The role of hidden hearing loss in tinnitus: Insights from early markers of peripheral hearing damage.

Since the presence of tinnitus is not always associated with audiometric hearing loss, it has been hypothesized that hidden hearing loss may act as a potential trigger for increased central gain along the neural pathway leading to tinnitus perception. In recent years, the study of hidden hearing loss has improved with the discovery of cochlear synaptopathy and several objective diagnostic markers. This study investigated three potential markers of peripheral hidden hearing loss in subjects with tinnitus: extended high-frequency audiometric thresholds, the auditory brainstem response, and the envelope following response. In addition, speech intelligibility was measured as a functional outcome measurement of hidden hearing loss. To account for age-related hidden hearing loss, participants were grouped according to age, presence of tinnitus, and audiometric thresholds. Group comparisons were conducted to differentiate between age- and tinnitus-related effects of hidden hearing loss. All three markers revealed age-related differences, whereas no differences were observed between the tinnitus and non-tinnitus groups. However, the older tinnitus group showed improved performance on low-pass filtered speech in noise tests compared to the older non-tinnitus group. These low-pass speech in noise scores were significantly correlated with tinnitus distress, as indicated using questionnaires, and could be related to the presence of hyperacusis. Based on our observations, cochlear synaptopathy does not appear to be the underlying cause of tinnitus. The improvement in low-pass speech-in-noise could be explained by enhanced temporal fine structure encoding or hyperacusis. Therefore, we recommend that future tinnitus research takes into account age-related factors, explores low-frequency encoding, and thoroughly assesses hyperacusis.

Cortical determinants of loudness perception and auditory hypersensitivity.

Parvalbumin-expressing inhibitory neurons (PVNs) stabilize cortical network activity, generate gamma rhythms, and regulate experience-dependent plasticity. Here, we observed that activation or inactivation of PVNs functioned like a volume knob in the mouse auditory cortex (ACtx), turning neural and behavioral classification of sound level up or down over a 20dB range. PVN loudness adjustments were "sticky", such that a single bout of 40Hz PVN stimulation sustainably suppressed ACtx sound responsiveness, potentiated feedforward inhibition, and behaviorally desensitized mice to loudness. Sensory sensitivity is a cardinal feature of autism, aging, and peripheral neuropathy, prompting us to ask whether PVN stimulation can persistently desensitize mice with ACtx hyperactivity, PVN hypofunction, and loudness hypersensitivity triggered by cochlear sensorineural damage. We found that a single 16-minute bout of 40Hz PVN stimulation session restored normal loudness perception for one week, showing that perceptual deficits triggered by irreversible peripheral injuries can be reversed through targeted cortical circuit interventions.

Sound-Evoked Neural Activity in Normal-Hearing Tinnitus: Effects of Frequency and Stimulated Ear Side.

Tinnitus is a common phantom auditory percept believed to be related to plastic changes in the brain due to hearing loss. However, tinnitus can also occur in the absence of any clinical hearing loss. In this case, since there is no hearing loss, the mechanisms that drive plastic changes remain largely enigmatic. Previous studies showed subtle differences in sound-evoked brain activity associated with tinnitus in subjects with tinnitus and otherwise normal hearing, but the results are not consistent across studies. Here, we aimed to investigate these differences using monaural rather than binaural stimuli. Sound-evoked responses were measured using functional magnetic resonance imaging (MRI) in participants with and without tinnitus. All participants had clinically normal audiograms. The stimuli were pure tones with frequencies between 353 and 8000 Hz, presented monaurally. A Principal Component Analysis (PCA) of the response in the auditory cortex revealed no difference in tonotopic organization, which confirmed earlier studies. A GLM analysis showed hyperactivity in the lateral areas of the bilateral auditory cortex. Consistent with the tonotopic map, this hyperactivity mainly occurred in response to low stimulus frequencies. This may be related to hyperacusis. Furthermore, there was an interaction between stimulation side and tinnitus in the parahippocampus. This may reflect an interference between tinnitus and spatial orientation.

Bridging the Gap between Psychophysiological and Audiological Factors in the Assessment of Tinnitus: An EEG Investigation in the Beta Band.

BACKGROUND: Despite substantial progress in investigating its psychophysical complexity, tinnitus remains a scientific and clinical enigma. The present study, through an ecological and multidisciplinary approach, aims to identify associations between electroencephalographic (EEG) and psycho-audiological variables. METHODS: EEG beta activity, often related to stress and anxiety, was acquired from 12 tinnitus patients (TIN group) and 7 controls (CONT group) during an audio cognitive task and at rest. We also investigated psychological (SCL-90-R; STAI-Y; BFI-10) and audiological (THI; TQ12-I; Hyperacusis) variables using non-parametric statistics to assess differences and relationships between and within groups. RESULTS: In the TIN group, frontal beta activity positively correlated with hyperacusis, parietal activity, and trait anxiety; the latter is also associated with depression in CONT. Significant differences in paranoid ideation and openness were found between groups. CONCLUSIONS: The connection between anxiety trait, beta activity in the fronto-parietal cortices and hyperacusis provides insights into brain functioning in tinnitus patients, offering quantitative descriptions for clinicians and new multidisciplinary treatment hypotheses.

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.

Prevalence of Ear-Related Problems in Individuals Recovered From COVID-19.

Introduction: The aim was to assess prevalence of tinnitus, hyperacusis, hearing and balance problems among patients recovered from COVID-19 infection. Self-reported ear and hearing symptoms were compared in three groups comprising: confirmed COVID-19, possible COVID-19, and non-COVID-19. Materials and Methods: 1649 participants completed the survey in this cross-sectional study. The mean age was 34 years and 65% were female. Participants with confirmed and possible COVID-19 were asked if after their infection (compared to the past) they experienced hearing loss, ringing or whistling noises, fullness or blockage in their ears, loudness of the sounds that are normal to other people bother them more (an indication of hyperacusis), dizziness, giddiness, or imbalance. Results: Among participants with confirmed COVID-19, 16% reported that compared to the past their hearing has decreased, 21.5% noticed tinnitus, 22.5% aural fullness, 26.1% hyperacusis and 17.3% balance problems. Regression models showed that compared to the non-COVID-19 group, participants with confirmed COVID-19 had odds ratios (ORs) of significantly greater than 1 in predicting presence of self-reported symptoms of hearing loss, tinnitus, aural fullness, hyperacusis and balance problems, OR=1.96 (p=0.001), OR=1.63 (p=0.003), OR=1.8 (p<0.001), OR=2.2 (p<0.001), and OR=2.99 (p<0.001), respectively. Conclusions: There seem to be higher prevalence of self-report symptoms of ear-related problems among individuals with confirmed COVID-19 infection compared to a non-COVID-19 group during the pandemic.

Perceptual Consequences of Cochlear Deafferentation in Humans.

Cochlear synaptopathy, a form of cochlear deafferentation, has been demonstrated in a number of animal species, including non-human primates. Both age and noise exposure contribute to synaptopathy in animal models, indicating that it may be a common type of auditory dysfunction in humans. Temporal bone and auditory physiological data suggest that age and occupational/military noise exposure also lead to synaptopathy in humans. The predicted perceptual consequences of synaptopathy include tinnitus, hyperacusis, and difficulty with speech-in-noise perception. However, confirming the perceptual impacts of this form of cochlear deafferentation presents a particular challenge because synaptopathy can only be confirmed through post-mortem temporal bone analysis and auditory perception is difficult to evaluate in animals. Animal data suggest that deafferentation leads to increased central gain, signs of tinnitus and abnormal loudness perception, and deficits in temporal processing and signal-in-noise detection. If equivalent changes occur in humans following deafferentation, this would be expected to increase the likelihood of developing tinnitus, hyperacusis, and difficulty with speech-in-noise perception. Physiological data from humans is consistent with the hypothesis that deafferentation is associated with increased central gain and a greater likelihood of tinnitus perception, while human data on the relationship between deafferentation and hyperacusis is extremely limited. Many human studies have investigated the relationship between physiological correlates of deafferentation and difficulty with speech-in-noise perception, with mixed findings. A non-linear relationship between deafferentation and speech perception may have contributed to the mixed results. When differences in sample characteristics and study measurements are considered, the findings may be more consistent.

Noise sensitivity or hyperacusis? Comparing the Weinstein and Khalfa questionnaires in a community and a clinical samples.

Noise sensitivity and hyperacusis are decreased sound tolerance conditions that are not well delineated or defined. This paper presents the correlations and distributions of the Noise Sensitivity Scale (NSS) and the Hyperacusis Questionnaire (HQ) scores in two distinct large samples. In Study 1, a community-based sample of young healthy adults (n = 103) exhibited a strong correlation (r = 0.74) between the two questionnaires. The mean NSS and HQ scores were 54.4 ± 16.9 and 12.5 ± 7.5, respectively. NSS scores displayed a normal distribution, whereas HQ scores showed a slight positive skew. In Study 2, a clinical sample of Veterans with or without clinical comorbidities (n = 95) showed a moderate correlation (r = 0.58) between the two questionnaires. The mean scores were 66.6 ± 15.6 and 15.3 ± 7.3 on the NSS and HQ, respectively. Both questionnaires' scores followed a normal distribution. In both samples, participants who self-identified as having decreased sound tolerance scored higher on both questionnaires. These findings provide reference data from two diverse sample groups. The moderate to strong correlations observed in both studies suggest a significant overlap between noise sensitivity and hyperacusis. The results underscore that NSS and HQ should not be used interchangeably, as they aim to measure distinct constructs, however to what extent they actually do remains to be determined. Further investigation should distinguish between these conditions through a comprehensive psychometric analysis of the questionnaires and a thorough exploration of psychoacoustic, neurological, and physiological differences that set them apart.

COVID-19 Vaccination Effects on Tinnitus and Hyperacusis: Longitudinal Case study.

The case study explores COVID-19 vaccination connection to tinnitus and hyperacusis, considering its onset and exacerbation post vaccination. The subject is a 47-year-old woman with a history of bilateral tinnitus, and her hearing history was tracked from 2014 to 2023. An intense episode of tinnitus occurred in 2021, distinct from previous experiences post COVID-19 vaccination, second dose. Symptoms manifested as sudden onset of hyperacusis, pronounced "roar" type tinnitus, and a sudden decline in hearing. Audiometric results showed reduce thresholds in low frequencies and lower speech scores in the left ear. This escalation significantly affects speech understanding in group conditions and noisy environments. There was a gradual improvement in tinnitus and hyperacusis severity, but the subject has a greater problem with speech understanding. The subject's journey involved visits to specialists, multiple testing including neuroimaging, naturopath consultations, and anxiety medication. It emphasizes the importance of healthcare practitioners recognizing and documenting these issues and need for timely multidisciplinary intervention and support. Further research is necessary to better understand the relationship between COVID-19, vaccination, and auditory symptoms.

Oval and round window reinforcement surgery leads to improvements in sound tolerance and quality of life for hyperacusis patients.

PURPOSE: Hyperacusis is an audiological disorder in which patients become persistently sensitive and intolerant to everyday environmental sounds. For those patients that fail conservative options, a minimally invasive surgical procedure has been developed. MATERIALS & METHODS: Retrospective case series of 73 adult patients with hyperacusis who underwent oval and round window reinforcement surgery between 1/2017-6/2023. Small pieces of temporalis fascia were used to reinforce the round and oval windows. Patients were separated into two groups based on their preoperative speech Loudness Discomfort Level (LDL). Patients with a preoperative speech LDL ≤ 70 dB were placed in the "low LDL group" whereas patients with a preoperative speech LDL >70 dB were placed in the "high LDL group." Preoperative and one-week postoperative audiogram and speech LDLs were compared. Quality of life was assessed using the Glasgow Benefit Inventory (GBI) survey. RESULTS: 73 patients met inclusion criteria - 21 patients in the low LDL group and 52 in the high LDL group. Patients in the high LDL group significantly improved their LDLs by an average of 3.5 dB (P < 0.0001). 42 patients (80.8 %) in the high LDL group had improvement and would recommend the surgery for hyperacusis. Patients in the low LDL group significantly improved their LDL by an average of 12.9 dB (P = 0.032). Ten patients (47.6 %) from the low LDL group experienced improvement and would recommend hyperacusis surgery. CONCLUSION: Many patients with hyperacusis who undergo oval and round window reinforcement can receive significant improvement in sound tolerance and quality of life. Patients with a pre-op speech LDL > 70 dB have the greatest potential for improvement with surgery (80.8 %), probably because their hyperacusis was less severe. In the high LDL group(>70dB) the improvement in 1-10 scale went from 8.6 pre-op to 2.4 post op. In the low LDL group(<70dB) went from 9.2 pre-op to 6.8 post-op. These findings were consistent with the GBI results.

Preliminary Study on Speech in Noise Training in Children with Sensory Processing Disorder and Hyperacusis.

Hyperacusis is the perception of certain everyday sounds as too loud or painful. Past research suggests that some individuals with Sensory Processing Disorder (SPD) may also have a comorbid hyperacusis. The aim of this preliminary study was to explore if hyperacusis symptoms in children with SPD change following Speech in noise training (SPINT). This was a retrospective cross-sectional study. Data were included for 28 children with SPD and sound intolerance (12/28 were female, mean age was 8.7 ± 1.9 years old). Patients were assessed using the Persian Buffalo Model Questionnaire-Revised version (P-BMQ-R) that measures various behavioural aspects of auditory processing disorder and word in noise test (WINT) before and after SPINT. After SPINT the subscales of DEC, TFM with its Noi, and Mem, subcategories, APD, ΣCAP, and Gen of P-BMQ-R questionnaire significantly improved (P < 0.05), however, the changes in subscales of Var, INT and ORG were not statistically significant (P > 0.05). In addition, SPINT led to better performance in WINT in both ears (P < 0.05). This preliminary study showed promising result for the effect of SPINT on improving behavioural indicators of APD (as measured via P-BMQ-R and WINT) and decreasing hyperacusis symptoms (as measured via Noi).

Glycine is a transmitter in the human and chimpanzee cochlear nuclei.

Introduction: Auditory information is relayed from the cochlea via the eighth cranial nerve to the dorsal and ventral cochlear nuclei (DCN, VCN). The organization, neurochemistry and circuitry of the cochlear nuclei (CN) have been studied in many species. It is well-established that glycine is an inhibitory transmitter in the CN of rodents and cats, with glycinergic cells in the DCN and VCN. There are, however, major differences in the laminar and cellular organization of the DCN between humans (and other primates) and rodents and cats. We therefore asked whether there might also be differences in glycinergic neurotransmission in the CN. Methods: We studied brainstem sections from humans, chimpanzees, and cats. We used antibodies to glycine receptors (GLYR) to identify neurons receiving glycinergic input, and antibodies to the neuronal glycine transporter (GLYT2) to immunolabel glycinergic axons and terminals. We also examined archival sections immunostained for calretinin (CR) and nonphosphorylated neurofilament protein (NPNFP) to try to locate the octopus cell area (OCA), a region in the VCN that rodents has minimal glycinergic input. Results: In humans and chimpanzees we found widespread immunolabel for glycine receptors in DCN and in the posterior (PVCN) and anterior (AVCN) divisions of the VCN. We found a parallel distribution of GLYT2-immunolabeled fibers and puncta. The data also suggest that, as in rodents, a region containing octopus cells in cats, humans and chimpanzees has little glycinergic input. Discussion: Our results show that glycine is a major transmitter in the human and chimpanzee CN, despite the species differences in DCN organization. The sources of the glycinergic input to the CN in humans and chimpanzees are not known.

Damage-evoked signals in cochlear neurons and supporting cells.

In addition to hearing loss, damage to the cochlea can lead to gain of function pathologies such as hyperacusis. It has been proposed that painful hyperacusis, noxacusis, may be carried to the central nervous system by type II cochlear afferents, sparse, unmyelinated neurons that share morphological and neurochemical traits with nociceptive C-fibers of the somatic nervous system. Also like in skin, damage elicits spreading calcium waves within cochlear epithelia. These are mediated by extracellular ATP combined with IP3-driven release from intracellular calcium stores. Type II afferents are excited by ATP released from damaged epithelia. Thus, the genesis and propagation of epithelial calcium waves is central to cochlear pathology, and presumably hyperacusis. Damage-evoked signals in type II afferents and epithelial cells have been recorded in cochlear explants or semi-intact otic capsules. These efforts have included intracellular electrical recording, use of fluorescent calcium indicators, and visualization of an activity-dependent, intrinsic fluorescent signal. Of relevance to hyperacusis, prior noise-induced hearing loss leads to the generation of prolonged and repetitive activity in type II neurons and surrounding epithelia.

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.

Cochlear Nucleus Transcriptome of a Fragile X Mouse Model Reveals Candidate Genes for Hyperacusis.

OBJECTIVE: Fragile X Syndrome (FXS) is a hereditary form of autism spectrum disorder. It is caused by a trinucleotide repeat expansion in the Fmr1 gene, leading to a loss of Fragile X Protein (FMRP) expression. The loss of FMRP causes auditory hypersensitivity: FXS patients display hyperacusis and the Fmr1- knock-out (KO) mouse model for FXS exhibits auditory seizures. FMRP is strongly expressed in the cochlear nucleus and other auditory brainstem nuclei. We hypothesize that the Fmr1-KO mouse has altered gene expression in the cochlear nucleus that may contribute to auditory hypersensitivity. METHODS: RNA was isolated from cochlear nuclei of Fmr1-KO and WT mice. Using next-generation sequencing (RNA-seq), the transcriptomes of Fmr1-KO mice and WT mice (n = 3 each) were compared and analyzed using gene ontology programs. RESULTS: We identified 270 unique, differentially expressed genes between Fmr1-KO and WT cochlear nuclei. Upregulated genes (67%) are enriched in those encoding secreted molecules. Downregulated genes (33%) are enriched in neuronal function, including synaptic pathways, some of which are ideal candidate genes that may contribute to hyperacusis. CONCLUSION: The loss of FMRP can affect the expression of genes in the cochlear nucleus that are important for neuronal signaling. One of these, Kcnab2, which encodes a subunit of the Shaker voltage-gated potassium channel, is expressed at an abnormally low level in the Fmr1-KO cochlear nucleus. Kcnab2 and other differentially expressed genes may represent pathways for the development of hyperacusis. Future studies will be aimed at investigating the effects of these altered genes on hyperacusis. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:1363-1371, 2024.

Investigation of the relationship between hyperacusis and auditory processing difficulties in individuals with normal hearing.

PURPOSE: This study aimed to investigate the prevalence of hyperacusis and auditory processing (listening) difficulties (APDiff) in normal-hearing young adults and to explore the relationship between these two conditions. METHODS: A total of 333 participants aged 18-24 underwent pure-tone audiometry tests and completed the Khalfa Hyperacusis Questionnaire (KHQ) and the University of Cincinnati Auditory Processing Inventory (UCAPI) online. RESULTS: Hyperacusis was identified in 26.43% of participants, and APDiff in 36.04%. A strong, positive correlation was found between KHQ and UCAPI scores (r = 0.603, p < 0.001). Logistic regression models indicated that hyperacusis significantly increased the likelihood of having APDiff (OR 7.688, p < 0.001). CONCLUSION: Despite the high prevalence of hyperacusis and APDiff in young adults, few seek help from audiology clinics. Our findings highlight a significant link between hyperacusis and APDiff, emphasizing the need for screening protocols for auditory processing skills in young adults due to these conditions' potential social and academic impacts.

Occupational noise exposure, noise annoyance, hearing-related symptoms, and emotional exhaustion - a participatory-based intervention study in preschool and obstetrics care.

A participatory-based intervention was performed in Sweden, aimed at improving the sound environment in one preschool (n = 20) and one obstetric ward (n = 50), with two controls each (n = 28, n = 66). Measured sound levels, and surveys of noise annoyance, hearing-related symptoms and emotional exhaustion were collected before, and three and nine months after the interventions, comparing intervention and control groups over time. The results of this first implementation in a limited number of workplaces showed significantly worsening of hyperacusis, sound-induced auditory fatigue, emotional exhaustion and increased sound levels in the preschool, and worsening of noise annoyance in both intervention groups. Increased risk awareness, limited implementation support and lack of psychosocial interventions may explain the worsening in outcomes, as might the worse baseline in the intervention groups. The complexity of the demands in human-service workplaces calls for further intervention studies.

Exploring the origins of decreased sound tolerance in tinnitus patients.

This study aimed to confirm the characteristics of auditory function alterations in tinnitus patients with concomitant decreased sound tolerance (ST) and provide insights for developing tailored therapeutic approaches. A retrospective analysis was conducted on patient records from a tertiary university hospital's tinnitus clinic between March 2020 and June 2023. Demographic attributes and audiological profiles were reviewed. Patients were categorized into Group 1 if loudness discomfort level test outcomes were 77 dB or below, measured using an average of frequencies from 250 Hz to 8 kHz. The remaining patients were allocated to Group 2. Among the 434 tinnitus patients, 115 (26.5%) demonstrated decreased ST and were classified as Group 1. This group exhibited higher DPOAE amplitudes (p < 0.001), shortened latency, and decreased threshold of ABR wave V bilaterally (p < 0.05). No significant disparities were observed in gender, age, tinnitus handicap inventory, visual analog scale, and pure-tone audiometry results except subjective hyperacusis. Binary logistic regression analysis utilizing the forward conditional method revealed that the difference between groups was independently linked to DPOAE response at 7,277 Hz on the left side [B = 0.093, p < 0.001, EXP(B) = 1.07, 95% CI = 1.044-1.153]. Increased DPOAE amplitude and shorter and decreased ABR wave V in tinnitus patients with decreased ST might suggest a possible association with lesions in or around the superior olivary complex or higher central auditory pathway, potentially linked to the inhibition of medial olivocochlear efferents.

Prevalence and management outcomes of tonic tensor tympani syndrome in an ENT audiology tinnitus clinic in Singapore.

OBJECTIVE: Tonic tensor tympani syndrome is found in a subset of tinnitus patients who experience intra-aural and peri-aural symptoms, in addition to their tinnitus, in the absence of clinically detectable pathology. As the syndrome has not been widely reported, this study aims to determine its prevalence and evaluate the effectiveness of current management. METHODS: The tinnitus management clinic records of patients over the past six years were assessed to identify tonic tensor tympani syndrome patients and track their progress based on patient-reported Tinnitus Handicap Index scores. Patients with reversible ear pathology and temporomandibular joint disorder were excluded. RESULTS: It was found that 13 per cent of the tinnitus management patients fulfilled the criteria for tonic tensor tympani syndrome and 94 per cent of those who returned for follow up showed an improvement in their Tinnitus Handicap Index grades. CONCLUSION: This study suggests that tonic tensor tympani syndrome is a significant problem among tinnitus patients and current tinnitus management strategies contribute effectively to helping such patients habituate to their symptoms.

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.