Loudness Measurements Research Articles

ДОСЛІДЖЕННЯ ВПЛИВУ ЧАСТОТНИХ ВЛАСТИВОСТЕЙ СЛУХУ В ПРОЦЕСІ ВИМІРЮВАННЯ ГУЧНОСТІ ЗВУЧАННЯ АУДІОКОНТЕНТУ

Nowadays the problem of correct estimation and measurement of TV- and sound broadcasting programmes loudness is of great importance. The European Broadcasting Union (EBU) has established a special investigation group, dealing with loudness estimation and normalization, similarly, ITU emphasizes on the importance of objective measurement of audio program loudness to facilitate program delivery and exchange, and to provide more comfortable listening experience for audiences. In Recommendation ITU-R BS.1770-5 the modern algorithm of objective loudness measurement is described in detail. This algorithm includes frequency weighting of the measured audio signal to assume frequency properties of human auditory system, but such weighting concerns only the lower part of sound frequency band. In this article, the authors raise the question of the necessity of taking into account the dependence of sensitivity of the human auditory system on upper frequencies of the sound band. A brief overview of the existing representations of the frequency response of hearing sensitivity when listening to different types of sound signals is provided. Also in the article are discussed the results of subjective assessment of appreciability of changes in loudness of audio content of different types (speech and music) while changing the audio signal’s level on the upper frequencies of sound band. In one case the level of audio signal was adjusted according to the equal loudness contour corresponding to 60 phones of loudness level, and in another case, according to one of the variants of the averaged psophometric curve. The results of subjective assessment for these two cases were compared with each other. For all processed sound fragments, a confidence intervals were calculated based on the indicator of appreciability of changes in loudness, percieved by the listeners, and evaluated the accuracy of the results. Based on the results obtained from subjective assessment, further ways of conducting of the research are proposed.

Therapy effect of cochleural alternating acoustic beam therapy versus traditional sound therapy for managing chronic idiopathic tinnitus patients

Idiopathic tinnitus is a common and complex disorder with no established cure. The CAABT (Cochleural Alternating Acoustic Beam Therapy CAABT), is a personalized sound therapy designed to target specific tinnitus frequencies and effectively intervene in tinnitus according to clinical tinnitus assessment. This study aimed to compare the effectiveness of the CAABT and Traditional Sound Therapy (TST) in managing chronic idiopathic tinnitus. This was a randomized, double-blind, parallel-group, single-center prospective study. Sixty adult patients with tinnitus were recruited and randomly assigned to the CAABT or TST group in a 1:1 ratio using a computer-generated randomization. The treatment lasted for 12 weeks, and participants underwent assessments using the tinnitus handicap inventory (THI), visual analog scale (VAS), tinnitus loudness measurements, and resting-state functional magnetic resonance imaging (rs-fMRI). Both groups showed significant reductions in THI scores, VAS scores, and tinnitus loudness after treatment. However, CAABT showed superiority to TST in THI Functional (p = 0.018), THI Emotional (p = 0.015), THI Catastrophic (p = 0.022), THI total score (p = 0.005) as well as VAS score (p = 0.022). More interesting, CAABT showed superiority to TST in the changes of THI scores, and VAS scores from baseline. The rs-fMRI results showed significant changes in the precuneus before and after treatment in both groups. Moreover, the CAABT group showed more changes in brain regions compared to the TST. No side effects were observed. These findings suggest that CAABT may be a promising treatment option for chronic idiopathic tinnitus, providing significant improvements in tinnitus-related symptoms and brain activity.Trial registration: ClinicalTrials.gov:NCT02774122.

Intensive Voice Treatment following Botulinum Neurotoxin Injection for a Speaker with Abductor Laryngeal Dystonia: An Exploratory Case Study.

Abductor laryngeal dystonia (ABLD) is a rare neurological voice disorder which results in sporadic opening of the vocal folds during speech. Etiology is unknown, and to date there is no identified effective behavioral treatment for it. It is hypothesized that LSVT LOUD®, which was developed to treat dysphonia secondary to Parkinson's disease, may have application to speakers with ABLD to improve outcomes beyond that with botulinum neurotoxin (BoNT) treatment alone. The participant received one injection of BoNT in each vocal fold 2 to 3 months prior to initiating intensive voice therapy via teletherapy. Objective measures of vocal loudness (dB sound pressure level), maximum phonation time, and high/low pitch frequency (Hz) were recorded in all treatment sessions and follow-up sessions. Over the course of treatment, the participant showed steady gains in phonation time, volume, pitch range, and vocal quality with a substantial reduction in aphonic voice breaks by the end of the treatment program. Perceptual symptoms of ABLD were nearly undetectable by the participant and the clinicians up to 12 months posttreatment, with no additional BoNT injections. The results suggest that LSVT LOUD® following BoNT was effective, with long-lasting improvement in vocal function, for this speaker with ABLD.

Nonnormality of sonic boom loudness metrics in the turbulent atmospheric boundary layer at large lateral distances from the flight path

Atmospheric boundary layer (ABL) turbulence causes variability of the sonic boom waveform at the ground. Recent numerical investigations of sonic boom propagation through kinematic velocity fluctuations indicate that loudness metric distributions are positively skewed relative to a normal distribution. This skewness depends on the propagation distance and turbulence intensity. Propagation simulations of N-waves and shaped booms through inhomogeneous ABL turbulence are presented. Meteorological conditions are varied to examine different daytime ABL conditions and their effect on sonic boom loudness distributions. Two outcomes are observed: (1) the loudness metric distributions become increasingly positively skewed as the propagation distance through the ABL increases, and (2) the distributions become increasingly positively skewed at the same lateral distance from the flight path as the convection level of the daytime ABL is increased. Thus, results indicate that ground level measurements of sonic boom loudness from flight tests performed at large lateral distances from the flight path may not be normally distributed, due to turbulence present in the ABL. (This research is supported by the Commercial Supersonic Technology Project of the National Aeronautics and Space Administration under Grant No. 80NSSC19K1685.)

Parkinsonics: A Randomized, Blinded, Cross-Over Trial of Group Singing for Motor and Nonmotor Symptoms in Idiopathic Parkinson Disease.

Introduction Parkinson's disease (PD) frequently causes communication difficulties due to various voice impairments and there are few treatment options for vocal/communication complaints. We assessed the effects of weekly group singing on PD patients' objective vocal and motoric function, cognition, mood, self-efficacy, and quality of life. Methods Thirty-two participants were randomly assigned to either a singing group or a facilitated discussion group weekly over 12 weeks. After 12 weeks, participants crossed over for an additional 12 weeks. Evaluations were performed at baseline and every six weeks for 30 weeks. Objective voice measures included volume/loudness (decibels), held vowel duration, jitter, shimmer, and harmonic-to-noise ratio. Additional outcome measures included patient-centered quality of life, voice-related quality of life, MDS-UPDRS, Montreal Cognitive Assessment, and questionnaires assessing depression, self-efficacy, and overall well-being. Results Twenty-six participants (16 M/10F; Hoehn & Yahr stage 2.3 (range 2–3); and age 68.6 (55–89)) completed the study. Across participants in both groups (intention-to-treat analyses), there was significant improvement from baseline in average loudness on the Cookie Theft picture description at 24 weeks (end of interventions), corresponding with improved minimal reading volumes at 24 weeks and 30 weeks (end of study). Similarly, there were improvements in minimal loudness on Rainbow passage reading at 24 and 30 weeks. There were improvements observed in the Emotional Well-Being (mean delta −12.7 points, p = 0.037) and Body Discomfort (mean delta −18.6 points, p = 0.001) domains of the PDQ-39 from baseline to week 24 in the overall cohort and greater improvement in the Communication domain for Group S than Group D after 12 weeks of singing (delta −12.9 points, p = 0.016). Baseline differences between the participant groups (age, gender, Hoehn & Yahr stage, and several voice loudness measures) and observed improvements during the weekly discussion group period limited our ability to attribute all of the above results specifically to singing (per-protocol analyses). No significant changes in other assessed outcome measures were found. Conclusions Weekly group singing may improve some aspects of conversational voice volume and quality of life in PD. Some improvements were sustained at least six weeks after interventions ended. Further investigations of the mechanism of benefit and randomized controlled studies (without crossover) to assess the longitudinal effects of singing in PD are necessary.

Broadband Amplification as Tinnitus Treatment.

This study investigated the effect of broadband amplification (125 Hz to 10 kHz) as tinnitus treatment for participants with high-frequency hearing loss and compared these effects with an active placebo condition using band-limited amplification (125 Hz to 3–4 kHz). A double-blinded crossover study. Twenty-three participants with high-frequency (≥3 kHz) hearing loss and chronic tinnitus were included in the study, and 17 completed the full treatment protocol. Two different hearing aid treatments were provided for 3 months each: Broadband amplification provided gain in the frequency range from 125 Hz to 10 kHz and band-limited amplification only provided gain in the low-frequency range (≤3–4 kHz). The effect of the two treatments on tinnitus distress was evaluated with the Tinnitus Handicap Inventory (THI) and the Tinnitus Functional Index (TFI) questionnaires. The effect of the treatment on tinnitus loudness was evaluated with a visual analog scale (VAS) for loudness and a psychoacoustic loudness measure. Furthermore, the tinnitus annoyance was evaluated with a VAS for annoyance. The tinnitus pitch was evaluated based on the tinnitus likeness spectrum. A statistically significant difference was found between the two treatment groups (broadband vs. band-limited amplification) for the treatment-related change in THI and TFI with respect to the baseline. Furthermore, a statistically significant difference was found between the two treatment conditions for the annoyance measure. Regarding the loudness measure, no statistically significant differences were found between the treatments, although there was a trend towards a lower VAS-based loudness measure resulting from the broadband amplification. No changes were observed in the tinnitus pitch between the different conditions. Overall, the results from the present study suggest that tinnitus patients with high-frequency hearing loss can experience a decrease in tinnitus-related distress and annoyance from high-frequency amplification.

Does Listening to Tinnitus Frequency-Filtered Music Relieve Tinnitus?

Background and ObjectivesTinnitus frequency-filtered music therapy aims to restore lateral inhibition to reverse tonotopic reorganization in the auditory cortex. Although the tinnitus-relieving effect of this therapy has been investigated, the results remain controversial. We performed a prospective, randomized, controlled double-blind study to determine the tinnitus-suppressing effect of tinnitus frequency-filtered music therapy.Subjects and MethodsThe study included 90 participants who were randomly categorized into an experimental group that listened to tinnitus frequency-filtered music and a control group that listened to music from which a random frequency was removed. The Tinnitus Handicap Inventory (THI) score and measures of tinnitus loudness, daily awareness, and tinnitus-induced annoyance were evaluated at the initial visit and at 3 and 6 months (final follow-up). The rates of improvement in THI scores in the two groups were also recorded.ResultsAll measured variables showed significant improvement in both groups, except the matched tinnitus loudness and minimal masking level. However, no significant intergroup differences were observed in the amount of improvement in THI scores and any other variable. The rates of improvement in THI scores were higher in the control group at 3 and 6 months.ConclusionsListening to tinnitus frequency-filtered music reduced tinnitus-induced handicaps; however, this approach was not significantly better than listening to music from which a random frequency was removed.

Sound quality metrics for improved prediction of hospital sleep disruption

Most policy, including for the healthcare environment, uses A-weighted decibels as a standard metric. A-weighting is, thus, treated as a catch-all intended to represent all or most relevant human factors. However, for protecting sleep in the healthcare environment and its attendant recuperative benefits, A-weighted metrics neglect a great deal of essential information. To illustrate this, a dataset from a prior study of sleep disruption resulting from hospital noises measured using polysomnography [Sleep disruption due to hospital noise, Buxton et al. (2012)] is reanalyzed using measures of loudness, sharpness, and tonality. Linear combinations of these variables result in improved prediction of sleep state transitions relative to the A-weighted measure initially employed. Sound quality metrics can provide additional insight into how best to ensure a sonic environment conducive to a good night’s sleep and can, thus, help decision makers build an environment that delivers restorative sleep in the service of restoration of health. [Work supported by SAND2022-0675 A.]

Human‐Caused Sound Distractors and their Impact on Operating Room Team Function

Patient safety in the Operating Room (OR) depends on unobstructed team communication. Yet the typical OR is loud, containing numerous sounds from surgical machinery overlayed with human-caused sounds. Our objective was to compare machine vs human-caused sounds for their loudness and distraction, and potential impact on team communication. After surveying OR staff about sounds that interfere with job performance and team communication, we recorded 19 machine and 48 human-caused sounds measuring their acoustical intensity. We compared peak measures of machine vs human-caused sound loudness, using Student's t-test. We observed the effect of these sounds on OR staff in 59 live surgeries, rating level of interference with team function. We visually depicted competing sounds through a spectral analysis. The survey response rate was 62.8%. 93% of respondents indicated that OR noise, especially human-caused sounds such as irrelevant conversations, interfere with team communication, hearing, and focus. OR peak decibel levels ranged from 56.8dB (surgical packaging) to 105.0dB (kicked metal stepstool). Human-caused sounds were comparable to machine-caused sounds in terms of mean peak dB levels (77.0 versus 73.8dB, p = 0.32), yet were rated as more interfering with surgical team function. The spectral analysis illustrated both machine and human-caused sound sources obscuring the surgeon's instructions. Avoidable human-caused sounds are a major source of disruption in the OR and interfere with communication and job performance. We recommend surgical team training to minimize these distractions.

Relationship between Behavioral and Objective Measures of Sound Intensity in Normal-Hearing Listeners and Hearing-Aid Users: A Pilot Study.

Background: For hearing-impaired individuals, hearing aids are clinically fit according to subjective measures of threshold and loudness. The goal of this study was to evaluate objective measures of loudness perception that might benefit hearing aid fitting. Method: Seventeen adult hearing aid users and 17 normal-hearing adults participated in the study. Outcome measures including categorical loudness scaling, cortical auditory evoked potentials (CAEPs), and pupillometry. Stimuli were 1-kHz tone bursts presented at 40, 60, and 80 dBA. Results: Categorical loudness scaling showed that loudness significantly increased with intensity for all participants (p < 0.05). For CAEPs, high intensity was associated with greater P1, N1, and P2 peak amplitude for all listeners (p < 0.05); a significant but small effect of hearing aid amplification was observed. For all participants, pupillometry showed significant effects of high intensity on pupil dilation (p < 0.05); there was no significant effect of hearing aid amplification. A Focused Principal Component analysis revealed significant correlations between subjective loudness and some of the objective measures. Conclusion: The present data suggest that intensity had a significant impact on loudness perception, CAEPs, and pupil response. The correlations suggest that pupillometry and/or CAEPs may be useful in determining comfortable amplification for hearing aids.

Lower glutamate and GABA levels in auditory cortex of tinnitus patients: a 2D-JPRESS MR spectroscopy study

We performed magnetic resonance spectroscopy (MRS) on healthy individuals with tinnitus and no hearing loss (n = 16) vs. a matched control group (n = 17) to further elucidate the role of excitatory and inhibitory neurotransmitters in tinnitus. Two-dimensional J-resolved spectroscopy (2D-JPRESS) was applied to disentangle Glutamate (Glu) from Glutamine and to estimate GABA levels in two bilateral voxels in the primary auditory cortex. Results indicated a lower Glu concentration (large effect) in right auditory cortex and lower GABA concentration (medium effect) in the left auditory cortex of the tinnitus group. Within the tinnitus group, Glu levels positively correlated with tinnitus loudness measures. While the GABA difference between groups is in line with former findings and theories about a dysfunctional auditory inhibition system in tinnitus, the novel finding of reduced Glu levels came as a surprise and is discussed in the context of a putative framework of inhibitory mechanisms related to Glu throughout the auditory pathway. Longitudinal or interventional studies could shed more light on interactions and causality of Glu and GABA in tinnitus neurochemistry.

Management of Severe Facial Nerve Cross Stimulation by Cochlear Implant Replacement to Change Pulse Shape and Grounding Configuration: A Case-series.

Objectives:To investigate the combined effect of changing pulse shape and grounding configuration to manage facial nerve stimulation (FNS) in cochlear implant (CI) recipients.Patients:Three adult CI recipients with severe FNS were offered a replacement implant when standard stimulation strategies and programming adjustments did not resolve symptoms. Our hypothesis was that the facial nerve was less likely to be activated when using anodic pulses with “mixed-mode” intra-cochlear and extra-cochlear current return.Intervention:All patients were reimplanted with an implant that uses a pseudo-monophasic anodic pulse shape, with mixed-mode grounding (stimulus mixed-mode anodic)—the Neuro Zti CI (Oticon Medical). This device also allows measurements of neural function and loudness with monopolar, symmetric biphasic pulses (stimulus MB), the clinical standard used by most CIs as a comparison.Main Outcome Measures:The combined effect of pulse shape and grounding configuration on FNS was monitored during surgery. Following CI activation, FNS symptoms and performance with the Neuro Zti implant were compared with outcomes before reimplantation.Results:FNS could only be recorded using stimulus MB for all patients. In clinical use, all patients reported reduced FNS and showed an improvement in Bamford-Kowal-Bench sentences recognition compared with immediately before reimplantation. Bamford-Kowal-Bench scores with a male speaker were lower compared with measurements taken before the onset of severe FNS for patients 1 and 2.Conclusions:In patients where CI auditory performance was severely limited by FNS, charge-balanced pseudo-monophasic stimulation mode with a mixed-mode grounding configuration limited FNS and improved loudness percept compared with standard biphasic stimulation with monopolar grounding.

Low-Boom Demonstrator Near-Field Summary for the Third AIAA Sonic Boom Prediction Workshop

A summary and statistical analysis of the near-field computational fluid dynamics (CFD) submissions for the Third AIAA Sonic Boom Prediction Workshop is provided with a focus on the C608 Low Boom Flight Test Demonstrator. The C608 is more complex in terms of geometry and propulsion boundary conditions than previous workshop cases and is more representative of vehicles with lower ground loudness and the potential for lower annoyance. The near-field signatures submitted by the participants are propagated to the ground to compute statistics of loudness measures over the vehicle sonic boom carpet. Principle component analysis is used to extract the primary variation modes. Context from previous sonic boom workshops indicates that this workshop has the lowest variation even though the case is more challenging because it is quieter and more complex. The results documented in this summary indicate that the international state-of-the-art for near-field CFD has a variation that is small enough for meaningful low-boom design and analysis. Low-boom configuration analysis methods with low variation are important tools to develop certification processes for addressing the prohibition on overland supersonic commercial flight.

Summary of Propagation Cases of the Third AIAA Sonic Boom Prediction Workshop

A summary is provided for the propagation portion of the Third AIAA Sonic Boom Prediction Workshop held on January 4–5, 2020, in conjunction with the AIAA SciTech 2020 conference. Near-field pressure waveforms for two cases were supplied at multiple azimuthal angles. Ground signatures across the breadth of the sonic boom primary carpet and their corresponding loudness metrics were requested. Each case had some required, as well as some optional, runs. The required cases included atmospheric profiles with measured data including winds. Optional cases included a level-acceleration sonic boom focusing case and prediction under standard atmospheric conditions. Participants provided ground signatures along with several loudness metrics using their best sonic boom prediction practices. All the participants’ submissions are compared and discussed for each case. Noise or loudness measures are calculated, and detailed comparisons and statistical analyses are performed and presented. Compared with previous workshops, the selected cases in the current workshop have much lower boom loudness levels. As was observed in the past workshops, the variation in the loudness measures and spread between participants’ submissions increased as the computation proceeded from undertrack locations toward the lateral cutoff. Lessons learned during this workshop are discussed, and recommendations are made for potential improvements and possible subsequent workshops as we collectively attempt to refine our analysis methods.

Assessment of Dysphonia in Children with Pompe Disease Using Auditory-Perceptual and Acoustic/Physiologic Methods.

Bulbar and respiratory weakness occur commonly in children with Pompe disease and frequently lead to dysarthria. However, changes in vocal quality associated with this motor speech disorder are poorly described. The goal of this study was to characterize the vocal function of children with Pompe disease using auditory-perceptual and physiologic/acoustic methods. High-quality voice recordings were collected from 21 children with Pompe disease. The Grade, Roughness, Breathiness, Asthenia, and Strain (GRBAS) scale was used to assess voice quality and ratings were compared to physiologic/acoustic measurements collected during sustained phonation tasks, reading of a standard passage, and repetition of a short phrase at maximal volume. Based on ratings of grade, dysphonia was present in 90% of participants and was most commonly rated as mild or moderate in severity. Duration of sustained phonation tasks was reduced and shimmer was increased in comparison to published reference values for children without dysphonia. Specific measures of loudness were found to have statistically significant relationships with perceptual ratings of grade, breathiness, asthenia, and strain. Our data suggest that dysphonia is common in children with Pompe disease and primarily reflects impairments in respiratory and laryngeal function; however, the primary cause of dysphonia remains unclear. Future studies should seek to quantify the relative contribution of deficits in individual speech subsystems on voice quality and motor speech performance more broadly.

Equivalent sound level as a predictor for road traffic noise annoyance assessment

Noise annoyance can be rated either in situ or in laboratory conditions. Regarding the , many papers indicate that only 30% of the variance in people's answers can be explained by sound level values. This value increases when a single type of noise is presented to participants in lab. However, the relationship between time structure of the noise stimulus and annoyance rating is still ambiguous. In this study road traffic noise stimuli with different time structure at three different sound levels were created. Moreover, the psychoacoustical characteristics of them were also computed. The calculated data was compared with results of the listening test in which participants rated each stimulus on the numerical ICBEN scale. Analysis showed that loudness and sound level are the dominant factors, they correlate quite well (~70%) with people's ratings. However, the different time structure of the road traffic noise at the same sound level did not evoke significantly different noise annoyance ratings. Since there are no standards available for loudness measurement, the sound level for the same type of noise remains the simplest factor to reliably predict its impact on people regarding noise annoyance.

Ten seconds of my nights: Exploring methods to measure brightness, loudness and attendance and their associations with alcohol use from video clips.

IntroductionMost evidence on associations between alcohol use behaviors and the characteristics of its social and physical context is based on self-reports from study participants and, thus, only account for their subjective impressions of the situation. This study explores the feasibility of obtaining alternative measures of loudness, brightness, and attendance (number of people) using 10-second video clips of real-life drinking occasions rated by human annotators and computer algorithms, and explores the associations of these measures with participants’ choice to drink alcohol or not.MethodsUsing a custom-built smartphone application, 215 16-25-year-olds documented characteristics of 2,380 weekend night drinking events using questionnaires and videos. Ratings of loudness, brightness, and attendance were obtained from three sources, namely in-situ participants’ ratings, video-based annotator ratings, and video-based computer algorithm ratings. Bivariate statistics explored differences in ratings across sources. Multilevel logistic regressions assessed the associations of contextual characteristics with alcohol use. Finally, model fit indices and cross-validation were used to assess the ability of each set of contextual measures to predict participants’ alcohol use.ResultsRaw ratings of brightness, loudness and attendance differed slightly across sources, but were all correlated (r = .21 to .82, all p < .001). Participants rated bars/pubs as being louder (Cohen’s d = 0.50 [95%-CI: 0.07–0.92]), and annotators rated private places as darker (d = 1.21 [95%-CI: 0.99–1.43]) when alcohol was consumed than when alcohol was not consumed. Multilevel logistic regressions showed that drinking in private places was more likely in louder (ORparticipants = 1.74 [CI: 1.31–2.32]; ORannotators = 3.22 [CI: 2.06–5.03]; ORalgorithm = 2.62 [CI: 1.83–3.76]), more attended (ORparticipants = 1.10 [CI: 1.03–1.18]; ORalgorithm = 1.19 [CI: 1.07–1.32]) and darker (OR = 0.64 [CI: 0.44–0.94]) situations. In commercial venues, drinking was more likely in darker (ORparticipants = 0.67 [CI: 0.47–0.94]; ORannotators = 0.53 [CI: 0.33–0.85]; ORalgorithm = 0.58 [CI: 0.37–0.88]) and louder (ORparticipants = 1.40 [CI: 1.02–1.92]; ORalgorithm = 2.45 [CI: 1.25–4.80]) places. Higher inference accuracies were found for the models based on the annotators’ ratings (80% to 84%) and the algorithms’ ratings (76% to 86%) than on the participants’ ratings (69% to 71%).ConclusionsSeveral contextual characteristics are associated with increased odds of drinking in private and commercial settings, and might serve as a basis for the development of prevention measures. Regarding assessment of contextual characteristics, annotators and algorithms might serve as appropriate substitutes of participants’ in-situ impressions for correlational and regression analyses despite differences in raw ratings. Collecting contextual data by means of sensors or media files is recommended for future research.

Neurophysiological correlates of residual inhibition in tinnitus: Hints for trait-like EEG power spectra

ObjectiveTo investigate oscillatory brain activity changes following acoustic stimulation in tinnitus and whether these changes are associated with behavioral measures of tinnitus loudness. Moreover, differences in ongoing brain activity between individuals with and without residual inhibition (RI) are examined (responders vs. non-responders). MethodsThree different types of noise stimuli were administered for acoustic stimulation in 45 tinnitus patients. Subjects resting state brain activity was recorded before and after stimulation via EEG alongside with subjective measurements of tinnitus loudness. ResultsDelta, theta and gamma band power increased, whereas alpha and beta power decreased from pre to post stimulation. Acoustic stimulation responders exhibited reduced gamma and a trend for enhanced alpha activity with the latter localized in the right inferior temporal gyrus. Post stimulation, individuals experiencing RI showed higher theta, alpha and beta power with a peak power difference in the alpha band localized in the right superior temporal gyrus. Neither correlations with behavioral tinnitus measures nor stimulus-specific changes in EEG activity were present. ConclusionsOur observations might be indicative of trait-specific forms of oscillatory signatures in different subsets of the tinnitus population related to acoustic tinnitus suppression. SignificanceResults and insights are not only useful to understand basic neural mechanisms behind RI but are also valuable for general neural models of tinnitus.

What Makes Tinnitus Loud?

Tinnitus loudness is a subjective measure, and it does not directly reflect either tinnitus severity or the impact on daily life. Nevertheless, loud tinnitus may be the most frequent clinical complaint of tinnitus patients. Factors contributing to the loudness of the phantom sound have rarely been studied. We evaluated both matched and self-rated loudness in a large sample of patients with tinnitus and analyzed the influencing factors among demographic, hearing, and tinnitus characteristics. Two hundred ninety-nine patients with chronic tinnitus were enrolled. We evaluated the matched loudness, minimal masking level (MML), and visual analog scale (VAS) loudness. Stepwise multiple regression analyses were performed for each loudness measure using independent variables of age, sex, time since tinnitus onset, tinnitus laterality, pure-tone average, tinnitus pitch, tinnitus handicap inventory (THI) score, VAS annoyance, disturbance and daily tinnitus duration, and depression score. We calculated bivariate correlations between each loudness measure and all independent variables. The psychoacoustic loudness measures (matched loudness and MML) were highly correlated and were affected by the hearing deficit and tinnitus pitch (Pearson r > 0.5 for pure tone averages, and r > 0.3 for tinnitus pitch for both variables, p < 0.05), whereas the subjective measurement (VAS loudness) exhibited little to no correlation with the other two measures and was related to psycho-emotional factors such as the THI score, VAS variables, and depression (Pearson r > 0.6 for VAS annoyance, r > 0.4 for VAS daily duration and disturbance and THI score, r > 0.3 for the depression score, p < 0.05). The matched tinnitus loudness and MML values were influenced principally by the extent of hearing loss and related factors, suggesting that rehabilitation using hearing aids could help reduce perception of tinnitus loudness. A psycho-emotional approach might more effectively lessen self-perceived loudness.

Subjective Loudness Using External Noise Reflects the Loudness and Distress of Tinnitus: A Cross-Sectional Study.

Subjective tinnitus loudness has been measured using loudness matches, which compare tinnitus loudness with pure tones from an audiometer. When patients compare the sound pressure of certain noises with the tinnitus loudness, however, there may be remarkable differences from the measurements according to loudness matches. Subjective loudness (SubL) is an estimation of the sound pressure of tinnitus loudness by comparison of noises considered to be most similar to tinnitus loudness of patient. We examine whether SubL is inferior to loudness matches in measurement of subjective tinnitus loudness. Single-group cross-sectional study. Included in this study were a clinical group of 111 patients with the chief complaint of subjective tinnitus. Seven of the 111 patients were excluded due to missing audiometry or questionnaire data. Patients assessed the tinnitus loudness and related distress using visual analogue scales (VAS-L and VAS-S) and answered the Tinnitus Handicap Inventory (THI). Hearing acuity, tinnitus pitch, and loudness were then measured using an audiometer. VAS-L, VAS-S, and THI scores significantly correlated with loudness match using Goodwin's method (SL2) and SubL. Subgroup analysis based on patient ages indicated that all correlations of SL2 with VAS-L, VAS-S, and THI scores were no longer seen in patients more than 60 years of age. Meanwhile, SubL correlated with VAS-L, VAS-S, and THI scores in all subgroups. SubL was a good reflection of self-reported loudness and distress of tinnitus. It may therefore be a simple and easy means of assessing tinnitus loudness and associated distress during pre-examination without an audiometer.