A multidisciplinary systematic review of the treatment for chronic idiopathic tinnitus.

The majority of tinnitus patients are affected by chronic idiopathic tinnitus, and almost 60 different treatment modalities have been reported. The present study is a multidisciplinary systematic analysis of the evidence for the different forms of treatment for chronic tinnitus. The results are used to form the basis of an S3 guideline. A systematic search was carried out in PubMed and the Cochrane Library. The basis for presenting the level of evidence was the evidence classification of the Oxford Centre of Evidence-based Medicine. Whenever available, randomised controlled trials were given preference for discussing therapeutic issues. All systematic reviews and meta-analyses were assessed for their methodological quality, and effect size was taken into account. As the need for patient counselling is self-evident, specific tinnitus counselling should be performed. Due to the high level of evidence, validated tinnitus-specific, cognitive behavioural therapy is strongly recommended. In addition, auditory therapeutic measures can be recommended for the treatment of concomitant hearing loss and comorbidities; those should also be treated with drugs whenever appropriate. In particular, depression should be treated, with pharmacological support if necessary. If needed, psychiatric treatment should also be given on a case-by-case basis. With simultaneous deafness or hearing loss bordering on deafness, a CI can also be indicated. For auditory therapeutic measures, transcranial magnetic or direct current stimulation and specific forms of acoustic stimulation (noiser/masker, retraining therapy, music, and coordinated reset) for the treatment of chronic tinnitus the currently available evidence is not yet sufficient for supporting their recommendation.

Tinnitus-related distress and the personality characteristic resilience.

It has been suggested that personality traits may be prognostic for the severity of suffering from tinnitus. Resilience as measured with the Wagnild and Young resilience scale represents a positive personality characteristic that promotes adaptation to adverse life conditions including chronic health conditions. Aim of the study was to explore the relation between resilience and tinnitus severity. In a cross-sectional study with a self-report questionnaire, information on tinnitus-related distress and subjective tinnitus loudness was recorded together with the personality characteristic resilience and emotional health, a measure generated from depression, anxiety, and somatic symptom severity scales. Data from 4705 individuals with tinnitus indicate that tinnitus-related distress and to a lesser extent the experienced loudness of the tinnitus show an inverse correlation with resilience. A mediation analysis revealed that the relationship between resilience and tinnitus-related distress is mediated by emotional health. This indirect effect indicates that high resilience is associated with better emotional health or less depression, anxiety, and somatic symptom severity, which in turn is associated with a less distressing tinnitus. Validity of resilience as a predictor for tinnitus-related distress is supported but needs to be explored further in longitudinal studies including acute tinnitus patients.

Comparing the habituation of late auditory evoked potentials to loud and soft sound.

The objective fitting of hearing aids and cochlear implants remains a challenge. In particular, the determination of whether sound is perceived as too loud or comfortable represents an unsolved problem in noncooperative patients. In a first step of an ongoing study, we assess the feasibility of habituation correlates in late auditory evoked potentials (LAEPs) to discriminate between a soft sound (SS) of 50 dB SPL and a loud sound (LS) of 100 dB SPL. We applied a new sweep-to-sweep time-scale coherence measure to analyse the habituation in LAEPs, i.e., relative changes within sweep sequences. From the comparison between both stimulation levels, a total discrimination of responses to SS and LS in the individual normal hearing subject was possible. As just relative changes in SS and LS sweep sequences were considered, purely exogenously driven morphological alternations in the responses such as intensity related amplitude and latency changes were excluded from the analysis. It is concluded that the proposed method allows for the reliable detection of auditory habituation and differentiation of SS from LS. The proposed scheme might provide an electrophysiological measurement and signal processing framework for the objective detection of the most comfortable loudness level and can be used in further, more clinically oriented studies.

Objective quantification of the tinnitus decompensation by synchronization measures of auditory evoked single sweeps.

Large-scale neural correlates of the tinnitus decompensation might be used for an objective evaluation of therapies and neurofeedback based therapeutic approaches. In this study, we try to identify large-scale neural correlates of the tinnitus decompensation using wavelet phase stability criteria of single sweep sequences of late auditory evoked potentials as synchronization stability measure. The extracted measure provided an objective quantification of the tinnitus decompensation and allowed for a reliable discrimination between a group of compensated and decompensated tinnitus patients. We provide an interpretation for our results by a neural model of top-down projections based on the Jastreboff tinnitus model combined with the adaptive resonance theory which has not been applied to model tinnitus so far. Using this model, our stability measure of evoked potentials can be linked to the focus of attention on the tinnitus signal. It is concluded that the wavelet phase stability of late auditory evoked potential single sweeps might be used as objective tinnitus decompensation measure and can be interpreted in the framework of the Jastreboff tinnitus model and adaptive resonance theory.

Polydimethylsiloxane in the human vocal fold: description of partial explantation.

We describe here for the first time a partial explantation of polydimethylsiloxane in a patient 7 years after implantation caused by faulty positioning of the implant. The histopathologic examination demonstrated that the material that displayed green autofluorescence in hematoxylin-eosin staining was biologically inert and stable. Major inflammatory reaction could not be ascertained.

Alterations in Event Related Potentials (ERP) associated with tinnitus distress and attention.

Tinnitus related distress corresponds to different degrees of attention paid to the tinnitus. Shifting attention to a signal other than the tinnitus is therefore particularly difficult for patients with high tinnitus related distress. As attention effects on Event Related Potentials (ERP) have been shown this should be reflected in ERP measurements (N100, phase locking). In order to prove this hypothesis single sweep ERP recordings were obtained in 41 tinnitus patients as well as 10 control subjects during a period of time when attention was shifted to a tone (attended) and during a second phase (unattended) when they did not focus attention to the tone. Whereas tinnitus patients with low distress showed a significant reduction in both N100 amplitude and phase locking when comparing the attended and unattended measurement condition a group of patients with high tinnitus related distress did not show such ERP alterations. Using single sweep ERP measurements the results of our study show, that attention in high tinnitus related distress patients is captured by their tinnitus significantly more than in low distress patients. Furthermore our results provide the basis for future neurofeedback based tinnitus therapies aiming at maximizing the ability to shift attention away from the tinnitus.

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

BACKGROUND: 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. METHOD: 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. RESULTS: 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. CONCLUSION: 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.

Objective detection of the central auditory processing disorder: a new machine learning approach.

The objective detection of binaural interaction is of diagnostic interest for the evaluation of the central auditory processing disorder (CAPD). The beta-wave of the binaural interaction component in auditory brainstem responses has been suggested as an objective measure of binaural interaction and has been shown to be of diagnostic value in the CAPD diagnosis. However, a reliable and automated detection of the beta-wave capable of clinical use still remains a challenge. We propose a new machine learning approach to the detection of the CAPD that is based on adapted tight frame decompositions which are tailored for support vector machines with radial kernels. Using shift-invariant scale and morphological features of the binaurally evoked brainstem potentials, our approach provides at least comparable results to the beta-wave detection in view of the discrimination of subjects being at risk for CAPD and subjects being not at risk for CAPD. Furthermore, as no information from the monaurally evoked potentials is necessary, the measurement cost is reduced by two-thirds compared to the computation of the binaural interaction component. We conclude that a machine learning approach in the form of a hybrid tight frame-support vector classification is effective in the objective detection of the CAPD.

Analysis and detection of binaural interaction in auditory evoked brainstem responses by time-scale representations.

The beta-wave of the binaural interaction component (BIC) in auditory evoked brainstem responses has been shown to be an objective measure of binaural interaction. However, a reliable and automated detection of this component capable of clinical use still remains a challenge. In this study, wavelet based time-scale representations of auditory evoked brainstem responses were investigated for the analysis of binaural interaction and for an automated detection of the beta-wave. Twenty normal hearing subjects with verified normal directional hearing and speech intelligibility in noise were included in our study. In all of these subjects, the BICs exhibited a characteristic concentration of energy in the time-scale domain which allowed for an automated detection of the beta-wave. Moreover, our study provides an explanation why the beta-wave is hard to detect for larger interaural time delays using time-scale entropy based arguments. It is concluded that time-scale representations of auditory brainstem responses are well suited for the analysis of binaural interaction and allow for an automated detection of the beta-wave.

Tinnitus and insomnia: is hyperarousal the common denominator?

Tinnitus is an auditory sensation that is generated by aberrant activation within the auditory system. Sleep disturbances are a frequent problem in the tinnitus population. They are known to worsen the distress caused by the tinnitus which in turn worsens sleep quality. Beyond that, disturbed sleep is a risk factor for mental health problems and distressing tinnitus is often associated with enhanced depressivity, anxiety, and somatic symptom severity. Moreover there is evidence that therapies which alleviate tinnitus-related distress have a positive influence on sleep quality and help interrupt this vicious cycle. This suggests that distressing tinnitus and insomnia may both be promoted by similar physiological mechanisms. One candidate mechanism is hyperarousal caused by enhanced activation of the sympathetic nervous system. There is increasing evidence for hyperarousal in insomnia patients, and animal models of tinnitus and insomnia show conspicuous similarities in the activation pattern of limbic and autonomous brain regions. In this article we review the evidence for this hypothesis which may have implications for therapeutic intervention in tinnitus patients with comorbid insomnia.

Psychoacoustic tinnitus loudness and tinnitus-related distress show different associations with oscillatory brain activity.

BACKGROUND: The phantom auditory perception of subjective tinnitus is associated with aberrant brain activity as evidenced by magneto- and electroencephalographic studies. We tested the hypotheses (1) that psychoacoustically measured tinnitus loudness is related to gamma oscillatory band power, and (2) that tinnitus loudness and tinnitus-related distress are related to distinct brain activity patterns as suggested by the distinction between loudness and distress experienced by tinnitus patients. Furthermore, we explored (3) how hearing impairment, minimum masking level, and (4) psychological comorbidities are related to spontaneous oscillatory brain activity in tinnitus patients. METHODS AND FINDINGS: Resting state oscillatory brain activity recorded electroencephalographically from 46 male tinnitus patients showed a positive correlation between gamma band oscillations and psychoacoustic tinnitus loudness determined with the reconstructed tinnitus sound, but not with the other psychoacoustic loudness measures that were used. Tinnitus-related distress did also correlate with delta band activity, but at electrode positions different from those associated with tinnitus loudness. Furthermore, highly distressed tinnitus patients exhibited a higher level of theta band activity. Moreover, mean hearing loss between 0.125 kHz and 16 kHz was associated with a decrease in gamma activity, whereas minimum masking levels correlated positively with delta band power. In contrast, psychological comorbidities did not express significant correlations with oscillatory brain activity. CONCLUSION: Different clinically relevant tinnitus characteristics show distinctive associations with spontaneous brain oscillatory power. Results support hypothesis (1), but exclusively for the tinnitus loudness derived from matching to the reconstructed tinnitus sound. This suggests to preferably use the reconstructed tinnitus spectrum to determine psychoacoustic tinnitus loudness. Results also support hypothesis (2). Moreover, hearing loss and minimum masking level correlate with oscillatory power in distinctive frequency bands. The lack of an association between psychological comorbidities and oscillatory power may be attributed to the overall low level of mental health problems in the present sample.

Feasibility of an objective electrophysiological loudness scaling: a kernel-based novelty detection approach.

OBJECTIVE: The objective of our research is to structure a foundation for an electrophysiological loudness scaling measurement, in particular to estimate an uncomfortable loudness (UCL) level by using the hybrid wavelet-kernel novelty detection (HWND). METHODS AND MATERIALS: Late auditory evoked potentials (LAEPs) were obtained from 20 normal hearing adults. These LAEPs were stimulated by 4 intensity levels (60 decibel (dB) sound pressure level (SPL), 70 dB SPL, 80 dB SPL, and 90 dB SPL). We have extracted the habituation correlates in LAEPs by using HWND. For this, we employed a lattice structure-based wavelet frame decompositions for feature extraction combined with a kernel-based novelty detector. RESULTS: The group results showed that the habituation correlates degrees, i.e., relative changes within the sweep sequences, were significantly different among 60 dB SPL, 70 dB SPL, 80 dB SPL, and 90 dB SPL stimulation level, independently from the intensity related amplitude information in the averaged LAEPs. At these particular intensities, 60% of the subjects show the correlation between the novelty measures and the stimulation levels resembles a loudness scaling function, in reverse. In this paper, we have found a correlation in between the novelty measures and loudness perception as well. We have found that high ranges of loudness levels such as loud, upper level and too loud show generally 4.88% of novelty measures and comfortable ranges of loudness levels, i.e., soft, comfortable but soft, comfortable loud and comfortable but loud are generally have 12.29% of novelty measures. Additionally, we demonstrated that our sweep-to-sweep basis of post processing scheme is reliable for habituation extraction and offers an advantage of reducing experimental time as the proposed scheme need less than 20% of single sweeps in comparison to the amount that are commonly used in arithmetical average for a meaningful result. CONCLUSIONS: We assessed the feasibility of habituation correlates for an objective loudness scaling. With respect to this first feasibility study, the presented results are promising when using the described signal processing and machine learning methodology. For the group results, the novelty measures approach is able to discriminate 60 dB, 70 dB, 80 dB and 90 dB stimulated sweeps. In addition, a correlation between the novelty measures and the subjective loudness scaling is observed. However, more loudness perception and frequency specific experiments need to be conducted to determine the UCL novelty measures threshold as well as clinically oriented studies are necessary to evaluate whether this approach might be used in the objective hearing instrument fitting procedures.

Notched-noise embedded frequency specific chirps for objective audiometry using auditory brainstem responses.

It has been shown recently that chirp-evoked auditory brainstem responses (ABRs) show better performance than click stimulations, especially at low intensity levels. In this paper we present the development, test, and evaluation of a series of notched-noise embedded frequency specific chirps. ABRs were collected in healthy young control subjects using the developed stimuli. Results of the analysis of the corresponding ABRs using a time-scale phase synchronization stability (PSS) measure are also reported. The resultant wave V amplitude and latency measures showed a similar behavior as for values reported in literature. The PSS of frequency specific chirp-evoked ABRs reflected the presence of the wave V for all stimulation intensities. The scales that resulted in higher PSS are in line with previous findings, where ABRs evoked by broadband chirps were analyzed, and which stated that low frequency channels are better for the recognition and analysis of chirp-evoked ABRs. We conclude that the development and test of the series of notched-noise embedded frequency specific chirps allowed the assessment of frequency specific ABRs, showing an identifiable wave V for different intensity levels. Future work may include the development of a faster automatic recognition scheme for these frequency specific ABRs.

Tinnitus: distinguishing between subjectively perceived loudness and tinnitus-related distress.

OBJECTIVES: Overall success of current tinnitus therapies is low, which may be due to the heterogeneity of tinnitus patients. Therefore, subclassification of tinnitus patients is expected to improve therapeutic allocation, which, in turn, is hoped to improve therapeutic success for the individual patient. The present study aims to define factors that differentially influence subjectively perceived tinnitus loudness and tinnitus-related distress. METHODS: In a questionnaire-based cross-sectional survey, the data of 4705 individuals with tinnitus were analyzed. The self-report questionnaire contained items about subjective tinnitus loudness, type of onset, awareness and localization of the tinnitus, hearing impairment, chronic comorbidities, sleep quality, and psychometrically validated questionnaires addressing tinnitus-related distress, depressivity, anxiety, and somatic symptom severity. In a binary step-wise logistic regression model, we tested the predictive power of these variables on subjective tinnitus loudness and tinnitus-related distress. RESULTS: The present data contribute to the distinction between subjective tinnitus loudness and tinnitus-related distress. Whereas subjective loudness was associated with permanent awareness and binaural localization of the tinnitus, tinnitus-related distress was associated with depressivity, anxiety, and somatic symptom severity. CONCLUSIONS: Subjective tinnitus loudness and the potential presence of severe depressivity, anxiety, and somatic symptom severity should be assessed separately from tinnitus-related distress. If loud tinnitus is the major complaint together with mild or moderate tinnitus-related distress, therapies should focus on auditory perception. If levels of depressivity, anxiety or somatic symptom severity are severe, therapies and further diagnosis should focus on these symptoms at first.

A new method to analyze distortion product otoacoustic emissions (DPOAEs) in the high-frequency range up to 18 kHz using windowed periodograms.

Distortion product otoacoustic emissions (DPOAEs) are widely used as an objective examination procedure to determine cochlear function. In a clinical routine setting, the amplitude of the DPOAE signal at 2f1 .. f2 is applied as an indicator for a potential hearing loss up to 8 kHz. Due to their poor signal to noise ratio, meatal nodes from standing waves and calibration issues, high-frequency DPOAEs > 8 kHz have hardly been addressed in experimental and clinical audiology so far. Here, we present a new method of measuring DPOAE signal levels based on optimal maximum likelihood estimation with windowed power spectral density estimation of stochastic signals and filtering theory. Analysis of simulated data showed that the proposed method effectively reduces the disturbing noise floor compared to conventional averaging techniques. Robust DPOAE signals were measured in 20 ears from 10 normally hearing young adults (21 to 27 years) from 0:5 to 18 kHz. Repeated DPOAE recordings in one individual yielded a good to very good testretest reliability of the proposed method. These observations are discussed in the context of DPOAE signal processing and possible clinical applications of high-frequency DPOAE measurements.

A kernel-based novelty detection scheme for the ultra-fast detection of chirp evoked Auditory Brainstem Responses.

Auditory Brainstem Responses (ABRs) are used as objective method for diagnostics and quantification of hearing loss. Many methods for automatic recognition of ABRs have been developed, but none of them include the individual measurement setup in the analysis. The purpose of this work was to design a fast recognition scheme for chirp-evoked ABRs that is adjusted to the individual measurement condition using spontaneous electroencephalographic activity (SA). For the classification, the kernel-based novelty detection scheme used features based on the inter-sweep instantaneous phase synchronization as well as energy and entropy relations in the time-frequency domain. This method provided SA discrimination from stimulations above the hearing threshold with a minimum number of sweeps, i.e., 200 individual responses. It is concluded that the proposed paradigm, processing procedures and stimulation techniques improve the detection of ABRs in terms of the degree of objectivity, i.e., automation of procedure, and measurement time.

Phase stability analysis of chirp evoked auditory brainstem responses by Gabor frame operators.

We have recently shown that click evoked auditory brainstem responses (ABRs) can be efficiently processed using a novelty detection paradigm. Here, ABRs as a large-scale reflection of a stimulus locked neuronal group synchronization at the brainstem level are detected as novel instance-novel as compared to the spontaneous activity which does not exhibit a regular stimulus locked synchronization. In this paper we propose for the first time Gabor frame operators as an efficient feature extraction technique for ABR single sweep sequences that is in line with this paradigm. In particular, we use this decomposition technique to derive the Gabor frame phase stability (GFPS) of sweep sequences of click and chirp evoked ABRs. We show that the GFPS of chirp evoked ABRs provides a stable discrimination of the spontaneous activity from stimulations above the hearing threshold with a small number of sweeps, even at low stimulation intensities. It is concluded that the GFPS analysis represents a robust feature extraction method for ABR single sweep sequences. Further studies are necessary to evaluate the value of the presented approach for clinical applications.

A series of notched-noise embedded chirps for objective frequency specific hearing examinations.

Chirp-evoked auditory brainstem responses (ABRs) have shown a better performance compared to click-evoked ABRs, due to their temporal organization which compensates for the traveling wave delay achieving a synchronous discharge of the cochlea. In this paper we present the development and evaluation, in healthy subjects, of a series of notched noise embedded frequency specific chirps to evoke ABRs. Results of the ABRs using Phase Synchronization Stability are also reported. The assessment of frequency specific responses by using noise embedded chirps was possible, and the PSS analysis supported previous findings which stated that low frequency channels are better for the recognition and analysis of chirp-evoked ABRs. Accordingly, future analysis can be done to make a faster recognition of frequency specific chirps-evoked ABRs.

On the single sweep processing of auditory brainstem responses: click vs. chirp stimulations and active vs. passive electrodes.

We have recently shown that click evoked auditory brainstem responses (ABRs) single sweeps can efficiently be processed by a hybrid novelty detection system. This approach allowed for the objective detection of hearing thresholds in a fraction of time of conventional schemes, making it appropriate for the efficient implementation of newborn hearing screening procedures. It is the objective of this study to evaluate whether this approach might further be improved by different stimulation paradigms and electrode settings. In particular, we evaluate chirp stimulations which compensate the basilar-membrane dispersion and active electrodes which are less sensitive to movements. This is the first study which is directed to a single sweep processing of chirp evoked ABRs. By concentrating on transparent features and a minimum number of adjustable parameters, we present an objective comparison of click vs.chirp stimulations and active vs. passive electrodes in the ultrafast ABR detection. We show that chirp evoked brainstem responses and active electrodes might improve the single sweeps analysis of ABRs.Consequently, we conclude that a single sweep processing of ABRs for the objective determination of hearing thresholds can further be improved by the use of optimized chirp stimulations and active electrodes.