Perceived Tinnitus Loudness Research Articles

Magnitude of extended high frequency hearing loss associated with auditory related tinnitus distress, when controlling for magnitude of hearing loss at standard frequenciesa).

Impaired thresholds at extended high frequencies (EHF) are tightly linked to the prevalence of tinnitus, but little is known about how EHF status relates to tinnitus characteristics. In the present study, 93 individuals with tinnitus underwent standard (from 0.125 to 8 kHz) and EHF (from 10 to 16 kHz) audiometry and indicated their degree of tinnitus distress by completing the tinnitus functional index and their perceived tinnitus loudness by using a numeric rating scale. Partial correlation analyses indicated that the magnitude of EHF loss was significantly associated with degree of auditory related tinnitus distress (r = 0.343, p < 0.001) when controlling for pure tone average at standard frequencies and compensating for multiple testing. It is concluded that EHF status is related specifically to auditory related tinnitus distress, but not to intrusive-, sense of control-, cognitive-, sleep-, relaxation-, quality of life-, emotional-related tinnitus distress, total tinnitus distress, or perceived tinnitus loudness.

Dual-site transcranial direct current stimulation to treat tinnitus: a randomized controlled trial.

Transcranial direct current stimulation (tDCS) has been proposed as a potential intervention for subjective tinnitus, but supporting evidence remains limited. We aimed to investigate the effect of anodal high-definition tDCS of the left temporal area and right dorsolateral prefrontal cortex on tinnitus severity. This double-blind randomized controlled trial included 77 patients (age range 18-79, 43 male) with chronic subjective tinnitus as their primary complaint. Thirty-eight subjects received six consecutive sessions of dual-site sequential high-definition-tDCS with electrodes positioned over the left temporal area and right dorsolateral prefrontal cortex. Both areas were stimulated for 15 min per session, with total stimulation time amounting to 30 min. Thirty-nine subjects received sham stimulation. The primary outcome measure was the change in tinnitus severity, as evaluated by the Tinnitus Functional Index, from baseline to a follow-up visit at 8 ± 2 weeks after treatment completion. Secondary outcomes included changes in perceived tinnitus loudness, as measured with a visual analogue scale and a tinnitus matching procedure, as well as scores on the Hospital Anxiety and Depression Scale, and the Hyperacusis Questionnaire. No differences in Tinnitus Functional Index change scores were identified between the active treatment and sham control groups (linear regression: P = 0.86). The Tinnitus Functional Index scores decreased significantly over time in both groups (P = 0.0012), indicating the presence of a considerable placebo effect. These change scores were significantly influenced by sex (linear regression: P = 0.037) and baseline symptoms of anxiety (linear regression: P = 0.049) in both groups. In general, Tinnitus Functional Index scores decreased more profoundly in males and in subjects with a higher degree of anxiety at baseline. None of the included secondary measures differed significantly between experimental arms. Our results suggest that dual-site sequential high-definition-tDCS of the left temporal area and right dorsolateral prefrontal cortex does not alleviate tinnitus severity. Interestingly, in our study population, fluctuations in tinnitus severity were influenced by gender and concurrent mental condition. It is therefore important to take these factors into account when conducting or planning randomized controlled trials in tinnitus populations.

The Effects of Tinnitus in Probabilistic Learning Tasks: Protocol for an Ecological Momentary Assessment Study.

Chronic tinnitus is an increasing worldwide health concern, causing a significant burden to the health care system each year. The COVID-19 pandemic has seen a further increase in reported cases. For people with tinnitus, symptoms are exacerbated because of social isolation and the elevated levels of anxiety and depression caused by quarantines and lockdowns. Although it has been reported that patients with tinnitus can experience changes in cognitive capabilities, changes in adaptive learning via decision-making tasks for people with tinnitus have not yet been investigated. In this study, we aim to assess state- and trait-related impairments in adaptive learning ability on probabilistic learning tasks among people with tinnitus. Given that performance in such tasks can be quantified through computational modeling methods using a small set of neural-informed model parameters, such approaches are promising in terms of the assessment of tinnitus severity. We will first examine baseline differences in the characterization of decision-making under uncertainty between healthy individuals and people with tinnitus in terms of differences in the parameters of computational models in a cross-sectional experiment. We will also investigate whether these computational markers, which capture characteristics of decision-making, can be used to understand the cognitive impact of tinnitus symptom fluctuations through a longitudinal experimental design. We have developed a mobile app, AthenaCX, to deliver e-consent and baseline tinnitus and psychological assessments as well as regular ecological momentary assessments (EMAs) of perceived tinnitus loudness and a web-based aversive version of a probabilistic decision-making task, which can be triggered based on the participants' responses to the EMA surveys. Computational models will be developed to fit participants' choice data in the task, and cognitive parameters will be estimated to characterize participants' current ability to adapt learning to the change of the simulated environment at each session when the task is triggered. Linear regression analysis will be conducted to evaluate the impacts of baseline tinnitus severity on adapting decision-making performance. Repeated measures linear regression analysis will be used to examine model-derived parameters of decision-making in measuring real-time perceived tinnitus loudness fluctuations. Ethics approval was received in December 2020 from Dublin City University (DCUREC/2021/070). The implementation of the experiments, including both the surveys and the web-based decision-making task, has been prepared. Recruitment flyers have been shared with audiologists, and a video instruction has been created to illustrate to the participants how to participate in the experiment. We expect to finish data collection over 12 months and complete data analysis 6 months after this. The results are expected to be published in December 2023. We believe that EMA with context-aware triggering can facilitate a deeper understanding of the effects of tinnitus symptom severity upon decision-making processes as measured outside of the laboratory. PRR1-10.2196/36583.

Hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness and distress in chronic tinnitus

The role of stress and its neuroendocrine mediators in tinnitus is unclear. In this study, we measure cortisol as an indicator of hypothalamus–pituitary–adrenal (HPA) axis alterations and brain-derived neurotrophic factor (BDNF) as a marker of adaptive neuroplasticity in hair of chronic tinnitus patients to investigate relationships with tinnitus-related and psychological factors. Cross-sectional data from chronic tinnitus inpatients were analyzed. Data collection included hair sampling, pure tone audiometry, tinnitus pitch and loudness matching, and psychometric questionnaires. Elastic net regressions with n-fold cross-validation were performed for cortisol (N = 91) and BDNF (N = 87). For hair-cortisol (R2 = 0.10), the strongest effects were sampling in autumn and body-mass index (BMI) (positive), followed by tinnitus loudness (positive) and smoking (negative). For hair-BDNF (R2 = 0.28), the strongest effects were hearing aid use, shift work (positive), and tinnitus loudness (negative), followed by smoking, tinnitus-related distress (Tinnitus Questionnaire), number of experienced traumatic events (negative), and physical health-related quality of life (Short Form-12 Health Survey) (positive). These findings suggest that in chronic tinnitus patients, higher perceived tinnitus loudness is associated with higher hair-cortisol and lower hair-BDNF, and higher tinnitus-related distress with lower hair-BDNF. Regarding hair-BDNF, traumatic experiences appear to have additional stress-related effects, whereas hearing aid use and high physical health-related quality of life appear beneficial. Implications include the potential use of hair-cortisol and hair-BDNF as biomarkers of tinnitus loudness or distress and the need for intensive future research into chronic stress-related HPA axis and neuroplasticity alterations in chronic tinnitus.

Sustained reduction of tinnitus several years after sequential cochlear implantation

Objective This study aimed to explore the short- and long-term effects of a second cochlear implant (CI-2) on the reduction of tinnitus annoyance and tinnitus handicap. Design In a combined retrospective and prospective cohort study, tinnitus annoyance was measured before receiving the CI-2 (Pre), more than two years after (Post1) and more than seven years after (Post2), using the Tinnitus Handicap Inventory (THI), the Visual Analog Scale for the assessment of perceived tinnitus loudness (VAS-L) and annoyance (VAS-A), and a self-report questionnaire. Study sample Twenty sequentially bilaterally implanted adults with bothersome tinnitus. Results CI-2 implantation resulted in a statistically significant reduction of tinnitus handicap from severe at Pre to mild at Post1 (THI mean score reduced from 61.3 [SD = 19.4] to 29.3 [SD = 23.5]). The reduction in tinnitus annoyance was statistically significant from Pre to Post 2 (VAS-A reduced from 7.1 [SD = 1.5] to 3.4 [SD = 2.2]). The reduction in tinnitus loudness was not statistically significant. Conclusions The provision of a CI-2 for severely and profoundly hearing-impaired individuals with bothersome tinnitus is an effective method of providing long-term tinnitus relief.

Effectiveness of Tinnitan Duo® in Subjective Tinnitus with Emotional Affectation: A Prospective, Interventional Study

To assess the effectiveness of a food supplement (Tinnitan Duo®) containing 5-hydroxytryptophan, Ginkgo biloba, magnesium, melatonin, vitamin B5 and B6, and zinc at improving tinnitus response and intensity. Prospective, single-center interventional study including patients with subjective tinnitus and emotional affectation. The primary endpoint was the change in the Tinnitus Handicap Inventory (THI) total score and the emotional subscale after 3 months of treatment. Secondary endpoints were the change from baseline to month 3 in (1) the Tinnitus Distress Rating (TDR) scale, and (2) in hearing status, and the safety profile of patients throughout the study. Sixty-one patients were included, and 29 completed the study. The THI total score was significantly reduced after 3 months of treatment in the per-protocol (PP, all the patients with no major protocol deviations) and intention-to-treat (ITT) populations (−15.7 and −7.5, respectively; p = 0.001). The emotional subscale score significantly decreased after 3 months of treatment by −5.6 in the PP (p = 0.001) and by −2.6 in the ITT populations (p = 0.001). Perceived tinnitus loudness significantly decreased after 3 months of treatment (p = 0.001). The audiogram showed no significant changes in hearing status after 3 months of treatment. Of the five adverse events (AEs) reported, all were mild or moderate, and three were related to the study treatment (two headaches and one dizziness). This new food supplement was associated with an improved tinnitus-related emotional affectation and with a good safety profile.

Tinnitus Suppression Effect of Hearing Aids in Patients With High-frequency Hearing Loss: A Randomized Double-blind Controlled Trial.

Hearing aids (HAs) with frequency lowering have been used for high-frequency hearing loss (HFHL), but their effects on tinnitus relief have not been studied extensively. This randomized double-blind trial was performed to investigate and compare tinnitus suppression effects of conventional type HAs and frequency-lowering HAs in patients with HFHL. A total of 114 patients were randomized into three groups: conventional HA using wide dynamic range compression, HA with frequency translation, and HA with linear frequency transposition. Participants wore HAs for 3 months and then discontinued their use. The final evaluation was performed at 3 months after cessation of wearing HA (6 mo after the initial visit). The Tinnitus Handicap Inventory (THI) score and additional variables, such as matched tinnitus loudness and visual analog scale scores of subjectively perceived tinnitus loudness, daily awareness, and annoyance, were measured at the initial visit and at 3- and 6-month follow-ups. THI score and most of the additional outcomes were significantly improved at 3 and 6 months (3 mo after HA removal) compared with their initial values in all three groups. The incidence rates of patients with improvements in the THI score by 20% or more were 71.0, 72.7, and 74.3% at 3 months, and 54.8, 51.6, and 59.4% at 6 months for the three groups, respectively. There were no significant differences in primary or additional variables between hearing aid types at either 3 or 6 months. This is a consolidated standards of reporting trials-guided study providing direct evidence for tinnitus suppression effects of HA alone, without accompanying counseling or any other treatments, which lasted for at least 3 months after patients stopped using HAs. HAs effectively suppressed tinnitus in patients with HFHL regardless of the amplification strategy type.

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

PurposeTinnitus 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.MethodsAmong 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.ResultsThis 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.ConclusionsOur data suggest that the mtDNA variants causative of HL may affect tinnitus development but this effect seems to be ethnic-specific.

Transition from Acute to Chronic Tinnitus: Predictors for the Development of Chronic Distressing Tinnitus.

Acute tinnitus and its transition to chronic tinnitus are poorly investigated, and factors associated with amelioration versus exacerbation are largely unknown. Aims of this study were to identify early predictors for the future development of tinnitus severity. Patients with tinnitus of no longer than 4 weeks presenting at an otolaryngologist filled out questionnaires at inclusion (T1), as well as 3 (T3), and 6 months (T4) after tinnitus onset. 6 weeks after onset, an interview was conducted over the phone (T2). An audiogram was taken at T1, perceived tinnitus loudness, and tinnitus-related distress were assessed separately and repeatedly together with oversensitivity to external sounds and the levels of depression and anxiety. Furthermore, coping strategies with illness were recorded. Complete remission until T4 was observed in 11% of the 47 participants, while voiced complaints at onset were stable in the majority. In the subgroup with a relevant level of depression at T1, tinnitus-related distress worsened in 30% until T4. For unilateral tinnitus, perceived loudness in the chronic condition correlated strongly with hearing loss at 2 kHz on the tinnitus ear, while a similar correlation was not found for tinnitus located to both ears or within the head. Results suggest early manifestation of tinnitus complaints, and stress the importance of screening all patients presenting with acute tinnitus for levels of depression and tinnitus-related distress. Furthermore, hearing levels should be monitored, and use of hearing aids should be considered to reduce tinnitus loudness after having ascertained that sound sensitivity is within normal range.

Impairments of Speech Comprehension in Patients with Tinnitus-A Review.

Tinnitus describes the subjective perception of a sound despite the absence of external stimulation. Being a sensory symptom the majority of studies focusses on the auditory pathway. In the recent years, a series of studies suggested a crucial involvement of the limbic system in the manifestation and development of chronic tinnitus. Regarding cognitive symptoms, several reviews addressed the presence of cognitive impairments in tinnitus as well and concluded that attention and memory processes are affected. Despite the importance for social communication and the reliance on a highly functional auditory system, speech comprehension remains a largely neglected field in tinnitus research. This is why we review here the existing literature on speech and language functions in tinnitus patients. Reviewed studies suggest that speech comprehension is impaired in patients with tinnitus, especially in the presence of competing noise. This is even the case in tinnitus patients with normal hearing thresholds. Additionally, speech comprehension measures seem independent of other measures such as tinnitus severity and perceived tinnitus loudness. According to the majority of authors, the speech comprehension difficulties arise as a result of central processes or dysfunctional neuroplasticity.

Preliminary analysis of the effects of tailor-made notched music therapy on chronic idiopathic tinnitus

Objective: Tailor-made notched music was applied to alleviate the symptoms of chronic idiopathic tinnitus and compared its effectiveness with other existing sound treatment of tinnitus. Methods: Subjects (n=43; ears=75 )were recruited during June 2015 to October 2016 from the out-patients of our hospital. These patients had chronic (longer than 6months) and idiopathic tinnitus, with or without significant sensorineural hearing loss. In the prospective design, the patients were randomly divided into group A (treated with tailor-made notched music) and group B (treated with analogous sound masking), and received the treatment for 3 months. The tinnitus scale, tinnitus questionnaire and audiological findings were evaluated before treatment, and at one month and three months after treatment started. Results: After onemonth of treatment, the effective rate between the two groups was 40.9% and 42.9%, there was no significant difference between the two groups (χ(2)= 0.017, P=0.897). The average VAS for patients in group A showed more decrease in group A than in group B(VAS: 1.8 vs. 0.8, the percentage : 29.5% vs. 13.6%), but there was no significant difference between the two groups (t=-1.450, P=0.155). After 3 months of treatment, the effective rates were 68.2% and 23.8%, respectively. There was significant difference between the two groups (χ(2)= 8.503, P=0.004). The difference of the VAS scores between the two groups was statistically significant (t=-3.263, P=0.002), and the VAS score of group A was less.After 3 months of treatment, there was significant decreaseinthe average tinnitus loudness for patients in group A(t=5.569, P<0.01), and there was no significant changein group B(t=-0.953, P=0.374). There was also significant decreasein the scores of tinnitus handicap inventory (THI) (F=7.334, P<0.05), loudness visual analog scale (VAS) (F=20.48, P<0.001), and the proportion of patients with moderate to severe tinnitus(χ(2)=11.289, P<0.05) in the group A, and there was no significant change in group B(F=2.198, F=0.989, χ(2)=1.651; P=0.120, P=0.378, P=0.438>0.05). Conclusions: Our resultssuggest that long-term normalized listening to tailor-made notched music, can significantly reduce the perceived tinnitus loudness in varying degrees and improve the quality of life of patients. The effects and possible mechanism of this method were discussedin this paper.

Unilateral Cochlear Implantation Reduces Tinnitus Loudness in Bimodal Hearing: A Prospective Study.

Perceptive and receptive aspects of subjective tinnitus like loudness and tinnitus-related distress are partly independent. The high percentage of hearing loss in individuals with tinnitus suggests causality of hearing impairment particularly for the tinnitus percept, leading to the hypothesis that restoration of auditory input has a larger effect on tinnitus loudness than on tinnitus-related distress. Furthermore, it is assumed that high levels of depression or anxiety prevent reductions of tinnitus loudness and distress following restoration of activity in the cochlea. This prospective study investigated the influence of unilateral cochlear implant (CI) on tinnitus in 19 postlingually deafened adults during 6 months following implantation. All had bimodal provision with the other ear being continuously supported by a hearing aid. On the day before CI implantation (T1, T2), and at about 3 and 6 months postsurgery (T3, T4), participants were questioned about their current tinnitus. Loudness was rated on a Numeric Rating Scale, distress was assessed by the TQ12 Tinnitus Questionnaire, and depression and anxiety were recorded with the Hospital Anxiety and Depression Scale. At T2, 79% experienced tinnitus, one participant developed tinnitus after implantation. Following implantation, tinnitus loudness was reduced significantly by 42%, while reductions in tinnitus-related distress (−24%), depression (−20%), and anxiety (−20%) did not attain statistical significance. Significant correlations existed between tinnitus measures, and between postimplantation tinnitus-related distress and anxiety and depression scores. Moreover, improvement of hearing in the CI ear was significantly correlated with reduction in tinnitus loudness. A new aspect of this study is the particular influence of CI provision on perceptive aspects of preexisting tinnitus (hypothesis 1), with the effect size regarding postimplant reduction of perceived tinnitus loudness (1.40) being much larger than effect sizes on the reduction of tinnitus-related distress (0.38), depression (0.53), and anxiety (0.53). Contrary to expectation both tinnitus measures reduce even in the majority of CI recipients with increased levels of anxiety or depression. This suggests that reduction of the tinnitus signal by restoring activity in the cochlea cannot be entirely compensated for by central tinnitus mechanisms and results in a reduction of perceptive and less so of reactive aspects of subjective tinnitus.

Clinical trial on tonal tinnitus with tailor-made notched music training.

BackgroundTinnitus is a result of hyper-activity/hyper-synchrony of auditory neurons coding the tinnitus frequency, which has developed due to synchronous mass activity owing to the lack of inhibition. We assume that removal of exactly these frequencies from a complex auditory stimulus will cause the brain to reorganize around tonotopic regions coding the tinnitus frequency through inhibition-induced plasticity. Based on this assumption, a novel treatment for tonal tinnitus - tailor-made notched music training (TMNMT) - has been introduced and was tested in this clinical trial.MethodsA randomized controlled trial in parallel group design was performed in a double-blinded manner. We included 100 participants with chronic, tonal tinnitus who listened to tailor-made notched music for two hours a day for three consecutive months. Our primary outcome measures were the Tinnitus Handicap Questionnaire and Visual Analog Scales measuring perceived tinnitus loudness, awareness, distress and handicap. Participants rated their tinnitus before and after the training as well as one month after cessation of the training.ResultsWhile no effect was found for the primary outcome measures, tinnitus distress, as measured by the Tinnitus Questionnaire, a secondary outcome measure, developed differently in the two groups. The treatment group showed higher distress scores while the placebo group revealed lower distress scores after the training. However, this effect did not reach significance in post-hoc analysis and disappeared at follow-up measurements. At follow-up, tinnitus loudness in the treatment group was significantly reduced as compared to the control group. Post hoc analysis, accounting for low reliability scores in the Visual Analog Scales, showed a significant reduction of the overall Visual Analog Scale mean score in the treatment group even at the post measurement.ConclusionThis is the first study on TMNMT that was planned and conducted following the CONSORT statement standards for clinical trials. The current work is one more step towards a final evaluation of TMNMT. Already after three months the effect of training with tailor-made notched music is observable in the most direct rating of tinnitus perception – the tinnitus loudness, while more global measures of tinnitus distress do not show relevant changes.Trial registrationCurrent Controlled Trials ISRCTN04840953; Trial registration date: 17.07.2013

Combination of gaps in noise detection and visual analog scale for measuring tinnitus components in patients treated with repetitive transcranial magnetic stimulation.

We aimed to evaluate gaps in noise (GIN) detection and visual analog scale (VAS) for measuring perceived tinnitus loudness and annoyance caused thereby. We quantified the outcomes and effectiveness of repetitive transcranial magnetic stimulation (rTMS) on chronic tinnitus. Fourteen tinnitus patients with normal hearing underwent a 10 day course of active 1-Hz rTMS to the left region of the temporoparietal cortex. GIN (in which the matched pitch and loudness of tinnitus was used to determine the frequency and intensity of background noise) and VAS was used to assess tinnitus loudness and the extent of annoyance caused thereby. Both ten patients with tinnitus who underwent left temporoparietal sham stimulation and fifteen volunteers with normal hearing without tinnitus participated with GIN detection as a control. Correlations between VAS scores and GIN detection were determined via Spearman's correlation analysis. The mean GIN thresholds of tinnitus-affected (5.87 ms) ears and the ears of control subjects (4.85 ms) differed significantly. In the tinnitus group, 42.8% (6/14) patients experienced significant reductions in tinnitus annoyance, as assessed by VAS. 71.4% (10/14) patients experienced significant reductions in tinnitus loudness, as evidenced by GIN evaluation. Three tinnitus subjects (21.4%) achieved 30% decrease of the threshold of GIN detection. There was no significant change in GIN detection and VAS scores after sham stimulation. A significant positive correlation was evident between GIN data and VAS scores (r=0.84, p<0.001). Gaps in noise detection, combined with VAS scores, affords a promising sensitive method by which to evaluate tinnitus loudness and annoyance. Low frequency rTMS significantly decreased tinnitus after the active, but not the sham, treatment.

Enhancing inhibition-induced plasticity in tinnitus--spectral energy contrasts in tailor-made notched music matter.

Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM). Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC) in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts.

Intracranial mapping of a cortical tinnitus system using residual inhibition

SummaryTinnitus can occur when damage to the peripheral auditory system leads to spontaneous brain activity that is interpreted as sound [1, 2]. Many abnormalities of brain activity are associated with tinnitus, but it is unclear how these relate to the phantom sound itself, as opposed to predisposing factors or secondary consequences [3]. Demonstrating “core” tinnitus correlates (processes that are both necessary and sufficient for tinnitus perception) requires high-precision recordings of neural activity combined with a behavioral paradigm in which the perception of tinnitus is manipulated and accurately reported by the subject. This has been previously impossible in animal and human research. Here we present extensive intracranial recordings from an awake, behaving tinnitus patient during short-term modifications in perceived tinnitus loudness after acoustic stimulation (residual inhibition) [4], permitting robust characterization of core tinnitus processes. As anticipated, we observed tinnitus-linked low-frequency (delta) oscillations [5–9], thought to be triggered by low-frequency bursting in the thalamus [10, 11]. Contrary to expectation, these delta changes extended far beyond circumscribed auditory cortical regions to encompass almost all of auditory cortex, plus large parts of temporal, parietal, sensorimotor, and limbic cortex. In discrete auditory, parahippocampal, and inferior parietal “hub” regions [12], these delta oscillations interacted with middle-frequency (alpha) and high-frequency (beta and gamma) activity, resulting in a coherent system of tightly coupled oscillations associated with high-level functions including memory and perception.

The neural correlates of subjectively perceived and passively matched loudness perception in auditory phantom perception.

IntroductionA fundamental question in phantom perception is determining whether the brain creates a network that represents the sound intensity of the auditory phantom as measured by tinnitus matching (in dB), or whether the phantom perception is actually only a representation of the subjectively perceived loudness.MethodsIn tinnitus patients, tinnitus loudness was tested in two ways, by a numeric rating scale for subjectively perceived loudness and a more objective tinnitus-matching test, albeit it is still a subjective measure.ResultsPassively matched tinnitus does not correlate with subjective numeric rating scale, and has no electrophysiological correlates. Subjective loudness, in a whole-brain analysis, is correlated with activity in the left anterior insula (alpha), the rostral/dorsal anterior cingulate cortex (beta), and the left parahippocampus (gamma). A ROI analysis finds correlations with the auditory cortex (high beta and gamma) as well. The theta band links gamma band activity in the auditory cortex and parahippocampus via theta–gamma nesting.ConclusionsApparently the brain generates a network that represents subjectively perceived tinnitus loudness only, which is context dependent. The subjective loudness network consists of the anterior cingulate/insula, the parahippocampus, and the auditory cortex. The gamma band activity in the parahippocampus and the auditory cortex is functionally linked via theta–gamma nested lagged phase synchronization.

Study protocol: münster tinnitus randomized controlled clinical trial-2013 based on tailor-made notched music training (TMNMT)

BackgroundTinnitus is a result of hyper-activity/hyper-synchrony of auditory neurons coding the tinnitus frequency, which has developed to synchronous mass activity owing the lack of inhibition. We assume that removal of exactly these frequency components from an auditory stimulus will cause the brain to reorganize around tonotopic regions coding the tinnitus frequency. Based on this assumption a novel treatment for tonal tinnitus - tailor-made notched music training (TMNMT) (Proc Natl Acad Sci USA 107:1207–1210, 2010; Ann N Y Acad Sci 1252:253–258, 2012; Frontiers Syst Neurosci 6:50, 2012) has been introduced and will be tested in this clinical trial on a large number of tinnitus patients.Methods and designA randomized controlled trial (RCT) in parallel group design will be performed in a double-blinded manner. The choice of the intervention we are going to apply is based on two “proof of concept” studies in humans (Proc Natl Acad Sci USA 107:1207–1210, 2010; Ann N Y Acad Sci 1252:253–258, 2012; Frontiers Syst Neurosci 6:50, 2012; PloS One 6(9):e24685, 2011) and on a recent animal study (Front Syst Neurosci 7:21, 2013).The RCT includes 100 participants with chronic, tonal tinnitus who listened to tailor-made notched music (TMNM) for two hours a day for three months. The effect of TMNMT is assessed by the tinnitus handicap questionnaire and visual analogue scales (VAS) measuring perceived tinnitus loudness, distress and handicap.DiscussionThis is the first randomized controlled trial applying TMNMT on a larger number of patients with tonal tinnitus. Our data will verify more securely and reliably the effectiveness of this kind of completely non-invasive and low-cost treatment approach on tonal tinnitus.Trial registrationCurrent Controlled Trials ISRCTN04840953

Combining Transcranial Direct Current Stimulation and Tailor-Made Notched Music Training to Decrease Tinnitus-Related Distress – A Pilot Study

The central auditory system has a crucial role in tinnitus generation and maintenance. Curative treatments for tinnitus do not yet exist. However, recent attempts in the therapeutic application of both acoustic stimulation/training procedures and electric/magnetic brain stimulation techniques have yielded promising results. Here, for the first time we combined tailor-made notched music training (TMNMT) with transcranial direct current stimulation (tDCS) in an effort to modulate TMNMT efficacy in the treatment of 32 patients with tonal tinnitus and without severe hearing loss. TMNMT is characterized by regular listening to so-called notched music, which is generated by digitally removing the frequency band of one octave width centered at the individual tinnitus frequency. TMNMT was applied for 10 subsequent days (2.5 hours of daily treatment). During the initial 5 days of treatment and the initial 30 minutes of TMNMT sessions, tDCS (current strength: 2 mA; anodal (N = 10) vs. cathodal (N = 11) vs. sham (N = 11) groups) was applied simultaneously. The active electrode was placed on the head surface over left auditory cortex; the reference electrode was put over right supra-orbital cortex. To evaluate treatment outcome, tinnitus-related distress and perceived tinnitus loudness were assessed using standardized tinnitus questionnaires and a visual analogue scale. The results showed a significant treatment effect reflected in the Tinnitus Handicap Questionnaire that was largest after 5 days of treatment. This effect remained significant at the end of follow-up 31 days after treatment cessation. Crucially, tDCS did not significantly modulate treatment efficacy - it did not make a difference whether anodal, cathodal, or sham tDCS was applied. Possible explanations for the findings and functional modifications of the experimental design for future studies (e.g. the selection of control conditions) are discussed.

Psychometric Evaluation of Visual Analog Scale for the Assessment of Chronic Tinnitus

The development of therapeutic interventions for chronic tinnitus requires sensitive and clinically responsive tools to measure treatment-induced changes in tinnitus loudness and annoyance. In this study, the authors evaluated the psychometric properties of patient-reported visual analog scales (VAS) for measuring subjectively perceived tinnitus loudness and annoyance. The authors analyzed data from a single-blind, randomized, placebo-controlled study of acoustic coordinated reset (CR) neuromodulation in patients with chronic tinnitus (trial registration: "Randomized Evaluation of Sound Evoked Treatment of Tinnitus [RESET] study"; ClinicalTrials.gov identifier: NCT00927121) to assess the reliability, validity, and minimally clinically identifiable difference (MCID) of the VAS loudness and VAS annoyance. The VAS loudness and VAS annoyance were completed at screening, at baseline, and at 5 visits during the 16 weeks of the clinical study. Data were analyzed with respect to test-retest reliability, validity, and MCID. VAS loudness and VAS annoyance showed good test-retest reliability of .8 and .79, respectively. In terms of convergent validity, VAS loudness and VAS annoyance correlated well with the tinnitus questionnaire at all clinical visits (max r = .67, p < .05). MCID estimates clustered between 10 and 15 points. VAS loudness and VAS annoyance are valid and effective measurements for capturing reductions in tinnitus severity in patients with chronic tinnitus.