Effectiveness of transcutaneous vagus nerve stimulation for the treatment of tinnitus: an interventional prospective controlled study.

OBJECTIVES: The aim of this interventional non-randomised prospective controlled study was to assess the effectiveness of transcutaneous vagus nerve stimulation (tVNS) in human subjects with tinnitus. DESIGN: The ParasymTM tVNS device was paired with an auditory stimulation. Treatment and observations were conducted over 12 weeks. Audiological evaluation was performed. Responses from a set of questionnaires and quantitative electroencephalography (qEEG) before and after treatment were collected. Voice measurements were done to assess possible side-effects of tVNS. STUDY SAMPLE: The study involved 29 adults who had chronic tinnitus (15 patients who underwent tVNS paired with sounds and a control group of 14 patients who did not). RESULTS: In general, subjective and objective measurements of tinnitus showed no improvement in the study group compared to the controls, although certain parameters as gauged by the questionnaires did statistically improve. The loudness and frequency of tinnitus remained the same in both groups. For the qEEG, activity in the theta band increased significantly in the study group compared to the control group. CONCLUSIONS: The tVNS was not effective in reducing tinnitus symptoms in our study group. However, changes in the theta band suggest there might be cortical effects that might, with sustained treatment, lead to improvements.

Differential item functioning of the tinnitus handicap inventory across gender groups and subjects with or without hearing loss.

OBJECTIVES: Tinnitus is a phantom sound sensation without an external sound source. Due to its subjective and multifaceted nature it is measured using multi-item self-reported instruments. Many well-validated tinnitus-related questionnaires are available for clinical practice and scientific research, but so far no attention has been paid to their measurement invariance. The study aimed to examine measurement invariance of the Tinnitus Handicap Inventory with regard to gender and hearing impairment, and to identify the items that show differential item functioning (DIF) across the groups. DESIGN: This is a retrospective study using medical data from patients with tinnitus. They completed the Tinnitus Handicap Inventory (THI) and underwent pure-tone audiometry. STUDY SAMPLE: 1106 adult patients with tinnitus (554 women and 552 men; 320 with normal hearing and 786 with hearing loss), aged 19-84 years. RESULTS: In the analysis, multi-group confirmatory factor analysis, hybrid ordinal logistic regression, Kernel smoothing in Item Response Theory, and lasso regression were applied. Measurement invariance was demonstrated across gender, but across hearing status the measurement was non-invariant. Five items were found to have DIF. CONCLUSIONS: Researchers and clinicians should be aware of the potential risk of response bias when tinnitus severity is evaluated.

Auditory processing in normally hearing individuals with and without tinnitus: assessment with four psychoacoustic tests.

PURPOSE: In most cases, tinnitus co-exists with hearing loss, suggesting that poorer speech understanding is simply due to a lack of acoustic information reaching the central nervous system (CNS). However, it also happens that patients with tinnitus who have normal hearing also report problems with speech understanding, and it is possible to suppose that tinnitus is to blame for difficulties in perceptual processing of auditory information. The purpose of the study was to evaluate the auditory processing abilities of normally hearing subjects with and without tinnitus. METHODS: The study group comprised 97 adults, 54 of whom had normal hearing and chronic tinnitus (the study group) and 43 who had normal hearing and no tinnitus (the control group). The audiological assessment comprised pure-tone audiometry and high-frequency pure-tone audiometry, impedance audiometry, and distortion product oto-acoustic emission assessment. To evaluate possible auditory processing deficits, the Frequency Pattern Test (FPT), Duration Pattern Test (DPT), Dichotic Listening Test (DLT), and Gap Detection Threshold (GDT) tests were performed. RESULTS: The tinnitus subjects had significantly lower scores than the controls in the gap detection test (p < 0.01) and in the dichotic listening test (p < 0.001), but only for the right ear. The results for both groups were similar in the temporal ordering tests (FPT and DPT). Right-ear advantage (REA) was found for the controls, but not for the tinnitus subjects. CONCLUSION: In normally hearing patients, the presence of tinnitus may be accompanied with auditory processing difficulties.

Effectiveness of tinnitus therapy using a mobile application.

BACKGROUND: The World Health Organization reports that the number of tinnitus sufferers is increasing year on year. Given the common use of mobile devices and the availability of applications designed to support patients in tinnitus therapy and reduce tinnitus severity, patients seeking help are likely to try this form of support. The aim of this study was to evaluate the effectiveness of a mobile application in tinnitus sound therapy, in this case ReSound Tinnitus Relief™. METHODS: The study involved 52 patients hospitalized for tinnitus. All participants used the free ReSound Tinnitus Relief application for 6 months. The application is based on sound therapy. Patients were advised to use the application for at least 30 min per day, the sounds should not completely mask the tinnitus, and they should be listened to via a loudspeaker. The effects of the therapy were evaluated by means of standardized questionnaires for tinnitus severity: the Tinnitus Handicap Inventory and the Tinnitus Functional Index. RESULTS: The study showed a reduction in tinnitus severity as measured by both questionnaires. The general severity decreased after the first 3 months and again in the following 3 months of using the application. In both questionnaires the biggest changes were observed in the subscales of emotions. CONCLUSIONS: Results obtained here from standardized questionnaires indicate that the tested application may contribute to tinnitus reduction. However, it is advisable to conduct further research on the applicability of such technology in medical practice.

Self-help interventions chosen by subjects with chronic tinnitus - a retrospective study of clinical patients.

OBJECTIVE: Self-help (without specialist support) can play an important role in tinnitus therapy. The purpose of this study was to investigate what fraction of subjects with tinnitus use self-help, what techniques are most commonly used to reduce tinnitus severity, and what distinguishes patients that use self-help from others. DESIGN: retrospective, observational study. STUDY SAMPLE: Adult patients admitted to our hospital clinic (460 participants) aged 19-83 years and reporting chronic tinnitus. The survey concerned therapy attempts prior to the clinic visit as well as self-help techniques chosen freely by the patient to reduce tinnitus severity. RESULTS: Data showed that 40.9% of the respondents chose some action themselves to reduce their tinnitus severity. Among the reported self-help techniques, acoustic stimulation was the most popular. In addition, patients chose distraction attention, relaxation, meditation, yoga, and physical activity. The likelihood of undertaking self-help increases with better education and higher tinnitus severity. CONCLUSIONS: Knowledge about patients' preferences of forms of self-help may help the health practitioner suggest a more suitable form of therapy. Due to the great interest in using sound therapy in tinnitus, it would be worthwhile looking at new forms of this therapy, for example increasingly popular mobile applications.

How to Interpret Tinnitus Functional Index Scores: A Proposal for a Grading System Based on a Large Sample of Tinnitus Patients.

OBJECTIVES: The Tinnitus Functional Index (TFI) is considered the gold standard in measuring tinnitus severity. The aim of the study was to establish reference values to improve the interpretability of TFI scores. DESIGN: Results from 1114 patients with tinnitus were retrospectively analyzed. The participants were consecutive patients who attended our tertiary referral Ear, Nose, and Throat Center. The eligibility criteria were: at least 18 years old, persistent tinnitus, completed pure-tone audiometry, and answered all 25 items on the TFI. Hearing status (normal hearing vs. hearing impairment) was established according to the recommendation of the Bureau International d'Audiophonologie. Means (M) and SD on the TFI were the basis for grading tinnitus severity on four levels: low, lower moderate, upper moderate, and high. To gauge individual scores in clinical practice, percentiles are also proposed. RESULTS: All 1114 patients (586 women and 528 men) were Caucasian and aged from 19 to 87 years (M = 50.96; SD = 13.10 years). Tinnitus duration ranged from 0.5 to 50 years (M = 7.17; SD = 7.71 years). There were 258 patients with normal hearing and 856 patients with hearing loss. A score of above 65 points on TFI was established as the cutoff point for diagnosing high tinnitus severity. A regression model associating tinnitus severity with gender, age, tinnitus duration, and hearing loss was statistically significant: F(4,1109) = 8.99; p < 0.001, but the effect was very small (R2adj = 0.028) and only gender and age were associated with TFI global score, while tinnitus severity was not related to tinnitus duration or hearing loss. CONCLUSIONS: The reference values proposed here support those reported previously by Meikle et al. They are empirically based and can be used as benchmarks in clinical practice and scientific research. They make it possible to assess tinnitus severity, evaluate individual scores, and categorize individuals with tinnitus. This allows researchers to set inclusion or exclusion criteria when assigning patients to specific groups during clinical trials involving tinnitus intervention strategies.

Prevalence of tinnitus in a sample of 43,064 children in Warsaw, Poland.

OBJECTIVE: Tinnitus affects both adults and children. Children rarely complain spontaneously of tinnitus, and their parents are not aware of the condition. The prevalence of tinnitus in children differs considerably between studies, and large studies are needed to reliably estimate how many children experience tinnitus symptoms. The goal of the study was to estimate the prevalence of tinnitus in a large sample of schoolchildren. DESIGN: This study was population-based, epidemiological research, conducted in the general, paediatric population of school-age children in Warsaw, Poland. Pure-tone audiometric testing was done, and hearing thresholds were determined from 0.5 to 8 kHz. Both the children and parents answered questions about the presence of tinnitus in the child. STUDY SAMPLE: Results from 43,064 children aged 11 to 13 years old, as well as their parents, were collected. RESULTS: The study showed that tinnitus affected 3.1% of the children, but it was significantly more frequent (9%) in children with hearing loss. We found that 1.4% of the parents were aware of the presence of tinnitus in their children. CONCLUSIONS: Children should be routinely asked whether they experience tinnitus and if so, they should be included in the thorough assessment and management of the condition.

A revised grading system for the Tinnitus Handicap Inventory based on a large clinical population.

Objective: Tinnitus Handicap Inventory (THI) is one of the world's most commonly used tools to assess tinnitus severity. The aim of the current study was to establish a revised THI grading system using standard Z-scores and percentiles.Design: Cross-sectional observational study.Study sample: Adult patients (1042 participants - 518 (49.7%) female and 524 (50.3%) male) reporting tinnitus duration of a minimum of 6 months with complete documentation on patient's clinical status (age, gender, tinnitus duration and laterality, tinnitus handicap based on THI and hearing status based on pure-tone audiometry) were included in the study.Results: Multivariate analysis of variance was used to analyse the effects of gender and hearing loss on THI scores and revealed there was a significant effect of both. Consequently, separate grading systems for women and men, as well as for subjects with normal hearing and hearing loss, is proposed.Conclusions: Our findings are generally consistent with existing grading. Normative values proposed for THI scores, based on a large group of tinnitus patients, could be useful to guide decisions about appropriate intervention options or to evaluate treatment outcomes.

Clinically important change in tinnitus sensation after stapedotomy.

BACKGROUND: When measuring the treatment effect in tinnitus with multi-item outcome instruments, it is crucial for both clinical and research purposes to take into consideration clinical importance of the outcome scores. The aim of the present study is to determine minimal important change (MIC) in tinnitus which is clinically meaningful to patients with otosclerosis. METHODS: The study population was 95 patients with otosclerosis, suffering from tinnitus. They completed the Tinnitus Functional Index before stapedotomy and 3 months after the surgery. The minimal important change was estimated with the Clinical Global Impression Scale as the external criterion (anchor). The mean change method and the receiver operating characteristic (ROC) method were used to determine minimal important change in tinnitus sensation. RESULTS: The improvement in tinnitus after stapedotomy was reported by 69.4% of the patients with otosclerosis. Minimal important change in tinnitus was estimated as reduction of 8.8 points in the Tinnitus Functional Index. CONCLUSIONS: The anchor-based approach using an external criterion (anchor) allows to determine change in tinnitus sensation which is meaningful to patients after stapedotomy. The value of 8.8 points in Tinnitus Functional Index could be used as benchmark of stapedotomy effectiveness in otosclerosis patients suffering from tinnitus. Hearing difficulties comorbid with tinnitus could affect the perception of tinnitus change.

Visual Analogue Scales as a Tool for Initial Assessment of Tinnitus Severity: Psychometric Evaluation in a Clinical Population.

The aim of this study was to evaluate the psychometric properties of patient-reported visual analogue scale (VAS) ratings. All of the participants (100 Polish-speaking adults) completed a Tinnitus Functional Index (TFI) once and a 4-component VAS twice over a period of 3 days. Spearman's correlation coefficients between the VAS score and global TFI ranged from ρ = 0.52 for VAS-coping (VAS-C) to ρ = 0.81 for VAS-annoyance (VAS-A). Using the Bland-Altman method, the agreement ranged from 93% for VAS-A to 96% for VAS-distress (VAS-D). Interclass correlation coefficients ranged from 0.67 for VAS-C to 0.90 for VAS-A. The VAS cutoff points representing significant tinnitus severity ranged from 45 points for VAS-C to 66 points for VAS-D. VAS scales are a valid and reliable brief screening tool for obtaining quick information about tinnitus.

Tinnitus in patients with hearing loss due to mitochondrial DNA pathogenic variants.

PURPOSE: Tinnitus described as individual perception of phantom sound constitutes a significant medical problem and has become an essential subject of many studies conducted worldwide. In the study, we aimed to examine the prevalence of tinnitus among Polish hearing loss (HL) patients with identified mitochondrial DNA (mtDNA) variants. METHODS: Among the selected group of unrelated HL patients with known mtDNA pathogenic variants, two questionnaires were conducted, i.e. Tinnitus Handicap Inventory translated into Polish (THI-POL) and Visual Analogue Scale (VAS) for measuring subjectively perceived tinnitus loudness, distress, annoyance and possibility of coping with this condition (VASs). Pathogenic mtDNA variants were detected with real-time PCR and sequencing of the whole mtDNA. RESULTS: This is the first extensive tinnitus characterization using THI-POL and VASs questionnaires in HL patients due to mtDNA variants. We have established the prevalence of tinnitus among the studied group at 23.5%. We found that there are no statistically significant differences in the prevalence of tinnitus and its characteristic features between HL patients with known HL mtDNA variants and the general Polish population. In Polish HL patients with tinnitus, m.7511T>C was significantly more frequent than in patients without tinnitus. We observed that the prevalence of tinnitus is lower in Polish patients with m.1555A>G as compared to other available data. CONCLUSIONS: Our data suggest that the mtDNA variants causative of HL may affect tinnitus development but this effect seems to be ethnic-specific.

Tinnitus and Hearing Survey: A Polish Study of Validity and Reliability in a Clinical Population.

This study investigates the psychometric properties of the Polish version of the Tinnitus and Hearing Survey (THS-POL), which is a tool for evaluating what proportion of patients' tinnitus is due to hearing problems and what proportion is specifically due to the tinnitus. The THS-POL was created using the translation-backtranslation method. Study participants completed the THS-POL twice over a period of 3 days. The test-retest analysis shows excellent strength of correlations (THS-POL subscale A r = 0.89, subscale B r = 0.9). For subscales A and B, reliability measured using Cronbach's alpha was α = 0.86 and 0.95, respectively, in the first administration and α = 0.91 and 0.94 in the second administration. Confirmatory factor analysis confirmed a good 2-factor structure of the THS. Convergent validity evaluated using the Pearson product-moment correlation between subscale A (tinnitus) and the Tinnitus Handicap Inventory shows good correlations. In conclusion, the THS-POL is a valid and reliable screening tool to assist in deciding about the optimal management approach.

Adaptation of the Tinnitus Handicap Inventory into Polish and its testing on a clinical population of tinnitus sufferers.

OBJECTIVE: To describe how the Tinnitus Handicap Inventory (THI) was translated into Polish (THI-POL) and to present psychometric data on how well it performed in a clinical population of tinnitus sufferers. DESIGN: The original version of THI was adapted into Polish. The reliability of THI-POL was investigated using test-retest, Cronbach's alpha, endorsement rate and item-total correlation. Construct validity and convergent validity were also assessed based on confirmatory factor analysis, inter-item correlation and Pearson product-moment correlations using subscale A (Tinnitus) of the Tinnitus and Hearing Survey (THS-POL); divergent validity was checked using subscale B (Hearing) of THS-POL. STUDY SAMPLE: A group of 167 adults filled in THI-POL twice over their three-day hospitalisation period. RESULTS: Test-retest reliability for the total THI-POL scores was strong (r = 0.91). Cronbach's alpha coefficient for the total score was high (r = 0.95), confirming the questionnaire's stability. Confirmatory factor analysis (CFA) and inter-item correlation did not confirm the three-factor model. Convergent validity from the Tinnitus subscale of THS showed a positive strong (r = 0.75) correlation. Divergent validity showed only a moderate correlation. All analyses were statistically significant (p < 0.01). CONCLUSIONS: THI-POL is a valid and reliable self-administered tool, which allows the overall tinnitus handicap of Polish-speaking patients to be effectively assessed.

Persistent Olfactory and Taste Dysfunction after COVID-19.

(1) Background: One of the possible symptoms of COVID-19 is a sudden loss of smell and taste. The main aim of the study was to evaluate the severity of post-COVID-19 olfactory dysfunction (OD). A secondary aim was to assess the relationship between OD and gustatory (taste) dysfunction (GD). Margins: 2.5 cm (1 inch) at top, bottom, right, and left. (2) Methods: The study group consisted of 81 subjects (16 men and 65 women) aged between 12 and 73 years. All of the patients presented to a center for subjective OD associated with COVID-19. They were tested with a Sniffin' Sticks test (SST) for OD and a Taste Strip test (TS) for GD. (3) Anosmia was present in 18 participants (22%), hyposmia in 52 (64%), and normosmia in 11 (14%). Some 36% of the patients reported imaginary smells (phantosmia), but it did not correlate with olfactory sensitivity. Comparing the different parts of the SST showed that subjects scored lowest on the threshold part of the test. The results of the discrimination and identification parts of the test were better, implying that if the stimulus is intense enough, incorrect discrimination and identification of odors is less frequent. A sweet taste was the easiest to recognize (78% could do so), while the most difficult to recognize was salty (68%). There were weak and statistically non-significant correlations between olfactory and taste dysfunction. (4) Conclusions: The results suggest that post-COVID-19 olfactory dysfunction was more peripheral than central. Testing patients for the severity of post-COVID-19 OD may help clinicians treat the condition. Because there is no fully effective treatment, research on post-COVID-19 OD is needed.

Children's Tinnitus Questionnaire - A novel tool for assessing the impact of tinnitus on a child's everyday life.

OBJECTIVE: Self-report instruments are commonly used in tinnitus clinics, but they are presently available only for adults. There is a lack of a validated multi-item instrument to capture tinnitus-related problems in children and their impact on everyday life. This study has developed and validated a specifically child-centered questionnaire to assess the impact of tinnitus. METHODS: Development of the tool consisted of several stages. Following a pilot study on 12 children with tinnitus, a validation study was done on a further 192 children with tinnitus aged between 11 and 14 years. The children had an audiological examination, completed a Visual Analogue Scale (VAS) and the newly framed questionnaire. RESULTS: The development and validation process resulted in the new 11-item Children's Tinnitus Questionnaire (CTQ). It includes items concerning the impact of tinnitus on functional, cognitive, emotional and social domains. The validity of the new tool has been established by finding significant correlations between it and VAS loudness (r = 0.42), VAS annoyance (r = 0.67), and VAS coping (r = -0.41). Validity has also been confirmed by measuring differences in CTQ scores and 4 groups of children having graded incidences of tinnitus. The internal consistency assessed with Cronbach's alpha was high (α = 0.82). CONCLUSION: The Children's Tinnitus Questionnaire (CTQ) is the first fully validated multi-item instrument designed specifically for children. The tool has the potential to become a valuable new instrument for use in clinical practice and research; it might be useful for assessing the impact of tinnitus on those children who find that the condition creates problems in their everyday life.

ChatGPT for Tinnitus Information and Support: Response Accuracy and Retest after Three and Six Months.

Testing of ChatGPT has recently been performed over a diverse range of topics. However, most of these assessments have been based on broad domains of knowledge. Here, we test ChatGPT's knowledge of tinnitus, an important but specialized aspect of audiology and otolaryngology. Testing involved evaluating ChatGPT's answers to a defined set of 10 questions on tinnitus. Furthermore, given the technology is advancing quickly, we re-evaluated the responses to the same 10 questions 3 and 6 months later. The accuracy of the responses was rated by 6 experts (the authors) using a Likert scale ranging from 1 to 5. Most of ChatGPT's responses were rated as satisfactory or better. However, we did detect a few instances where the responses were not accurate and might be considered somewhat misleading. Over the first 3 months, the ratings generally improved, but there was no more significant improvement at 6 months. In our judgment, ChatGPT provided unexpectedly good responses, given that the questions were quite specific. Although no potentially harmful errors were identified, some mistakes could be seen as somewhat misleading. ChatGPT shows great potential if further developed by experts in specific areas, but for now, it is not yet ready for serious application.

Effect of the COVID-19 Pandemic on Resting-State Brain Activity in Individuals with Tinnitus.

This study looked at the possible effect of the COVID-19 pandemic on individuals who came to our clinic seeking relief from tinnitus. The performance of the subjects during the COVID-19 pandemic was compared with similar individuals who came to our clinic before the pandemic began. The study involved 50 adults with chronic tinnitus, made up of a study group (24 subjects tested during the COVID-19 pandemic of 2020-2021) and a control group before the pandemic began (26 subjects tested from 2013 to 2017). None of the 24 reported having contracted COVID-19. Data collection involved the Tinnitus Handicap Inventory (THI) questionnaire, audiological tests, and quantitative electroencephalography (qEEG). In terms of THI scores, there were no statistically significant differences between the two groups. However, with regard to qEEG, some changes were observed, with significant decreases in alpha and beta band activity in the study group compared to the control group, particularly over the auditory cortex. We conclude that COVID-19 did not have a discernible impact on the general well-being of individuals with tinnitus. However, it did appear to alter brain activity, specifically in the alpha and beta bands over the auditory cortex, and these reults warrant further investigation.

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.

An MR spectroscopy study of temporal areas excluding primary auditory cortex and frontal regions in subjective bilateral and unilateral tinnitus.

Previous studies indicate changes in neurotransmission along the auditory pathway in subjective tinnitus. Most authors, however, investigated brain regions including the primary auditory cortex, whose physiology can be affected by concurrent hearing deficits. In the present MR spectroscopy study we assumed increased levels of glutamate and glutamine (Glx), and other Central Nervous System metabolites in the temporal lobe outside the primary auditory cortex, in a region involved in conscious auditory perception and memory. We studied 52 participants with unilateral (n = 24) and bilateral (n = 28) tinnitus, and a control group without tinnitus (n = 25), all with no severe hearing losses and a similar hearing profile. None of the metabolite levels in the temporal regions of interest were found related to tinnitus status or laterality. Unexpectedly, we found a tendency of increased concentration of Glx in the control left medial frontal region in bilateral vs unilateral tinnitus. Slightly elevated depressive and anxiety symptoms were also shown in participants with tinnitus, as compared to healthy individuals, with the bilateral tinnitus group marginally more affected. We discuss no apparent effect in the temporal lobes, as well as the role of frontal brain areas, with respect to hearing loss, attention and psychological well-being in chronic tinnitus. We furthermore elaborate on the design-related and technical obstacles of MR spectroscopy.

The relationship between distortion product otoacoustic emissions and extended high-frequency audiometry in tinnitus patients. Part 1: normally hearing patients with unilateral tinnitus.

BACKGROUND: The aim of this study was to evaluate distortion product otoacoustic emissions (DPOAEs) and extended high-frequency (EHF) thresholds in a control group and in patients with normal hearing sensitivity in the conventional frequency range and reporting unilateral tinnitus. MATERIAL/METHODS: Seventy patients were enrolled in the study: 47 patients with tinnitus in the left ear (Group 1) and 23 patients with tinnitus in the right ear (Group 2). The control group included 60 otologically normal subjects with no history of pathological tinnitus. Pure-tone thresholds were measured at all standard frequencies from 0.25 to 8 kHz, and at 10, 12.5, 14, and 16 kHz. The DPOAEs were measured in the frequency range from approximately 0.5 to 9 kHz using the primary tones presented at 65/55 dB SPL. RESULTS: The left ears of patients in Group 1 had higher median hearing thresholds than those in the control subjects at all 4 EHFs, and lower mean DPOAE levels than those in the controls for almost all primary frequencies, but significantly lower only in the 2-kHz region. Median hearing thresholds in the right ears of patients in Group 2 were higher than those in the right ears of the control subjects in the EHF range at 12.5, 14, and 16 kHz. The mean DPOAE levels in the right ears were lower in patients from Group 2 than those in the controls for the majority of primary frequencies, but only reached statistical significance in the 8-kHz region. CONCLUSIONS: Hearing thresholds in tinnitus ears with normal hearing sensitivity in the conventional range were higher in the EHF region than those in non-tinnitus control subjects, implying that cochlear damage in the basal region may result in the perception of tinnitus. In general, DPOAE levels in tinnitus ears were lower than those in ears of non-tinnitus subjects, suggesting that subclinical cochlear impairment in limited areas, which can be revealed by DPOAEs but not by conventional audiometry, may exist in tinnitus ears. For patients with tinnitus, DPOAE measures combined with behavioral EHF hearing thresholds may provide additional clinical information about the status of the peripheral hearing.