaires (the Tinnitus Handicap Inventory, the Hyperacusis Questionnaire, the State-Trait Anxiety Inventory, and Visual Analog Scales) were applied. The final 14-item Hyperacusis Assessment Questionnaire showed an appropriate three-factor structure with 70.5% of the variance explained. Convergent and divergent validity were confirmed by correlations with other measures of hyperacusis, anxiety, tinnitus severity, misophonia, and hearing thresholds. The internal consistency assessed with Cronbach's alpha was excellent (α = 0.91), as was reproducibility (intraclass correlation, ICC = 0.96). The new Hyperacusis Assessment Questionnaire is a psychometrically sound and brief tool assessing the severity of hyperacusis in terms of loudness, fear, and pain. It can be used in clinical practice and scientific research for patients with hyperacusis and tinnitus.

Young Adults' Knowledge and Perceptions of Permanent Noise-Induced Tinnitus and its Influence on Behavioural Intentions

Objective

Young adults' music-listening behaviours may put them at risk of developing permanent hearing loss and tinnitus. This study aimed to assess knowledge of permanent tinnitus and whether this knowledge may influence listening behaviours to a greater degree than knowledge of hearing loss.

Materials and Methods

A two-group (between subjects), randomised post-test only, single-factor experimental design was used to determine the effects of health message focus (permanent tinnitus vs. permanent hearing loss) on the main outcome measure of protective behavioural intention. The sample included 109 male and 287 female adults, aged 18 to 25 years, living in the United Kingdom. The young adults' existing knowledge of either permanent hearing loss or permanent tinnitus was measured, and after exposure to a health message, their perceptions and resultant behavioural intentions were assessed and compared. The pooled data were used to test a proposed model of factors influencing hearing protective behavioural intention using path analysis.

Results

Whilst 83% knew about the link with hearing loss, only 75% knew that loud music may cause permanent tinnitus. The participants viewed tinnitus as closer temporally than hearing loss, perceived themselves as equally susceptible to both, but perceived hearing loss as more severe. There was no significant difference in behavioural intention between the groups.

Conclusion

Perceived susceptibility and severity have a positive effect on behavioural intentions. In light of these results, recommendations for future noise-damage prevention campaigns are made.

Nuances in intensity deviant asymmetric responses as a biomarker for tinnitus

We attempted to replicate a potential tinnitus biomarker in humans based on the Sensory Precision Integrative Model of Tinnitus called the Intensity Mismatch Asymmetry. A few advances on the design were also included, including tighter matching of participants for gender, and a control stimulus frequency of 1 kHz to investigate whether any differences between control and tinnitus groups are specific to the tinnitus frequency or domain-general. The expectation was that there would be asymmetry in the MMN responses between tinnitus and control groups at the tinnitus frequency, but not at the control frequency, where the tinnitus group would have larger, more negative responses to upward deviants than downward deviants, and the control group would have the opposite pattern or lack of a deviant direction effect. However, no significant group differences were found. There was a striking difference in response amplitude to control frequency stimuli compared to tinnitus frequency stimuli, which could be an intrinsic quality of responses to these frequencies or could reflect high frequency hearing loss in the sample. Additionally, the upward deviants elicited stronger MMN responses in both groups at tinnitus frequency, but not at the control frequency. Factors contributing to these discrepant results at the tinnitus frequency could include hyperacusis, attention, and wider contextual effects of other frequencies used in the experiment (i.e. the control frequency in other blocks).

Listening Effort in Tinnitus: A Pilot Study Employing a Light EEG Headset and Skin Conductance Assessment during the Listening to a Continuous Speech Stimulus under Different SNR Conditions

Background noise elicits listening effort. What else is tinnitus if not an endogenous background noise? From such reasoning, we hypothesized the occurrence of increased listening effort in tinnitus patients during listening tasks. Such a hypothesis was tested by investigating some indices of listening effort through electroencephalographic and skin conductance, particularly parietal and frontal alpha and electrodermal activity (EDA). Furthermore, tinnitus distress questionnaires (THI and TQ12-I) were employed. Parietal alpha values were positively correlated to TQ12-I scores, and both were negatively correlated to EDA; Pre-stimulus frontal alpha correlated with the THI score in our pilot study; finally, results showed a general trend of increased frontal alpha activity in the tinnitus group in comparison to the control group. Parietal alpha during the listening to stimuli, positively correlated to the TQ12-I, appears to reflect a higher listening effort in tinnitus patients and the perception of tinnitus symptoms. The negative correlation between both listening effort (parietal alpha) and tinnitus symptoms perception (TQ12-I scores) with EDA levels could be explained by a less responsive sympathetic nervous system to prepare the body to expend increased energy during the "fight or flight" response, due to pauperization of energy from tinnitus perception.

Hyperacusis is associated with smaller gray matter volumes in the supplementary motor area

Hyperacusis is a disorder in loudness perception characterized by increased sensitivity to ordinary environmental sounds and associated with otologic conditions, including hearing loss and tinnitus (the phantom perception of sound) as well as neurologic and neuropsychiatric conditions. Hyperacusis is believed to arise centrally in the brain; however, the underlying causes are unknown. To gain insight into differences in brain morphology associated with hyperacusis, we undertook a retrospective case-control study comparing whole-brain gray matter morphology in participants with sensorineural hearing loss and tinnitus who either scored above or below the threshold for hyperacusis based on a standard questionnaire. We found that participants reporting hyperacusis had smaller gray matter volumes and cortical sheet thicknesses in the right supplementary motor area (SMA), independent of anxiety, depression, tinnitus burden, or sex. In fact, the right SMA volumes extracted from an independently defined volume of interest could accurately classify participants. Finally, in a subset of participants where functional data were also available, we found that individuals with hyperacusis showed increased sound-evoked responses in the right SMA compared to individuals without hyperacusis. Given the role of the SMA in initiating motion, these results suggest that in hyperacusis the SMA is involved in a motor response to sounds.

Validity and reliability study of the Khalfa's hyperacusis questionnaire with using ULL in tinnitus patients

PURPOSE

This study aims to investigate the validity and reliability of the Khalfa's hyperacusis questionnaire (HQ) in Turkish tinnitus patients with hyperacusis using uncomfortable loudness levels (ULLs) and to determine a cutoff score for tinnitus patients specifically.

MATERIALS AND METHODS

One hundred and forty subjects with a mean age ± SD of 45.27 ± 14.43 years ranging from 18 to 75 participated in the study. HQ and ULLs were used as measures of hyperacusis. The participants were divided into two groups due to ULLs ≤ 90 dB in one or both ears (Group 1) and 56 participants have ULLs > 90 dB (Group 2).

RESULTS

The mean HQ score of the participants was 19.55 ± 7.18 points, Group 1 (n = 84) HQ mean score was 21.97 ± 7.08, and Group 2 (n = 56) 15.91 ± 5.56 points, and the cutoff point was found 16.50. Statistically significant differences were found between the groups in total HQ (p < 0.001), attention, social, and emotional subscales of HQ.

CONCLUSIONS

Hyperacusis questionnaire using with ULLs is a precise tool for the steps of identifying, categorizing, and managing the hyperacusis in patients with tinnitus. However, the effect of the tinnitus on hyperacusis should be considered, because it causes additional problems.

Low Evidence for Tinnitus Risk Factors: A Systematic Review and Meta-analysis

AIMS/HYPOTHESIS

Identifying risk factors for tinnitus could facilitate not only the recommendations for prevention measures, but also identifying potential pathways for new interventions. This study reports the first comprehensive systematic review of analytical observational studies able to provide information about causality (i.e., case-control and cohort designs).

METHODS

A literature search of four electronic databases identified epidemiological studies published on tinnitus and different exposures. Independent raters screened all studies, extracted data, and evaluated study quality using the Newcastle-Ottawa Scale. Reported relative risks (RR), hazard ratios (HR), odds ratios (OR), and prevalence ratios (PR) with 95% confidence intervals (CI) were used to compute crude estimates of RR for tinnitus risk factors.

RESULTS

From 2389 records identified, a total of 374 articles were read as full text (24 reviews, 301 cross-sectional studies, 42 cohort studies, and 7 case-control studies). However, from 49 case-control and cohort studies, only 25 adequately reported risk ratios. Using the findings from these studies, positive causal associations were found for various hearing-related factors (i.e., unspecified hearing loss, sensorineural hearing loss, occupational noise exposure, ototoxic platinum therapy, and otitis media). Evidence was also found for a number of non-otological risk factors including temporo-mandibular joint disorder, depression, chronic obstructive pulmonary disease, and hyperlipidemia. Negative associations indicating preventative effects were found for diabetes and high alcohol consumption. No associations were found for low alcohol consumption, body mass index, head injury, heart failure, hypertension, leisure noise exposure, migraine, rheumatoid arthritis, sex, smoking, stroke, and whiplash. However, with the exception of unspecified hearing loss, these findings resulted from pooling no more than 4 studies, illustrating that the vast majority of the associations still remain inconclusive.

CONCLUSIONS

These systematic review and meta-analysis confirm a number of otological and non-otological risk factors for tinnitus. By highlighting major gaps in knowledge, our synthesis can help provide direction for future research that will shed light on the pathophysiology, improve management strategies, and inform more effective preventions.

Using coding and non-coding rare variants to target candidate genes in patients with severe tinnitus

Tinnitus is the phantom percept of an internal non-verbal set of noises and tones. It is reported by 15% of the population and it is usually associated with hearing and/or brain disorders. The role of structural variants (SVs) in coding and non-coding regions has not been investigated in patients with severe tinnitus. In this study, we performed whole-genome sequencing in 97 unrelated Swedish individuals with chronic tinnitus (TIGER cohort). Rare single nucleotide variants (SNV), large structural variants (LSV), and copy number variations (CNV) were retrieved to perform a gene enrichment analysis in TIGER and in a subgroup of patients with severe tinnitus (SEVTIN, n = 34), according to the tinnitus handicap inventory (THI) scores. An independent exome sequencing dataset of 147 Swedish tinnitus patients was used as a replication cohort (JAGUAR cohort) and population-specific datasets from Sweden (SweGen) and Non-Finish Europeans (NFE) from gnomAD were used as control groups. SEVTIN patients showed a higher prevalence of hyperacusis, hearing loss, and anxiety when they were compared to individuals in the TIGER cohort. We found an enrichment of rare missense variants in 6 and 8 high-constraint genes in SEVTIN and TIGER cohorts, respectively. Of note, an enrichment of missense variants was found in the CACNA1E gene in both SEVTIN and TIGER. We replicated the burden of missense variants in 9 high-constrained genes in the JAGUAR cohort, including the gene NAV2, when data were compared with NFE. Moreover, LSVs in constrained regions overlapping CACNA1E, NAV2, and TMEM132D genes were observed in TIGER and SEVTIN.

Clinical Findings That Differentiate Co-Occurrence of Hyperacusis and Tinnitus from Tinnitus Alone

PURPOSE

We aimed to assess the characteristics of patients with concurrent tinnitus and hyperacusis, determine the best audiological criteria for predicting hyperacusis, and confirm whether objective evidence of changes in the brain exists.

MATERIALS AND METHODS

The medical records of patients with tinnitus who visited the hospital between March 2020 and December 2021 were reviewed. Data on accompanying hyperacusis, audiological profiles, and questionnaires including the Tinnitus Handicap Inventory (THI), Beck Depression Inventory, and numerical rating scale were analyzed. Resting-state quantitative electroencephalography (qEEG) using power spectral density (PSD) and event-related spectral perturbation (ERSP) were performed to objectively quantify changes in the brain.

RESULTS

A total of 194 patients were analyzed. Among them, 51 (26.3%) reported combined subjective hyperacusis with tinnitus. However, the proportions widely varied from 7.4% to 68.4% based on three audiological criteria for assessment. A higher score on the THI questionnaire was independently associated with the co-occurrence of tinnitus and hyperacusis. Fair agreement was observed between subjective hyperacusis and the audiological criterion based on a loudness discomfort level (LDL) of ≤90 dB at two or more frequencies for the diagnosis of hyperacusis. An increased beta-PSD and decreased levels of gamma-PSD, all-ERSP, and delta-ERSP were observed in patients with hyperacusis (p<0.05).

CONCLUSION

Patients with co-occurring tinnitus and hyperacusis had more severe tinnitus distress. An LDL of ≤90 dB at two or more frequencies may be applicable to predict accompanying hyperacusis in subjects with tinnitus, and qEEG also provides more objective information.

The DizzyQuest: relation between self-reported hearing loss, tinnitus and objective hearing thresholds in patients with Meniere's disease

BACKGROUND

Combining a mobile application-based vestibular diary called the DizzyQuest and an iPad-based hearing test enables evaluation of the relationship between experienced neuro-otological symptoms and hearing thresholds in daily life setting. The aim was to investigate the relationship between self-reported hearing symptoms and hearing thresholds in patients with Meniere's disease (MD), using the DizzyQuest and the iPad-based hearing test simultaneously.

METHODS

The DizzyQuest was administered for 3 weeks in 21 patients. Using the experience-sampling-method (ESM), it assessed hearing loss and tinnitus severity for both ears separately. Each day after the DizzyQuest, an iPad-based hearing test was used to measure hearing thresholds. A mixed model regression analysis was performed to investigate relationships between hearing thresholds and self-reported hearing loss and tinnitus severity.

RESULTS

Fifteen patients were included. Overall, pure-tone averages (PTAs) were not correlated with self-reported hearing loss severity and tinnitus. Individual differences in PTA results between both ears did not significantly influence the difference in self-reported hearing loss severity between both ears. Self-reported hearing loss and tinnitus scores were significantly higher in ears that corresponded with audiometric criteria of MD (p < 0.001). Self-reported tinnitus severity significantly increased with self-reported hearing loss severity in affected (p = 0.011) and unaffected ears (p < 0.001).

CONCLUSION

Combining the DizzyQuest and iPad-based hearing test, facilitated assessment of self-reported hearing loss and tinnitus severity and their relationship with hearing thresholds, in a daily life setting. This study illustrated the importance of investigating neuro-otological symptoms at an individual level, using multiple measurements. ESM strategies like the DizzyQuest should therefore be considered in neuro-otological research.

Neural signatures of auditory hypersensitivity following acoustic trauma

Neurons in sensory cortex exhibit a remarkable capacity to maintain stable firing rates despite large fluctuations in afferent activity levels. However, sudden peripheral deafferentation in adulthood can trigger an excessive, non-homeostatic cortical compensatory response that may underlie perceptual disorders including sensory hypersensitivity, phantom limb pain, and tinnitus. Here, we show that mice with noise-induced damage of the high-frequency cochlear base were behaviorally hypersensitive to spared mid-frequency tones and to direct optogenetic stimulation of auditory thalamocortical neurons. Chronic two-photon calcium imaging from ACtx pyramidal neurons (PyrNs) revealed an initial stage of spatially diffuse hyperactivity, hyper-correlation, and auditory hyperresponsivity that consolidated around deafferented map regions three or more days after acoustic trauma. Deafferented PyrN ensembles also displayed hypersensitive decoding of spared mid-frequency tones that mirrored behavioral hypersensitivity, suggesting that non-homeostatic regulation of cortical sound intensity coding following sensorineural loss may be an underlying source of auditory hypersensitivity. Excess cortical response gain after acoustic trauma was expressed heterogeneously among individual PyrNs, yet 40% of this variability could be accounted for by each cell's baseline response properties prior to acoustic trauma. PyrNs with initially high spontaneous activity and gradual monotonic intensity growth functions were more likely to exhibit non-homeostatic excess gain after acoustic trauma. This suggests that while cortical gain changes are triggered by reduced bottom-up afferent input, their subsequent stabilization is also shaped by their local circuit milieu, where indicators of reduced inhibition can presage pathological hyperactivity following sensorineural hearing loss.

The Short and Long-Term Effect of Sound Therapy on Visual Attention in Chronic Tinnitus Patients

Sound therapy is one of the most common tinnitus treatments that can be used either to mask or to shift attention away from the tinnitus percept. However, the actual benefit of sound therapy and the mechanisms leading to the benefits remain limited. The objective of this study was to investigate the short-term (15 min) and long-term (2 months) effects of sound therapy on visual attention in chronic tinnitus patients. Visual attention was evaluated with the behavioral Attention Network Task, while the tinnitus-related distress was evaluated with the Tinnitus Handicap Inventory (THI) to quantify the effect of sound therapy. The study included 20 participants with chronic and bothersome tinnitus (>6 months, THI > 18) and 20 matched control participants. All participants took part in a first session consisting of a baseline condition, a short-term sound therapy condition and a silent control condition. The tinnitus participants also took part in a second session that evaluated the long-term effect of the therapy. A reduction in the tinnitus-related distress was found after the long-term use of sound therapy. Furthermore, a reduction in the differential index of the executive control (EC) attention network, indicating improved attention, was found after long-term use of sound therapy in the sound condition but not in the silent control condition. In contrast to earlier research, no differences were found between the tinnitus group and the control group for the baseline measurement of the EC attention network. Overall, the results suggest that there is no link between the visual attention networks and the sound therapy’s effect on tinnitus-related distress.

Sound Tolerance Conditions (Hyperacusis, Misophonia, Noise Sensitivity, and Phonophobia): Definitions and Clinical Management

Purpose: For some people, exposure to everyday sounds presents a significant problem. The purpose of this tutorial was to define and differentiate between the various sound tolerance conditions and to review some options for their clinical management.

METHOD

We informally reviewed the literature regarding sound tolerance conditions. The terminology and definitions provided are mostly consistent with how these terms are defined. However, many inconsistencies are noted. Methods of assessment and treatment also differ, and different methodologies are briefly described.

RESULTS

Hyperacusis describes physical discomfort or pain when any sound reaches a certain level of loudness that would be tolerable for most people. Misophonia refers to intense emotional reactions to certain sounds (often body sounds such as chewing and sniffing) that are not influenced by the perceived loudness of those sounds. Noise sensitivity refers to increased reactivity to sounds that may include general discomfort (annoyance or feeling overwhelmed) due to a perceived noisy environment, regardless of its loudness. Phonophobia, as addressed in the audiology profession, describes anticipatory fear of sound. Phonophobia is an emotional response such as anxiety and avoidance of sound due to the "fear" that sound(s) may occur that will cause a comorbid condition to get worse (e.g., tinnitus) or the sound itself will result in discomfort or pain. (Note that phonophobia is a term used by neurologists to describe "migraineur phonophobia"-a different condition not addressed herein.) Conclusions: The literature addresses sound tolerance conditions but reveals many inconsistencies, indicating lack of consensus in the field. When doing an assessment for decreased sound tolerance, it is important to define any terms used so that the patient and all health care professionals involved in the care of the patient are aligned with the goals of the treatment plan. Treatment generally involves gradual and systematic sound desensitization and counseling.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20164130.

Global Prevalence and Incidence of Tinnitus: A Systematic Review and Meta-analysis

Importance

To date, no systematic review has taken a meta-analytic approach to estimating the prevalence and incidence of tinnitus in the general population.

Objective

To provide frequency estimates of tinnitus worldwide.

Data Sources

An umbrella review followed by a traditional systematic review was performed by searching PubMed-MEDLINE and Embase from inception through November 19, 2021.

Study Selection

Research data from the general population were selected, and studies based on patients or on subgroups of the population with selected lifestyle habits were excluded. No restrictions were applied according to date, age, sex, and country.

Data Extraction and Synthesis

Relevant extracted information included type of study, time and location, end point, population characteristics, and tinnitus definition. The study followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline.

Main Outcomes and Measures

Pooled prevalence estimates of any tinnitus, severe tinnitus, chronic tinnitus, and diagnosed tinnitus as well as incidence of tinnitus were obtained using random-effects meta-analytic models; heterogeneity between studies was controlled using the χ2 test, and inconsistency was measured using the I2 statistic.

Results

Among 767 publications, 113 eligible articles published between 1972 and 2021 were identified, and prevalence estimates from 83 articles and incidence estimates from 12 articles were extracted. The pooled prevalence of any tinnitus among adults was 14.4% (95% CI, 12.6%-16.5%) and ranged from 4.1% (95% CI, 3.7%-4.4%) to 37.2% (95% CI, 34.6%-39.9%). Prevalence estimates did not significantly differ by sex (14.1% [95% CI, 11.6%-17.0%] among male individuals; 13.1% [95% CI, 10.5%-16.2%] among female individuals), but increased prevalence was associated with age (9.7% [95% CI, 7.4%-12.5%] among adults aged 18-44 years; 13.7% [95% CI, 11.0%-17.0%] among those aged 45-64 years; and 23.6% [95% CI, 19.4%-28.5%] among those aged ≥65 years; P < .001 among age groups). The pooled prevalence of severe tinnitus was 2.3% (95% CI, 1.7%-3.1%), ranging from 0.5% (95% CI, 0.3%-0.7%) to 12.6% (95% CI, 11.1%-14.1%). The pooled prevalence of chronic tinnitus was 9.8% (95% CI, 4.7%-19.3%) and the pooled prevalence of diagnosed tinnitus was 3.4% (95% CI, 2.1%-5.5%). The pooled incidence rate of any tinnitus was 1164 per 100 000 person-years (95% CI, 479-2828 per 100 000 person-years).

Conclusions and Relevance

Despite the substantial heterogeneity among studies, this comprehensive systematic review on the prevalence and incidence of tinnitus suggests that tinnitus affects more than 740 million adults globally and is perceived as a major problem by more than 120 million people, mostly aged 65 years or older. Health policy makers should consider the global burden of tinnitus, and greater effort should be devoted to boost research on tinnitus.

Associations between Demographics, Tinnitus Specific-, Audiological-, General- and Mental Health Factors, and the Impact of Tinnitus on Daily Life

Our objective was to study associations between demographics, tinnitus specific-, audiological-, general- and mental health characteristics, and impact of tinnitus in the general population. In this cross-sectional survey study in the Dutch population, data were prospectively gathered. Tinnitus impact was assessed with the Tinnitus Functional Index (TFI). We included participants who experienced tinnitus and for whom a total TFI score could be calculated (n = 212). We performed univariable and multivariable regression analyses. Due to logarithmical transformation, the B-scores were back-transformed to show the actual difference in points on the TFI. People who considered hyperacusis a small problem had a 12.5-point higher TFI score, those who considered it a mediocre problem had a 17.6-point higher TFI score and those who considered it a large problem had a 24.1-point higher TFI score compared to people who did not consider hyperacusis a problem. People who indicated having minor hearing problems had a 10.5-point higher TFI score, those with mediocre hearing problems had a 20.4-point higher TFI score and those with severe hearing problems had a 41.6-point higher TFI score compared to people who did not have subjective hearing problems. In conclusion, audiological risk factors, such as hearing problems and hyperacusis, have the largest association with the impact of tinnitus on daily life, compared to other assessed variables. The results of this study can be used in future research to find targeted interventions to diminish the impact of tinnitus.

Psychometric Evaluation of the Hyperacusis Impact Questionnaire (HIQ) and Sound Sensitivity Symptoms Questionnaire (SSSQ) Using a Clinical Population of Adult Patients with Tinnitus Alone or Combined with Hyperacusis

BACKGROUND

Hyperacusis can be defined as an intolerance of certain everyday sounds, which are perceived as too loud or uncomfortable and which cause significant distress and impairment in the individual's day-to-day activities. It is important to assess symptoms of sound intolerance and their impact on the patient's life, so as to evaluate the need for treatment and to assess the effectiveness of treatments.

PURPOSE

The aim was to evaluate the psychometric properties of the Hyperacusis Impact Questionnaire (HIQ), and the Sound Sensitivity Symptoms Questionnaire (SSSQ). The 8-item HIQ focuses on assessing the impact of hyperacusis on the patient, while the 5-item SSSQ is designed to assess the type and severity of sound intolerance symptoms.

RESEARCH DESIGN

This was a retrospective cross-sectional study.

STUDY SAMPLE

In total, 266 consecutive patients who attended a Tinnitus and Hyperacusis Therapy Clinic in the United Kingdom within a 6-month period. Fifty-five percent were female. The average age was 54 years (standard deviation = 16 years).

DATA COLLECTION AND ANALYSIS

Data were collected retrospectively from the records of patients held at the audiology department. Audiological measures were pure-tone audiometry and Uncomfortable Loudness Levels (ULLs). Questionnaires administered in addition to the HIQ and SSSQ were: Tinnitus Handicap Inventory, Hyperacusis Questionnaire (HQ), and Screening for Anxiety and Depression in Tinnitus.

RESULTS

Exploratory factor analysis suggested one-factor solutions for both the HIQ and SSSQ. Multiple-causes multiple-indicators (MIMIC) models showed some small influences of gender but negligible effects of age for both the HIQ and SSSQ. Receiver Operating Characteristic (ROC) analysis showed no significant effects of covariates on the ROC curves. Cronbach's α was 0.93 for the HIQ, and 0.87 for the SSSQ, indicating high internal consistency. Convergent validity was supported by moderate correlations between HQ and HIQ scores and between SSSQ scores and ULLs.

CONCLUSION

The HIQ and SSSQ are internally consistent questionnaires that can be used in clinical and research settings.

Audiological and Other Factors Predicting the Presence of Misophonia Symptoms Among a Clinical Population Seeking Help for Tinnitus and/or Hyperacusis

This paper evaluates the proportion and the audiological and other characteristics of patients with symptoms of misophonia among a population seeking help for tinnitus and/or hyperacusis at an audiology clinic (n = 257). To assess such symptoms, patients were asked "over the last 2 weeks, how often have you been bothered by any of the following problems? Feeling angry or anxious when hearing certain sounds related to eating noises, lip-smacking, sniffling, breathing, clicking sounds, tapping?". The results of routine audiological tests and self-report questionnaires were gathered retrospectively from the records of the patients. Measures included: pure tone audiometry, uncomfortable loudness levels (ULLs), and responses to the tinnitus impact questionnaire (TIQ), the hyperacusis impact questionnaire (HIQ), and the screening for anxiety and depression in tinnitus (SAD-T) questionnaire. The mean age of the patients was 53 years (SD = 16) (age range 17 to 97 years). Fifty four percent were female. Twenty-three percent of patients were classified as having misophonia. The presence and frequency of reporting misophonia symptoms were not related to audiometric thresholds, except that a steeply sloping audiogram reduced the likelihood of frequent misophonia symptoms. Those with more frequent misophonia symptoms had lower values of ULLmin (the across-frequency average of ULLs for the ear with lower average ULLs) than those with less frequent or no reported symptoms. The reported frequency of experiencing misophonia symptoms increased with increasing impact of tinnitus (TIQ score ≥9), increasing impact of hyperacusis (HIQ score >11), and symptoms of anxiety and depression (SAD-T score ≥4). It is concluded that, when assessing individuals with tinnitus and hyperacusis, it is important to screen for misophonia, particularly when ULLmin is abnormally low or the TIQ, HIQ or SAD-T score is high. This will help clinicians to distinguish patients with misophonia, guiding the choice of therapeutic strategies.

The Effectiveness of Unguided Internet-Based Cognitive Behavioral Therapy for Tinnitus for Patients with Tinnitus Alone or Combined with Hyperacusis and/or Misophonia: A Preliminary Analysis

BACKGROUND

 In the United Kingdom, audiologist-delivered cognitive behavioral therapy (CBT) is a key intervention to alleviate the distress caused by tinnitus and its comorbid hyperacusis. However, the availability of face-to-face CBT is limited, and such therapy involves significant costs. CBT provided via the internet provides a potential solution to improve access to CBT for tinnitus.

PURPOSE

 The aim was to perform a preliminary assessment of the effect of a specific program of nonguided internet-based CBT for tinnitus, denoted iCBT(T), in alleviating the problems caused by tinnitus alone or tinnitus combined with hyperacusis.

RESEARCH DESIGN

 This was a retrospective cross-sectional study.

STUDY SAMPLE

 The data for 28 people with tinnitus who completed the iCBT(T) program and answered a series of questions about their tinnitus and hearing status were included in the study. Twelve patients also reported having hyperacusis (including five also with misophonia).

DATA COLLECTION AND ANALYSIS

 The iCBT(T) program has seven self-help modules. Anonymous data were collected retrospectively from patients' answers to the questions in the iCBT(T) initial and final assessment modules. Questionnaires administered within the iCBT(T) program were: 4C Tinnitus Management Questionnaire (4C), Screening for Anxiety and Depression in Tinnitus (SAD-T), and the CBT Effectiveness Questionnaire (CBT-EQ).

RESULTS

 Responses to the 4C showed a significant improvement from pre- to posttreatment, with a medium effect size. The mean improvement was similar for those with and without hyperacusis. Responses to the SAD-T questionnaire also showed a significant improvement from pre- to posttreatment with a medium effect size. The improvement was significantly greater for participants with tinnitus alone than for participants who also had hyperacusis. For both the 4C and the SAD-T, the improvements were not significantly related to age or gender. Participants' views of the effectiveness of the iCBT(T) program were assessed using the CBT-EQ. The mean score was 50 out of a maximum of 80, indicating moderately high effectiveness. CBT-EQ scores did not differ for those with and without hyperacusis.

CONCLUSION

 Based on this preliminary analysis, the iCBT(T) program showed promising results in improving the ability to manage tinnitus and decreasing symptoms of anxiety and depression. Future studies with larger samples and control group(s) are required to further assess various aspects of this program.

Comparison of otoacoustic emissions in tinnitus and hyperacusis in adults with normal hearing sensitivity

Objective: To investigate the effect of tinnitus and/or hyperacusis on distortion product otoacoustic emission (DPOAE) measures in adults with normal hearing thresholds from 0.25 to 8 kHz, while accounting for extended high-frequency (EHF) thresholds.Design: A behavioural study consisted of comprehensive audiological assessment, validated tinnitus and hyperacusis questionnaires, DPOAE amplitudes and input/output (I/O) functions.Study sample: Data of 56 participants with normal hearing were included for the analysis. Participants were categorised into four groups: (1) without tinnitus or hyperacusis, (2) with tinnitus only, (3) with hyperacusis only, and (4) with both tinnitus and hyperacusis.Results: The groups with tinnitus showed elevated EHF thresholds compared with those without tinnitus. DPOAE amplitudes were not significantly affected by tinnitus and/or hyperacusis status; however, they were significantly affected by EHF thresholds. Further, no appreciable differences in DPOAE I/O functions were found across groups.Conclusions: The reported non-significant differences in DPOAEs in individuals with tinnitus and/or hyperacusis do not support a peripheral mechanism or an interaction between peripheral and central mechanisms underlying tinnitus or hyperacusis. Our findings, however, suggest the need to assess basal cochlear function (e.g. EHF thresholds) for a better understanding of differences in DPOAE measures in tinnitus and/or hyperacusis.

Hyperacusis: demographic, audiological, and clinical characteristics of patients at the ENT department

PURPOSE

To document whether patients with and without hyperacusis differ from each other on demographic, audiological, and clinical characteristics.

METHODS

Based on the Hyperacusis Questionnaire's (HQ) cut-off (HQ > 28), a total of 2301 participants were divided into patients with and without hyperacusis. Demographic data, scores on self-reported questionnaires [Tinnitus Functional Index (TFI), Visual Analogue Scale of tinnitus loudness (VAS_loudness), Hospital Anxiety Depression Scale (HADS)], and audiological parameters were retrospectively analysed to determine differential factors between the two groups.

RESULTS

In total, 10.9% of the patients was classified as hyperacusis patients (n = 251). They reported a significant, higher tinnitus severity (mean difference of 19 points on TFI) and mental distress (mean difference of 4 points on the HADS subscales) (p < 0.001) than patients without hyperacusis. Moreover, this group consisted of more women (45% % in hyperacusis group vs. 35% in non-hyperacusis group) and women scored significantly higher on the HQ (p < 0.001) and TFI (p < 0.01).

CONCLUSION

Patients with hyperacusis have distinctive characteristics. The presence of hyperacusis in combination with tinnitus can indicate a higher need for psychoeducation. Patients that present themselves with hyperacusis without tinnitus complaints remain a minority, yet might be underdiagnosed. Hence, future studies should disentangle tinnitus from hyperacusis. In clinical practice, greater efforts are required to increase knowledge about hyperacusis as a primary or secondary complaint and to provide individualized treatment for these patients.

Alterations in auditory brainstem response distinguish occasional and constant tinnitus

BACKGROUND

The heterogeneity of tinnitus is thought to underlie the lack of objective diagnostic measures.

METHODS

Longitudinal data from 20,349 participants of the Swedish Longitudinal Occupational Survey of Health (SLOSH) cohort from 2008 to 2018 were used to understand the dynamics of transition between occasional and constant tinnitus. The second part of the study included electrophysiological data from 405 participants of the Swedish Tinnitus Outreach Project (STOP) cohort.

RESULTS

We determined that with increasing frequency of the occasional perception of self-reported tinnitus, the odds of reporting constant tinnitus after 2 years increases from 5.62 (95% CI, 4.83–6.55) for previous tinnitus (sometimes) to 29.74 (4.82–6.55) for previous tinnitus (often). When previous tinnitus was reported to be constant, the odds of reporting it as constant after 2 years rose to 603.02 (524.74–692.98), suggesting that once transitioned to constant tinnitus, the likelihood of tinnitus to persist was much greater. Auditory brain stem responses (ABRs) from subjects reporting nontinnitus (controls), occasional tinnitus, and constant tinnitus show that wave V latency increased in constant tinnitus when compared with occasional tinnitus or nontinnitus. The ABR from occasional tinnitus was indistinguishable from that of the nontinnitus controls.

CONCLUSIONS

Our results support the hypothesis that the transition from occasional to constant tinnitus is accompanied by neuronal changes in the midbrain leading to a persisting tinnitus, which is then less likely to remit.

FUNDING

This study was supported by the GENDER-Net Co-Plus Fund (GNP-182), the European Union’s Horizon 2020 grants no. 848261 (Unification of Treatments and Interventions for Tinnitus [UNITI]) and no. 722046 (European School for Interdisciplinary Tinnitus Research [ESIT]).

Prevalence of Decreased Sound Tolerance (Hyperacusis) in Individuals With Autism Spectrum Disorder: A Meta-Analysis

OBJECTIVES

Hyperacusis, defined as decreased tolerance to sound at levels that would not trouble most individuals, is frequently observed in individuals with autism spectrum disorder (ASD). Despite the functional impairment attributable to hyperacusis, little is known about its prevalence or natural history in the ASD population. The objective of this study was to conduct a systematic review and meta-analysis estimating the current and lifetime prevalence of hyperacusis in children, adolescents, and adults with ASD. By precisely estimating the burden of hyperacusis in the ASD population, the present study aims to enhance recognition of this particular symptom of ASD and highlight the need for additional research into the causes, prevention, and treatment of hyperacusis in persons on the spectrum.

DESIGN

We searched PubMed and ProQuest to identify peer-reviewed articles published in English after January 1993. We additionally performed targeted searches of Google Scholar and the gray literature, including studies published through May 2020. Eligible studies included at least 20 individuals with diagnosed ASD of any age and reported data from which the proportion of ASD individuals with current and/or lifetime hyperacusis could be derived. To account for multiple prevalence estimates derived from the same samples, we utilized three-level Bayesian random-effects meta-analyses to estimate the current and lifetime prevalence of hyperacusis. Bayesian meta-regression was used to assess potential moderators of current hyperacusis prevalence. To reduce heterogeneity due to varying definitions of hyperacusis, we performed a sensitivity analysis on the subset of studies that ascertained hyperacusis status using the Autism Diagnostic Interview-Revised (ADI-R), a structured parent interview.

RESULTS

A total of 7783 nonduplicate articles were screened, of which 67 were included in the review and synthesis. Hyperacusis status was ascertained in multiple ways across studies, with 60 articles employing interviews or questionnaires and seven using behavioral observations or objective measures. The mean (range) age of samples in the included studies was 7.88 years (1.00 to 34.89 years). The meta-analysis of interview/questionnaire measures (k(3) = 103, nASD = 13,093) estimated the current and lifetime prevalence of hyperacusis in ASD to be 41.42% (95% CrI, 37.23 to 45.84%) and 60.58% (50.37 to 69.76%), respectively. A sensitivity analysis restricted to prevalence estimates derived from the ADI-R (k(3) = 25, nASD = 5028) produced similar values. The estimate of current hyperacusis prevalence using objective/observational measures (k(3) = 8, nASD = 488) was 27.30% (14.92 to 46.31%). Heterogeneity in the full sample of interview/questionnaire measures was substantial but not significantly explained by any tested moderator. However, prevalence increased sharply with increasing age in studies using the ADI-R (BF10 = 93.10, R2Het = 0.692).

CONCLUSIONS

In this meta-analysis, we found a high prevalence of current and lifetime hyperacusis in individuals with ASD, with a majority of individuals on the autism spectrum experiencing hyperacusis at some point in their lives. The high prevalence of hyperacusis in individuals with ASD across the lifespan highlights the need for further research on sound tolerance in this population and the development of services and/or interventions to reduce the burden of this common symptom.

Development of Tinnitus and Hyperacusis in a Mouse Model of Tobramycin Cochleotoxicity

Aminoglycosides (AG) antibiotics are a common treatment for recurrent infections in cystic fibrosis (CF) patients. AGs are highly ototoxic, resulting in a range of auditory dysfunctions. It was recently shown that the acoustic startle reflex (ASR) can assess behavioral evidence of hyperacusis and tinnitus in an amikacin cochleotoxicity mouse model. The goal of this study was to establish if tobramycin treatment led to similar changes in ASR behavior and to establish whether ebselen can prevent the development of these maladaptive neuroplastic symptoms. CBA/Ca mice were divided into three groups: Group 1 served as a control and did not receive tobramycin or ebselen, Group 2 received tobramycin (200 mg/kg/s.c.) and the vehicle (DMSO/saline/i.p.) daily for 14 continuous days, and Group 3 received the same dose/schedule of tobramycin as Group 2 and ebselen at (20 mg/kg/i.p.). Auditory brainstem response (ABR) and ASR hearing assessments were collected at baseline and 2, 6, 10, 14, and 18 weeks from the start of treatment. ASR tests included input/output (I/O) functions which assess general hearing and hyperacusis, and Gap-induced prepulse inhibition of the acoustic startle (GPIAS) to assess tinnitus. At 18 weeks, histologic analysis showed predominantly normal appearing hair cells and spiral ganglion neuron (SGN) synapses. Following 14 days of tobramycin injections, 16 kHz thresholds increased from baseline and fluctuated over the 18-week recovery period. I/O functions revealed exaggerated startle response magnitudes in 50% of mice over the same period. Gap detection deficits, representing behavioral evidence of tinnitus, were observed in a smaller subset (36%) of animals. Interestingly, increases in ABR wave III/wave I amplitude ratios were observed. These tobramycin data corroborate previous findings that AGs can result in hearing dysfunctions. We show that a 14-day course of tobramycin treatment can cause similar levels of hearing loss and tinnitus, when compared to a 14-day course of amikacin, but less hyperacusis. Evidence suggests that tinnitus and hyperacusis might be common side effects of AG antibiotics.