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OBJECTIVE To objectively evaluate acoustic sensitivity of the implanted microphone, and maximum stable gain of a totally implantable active middle ear implant. DESIGN Prospective, single centre evaluation. STUDY SAMPLE Fourteen adult patients. RESULTS Microphone sensitivity is approx. 10 dB lower than an externally worn conventional hearing aid, at frequencies up to 4000 Hz, and substantially lower at higher frequencies. The masking level due to microphone noise, which determines the softest test tones that can be detected, is estimated at

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

Objectives Tinnitus is the perception of sound in the absence of an external physical sound source, for some people it can severely reduce the quality of life. Acoustic residual inhibition (ARI) is a suppression of tinnitus following the cessation of a sound. The present study investigated the effect of ARI on brain activity measured using EEG. Design Thirty adult participants (mean age of 58 years) experiencing chronic tinnitus (minimum 2 years) participated. Participants were presented broad band noise at 10 dB above minimum masking level (1 min followed by 4 min of silence, 4 times) counterbalanced with a control treatment of broad band noise at threshold (1 min followed by 4 min of silence, 4 times) while 64-channel EEG was simultaneously recorded. Tinnitus loudness was measured using a 9-point tinnitus loudness rating scale. Results The ARI stimulation resulted in a self-reported reduction in tinnitus loudness in 17 of the 30 participants. Tinnitus rating reduced following stimulation but gradually returned to near baseline during 4 min of silence post sound exposure; successive sound exposures resulted in lower loudness ratings. No significant reductions in loudness rating were found with the control stimulation. The EEG showed increases in power spectral density, particularly in the alpha and gamma bands, during ARI compared to the control periods. Conclusions These results contribute to the understanding of ARI and tinnitus. We recommend that there be a closer examination of the relationship between onset and offset of sound in both tinnitus and nontinnitus control participants to ascertain if EEG changes seen with ARI relate to tinnitus suppression or general postsound activity.

Introduction The auditory structures of the brainstem are involved in binaural interaction, which contributes to sound location and auditory figure-background perception. Objective To investigate the performance of young adults in the masking level difference (MLD) test, brainstem auditory-evoked potentials (BAEPs) with click stimulus, and frequency-following response (FFR), as well as to verify the correlation between the findings, considering the topographic origin of the components of these procedures. Methods A total of 20 female subjects between 18 and 30 years of age, with normal hearing and no complaints concerning central auditory processing underwent a basic audiological evaluation, as well as the MLD test, BAEP and FFR. Results The mean result on the MLD test was of 10.70 dB. There was a statistically significant difference in the absolute latencies of waves I, III and V in the BAEPs of the ears. A change in the FFR characterized by the absence of the C, E and F waves was noticed. There was a statistically significant difference in the positive correlation of wave V in the BAEPs with the MLD. There was a statistically significant difference in the positive correlation of the mean MLD and the V, A and F components of the FFR. Conclusion The mean MLD was adequate. In the BAEPs, we observed that the click stimulus transmission occurred faster in the right ear. The FFR showed absence of some components. The mean MLD correlated positively with the BAEPs and FFR.

Comodulated masking noise and binaural cues can facilitate grouping frequency components into the target sound and noise. This results in a decrease in detection thresholds, quantified as comodulation masking release (CMR) and binaural masking level difference (BMLD), respectively. However, their relevance to speech perception is unclear as most studies have used artificial stimuli different from speech. Here, we investigated the ecological validity of masking release by using stimuli with speech-like spectro-temporal dynamics. We designed stimuli reflecting formant changes in speech. Each stimulus consists of three masker bands centered at formant frequencies F1, F2, and F3 based on CV combination: /gu/, /fu/, and /pu/. Maskers were either uncorrelated or comodulated to estimate CMR. In addition, target tone was centered at F2 trajectories and presented either with no IPD or IPD of π to induce BMLD. We found that the CMR was small (< 3 dB) while BMLD was comparable to previous findings (~ 9 dB). To conclude, we suggest that features other than comodulation play a dominant role in grouping frequency components, such as the spectral proximity, the number of masker bands, and and formant trajectories.

The auditory system uses various signal properties to separate a target signal from background noise. When a target tone is preceded by a noise, the threshold for target detection can be increased or decreased depending on the type of a preceding masker. The effect of the preceding masker on the following sound can be interpreted as stream formation. The effect of stream formation is assumed to be either the result of adaptation at a low-level or high-level auditory processing. In an attempt to disentangle these, we investigated the time constant of the underlying process of adaptation by varying the length of the preceding masker. We designed stimuli consisting of the preceding masker and the following masked tone. Each stimulus induces various stream formation, affecting following target detection or masking release. Target tone was presented in comodulated masking noise and with interaural phase difference (IPD), inducing comodulation masking release (CMR) and binaural masking level difference (BMLD), respectively. We measured CMR and BMLD when the length of preceding maskers varied from 0 (no preceding masker) to 500 ms. We postulate that if the adaptation is dominated by high-level auditory processing, both CMR and BMLD will be affected by an increase in the length of the preceding masker. Results showed that CMR was more affected with longer preceding maskers from 100 ms to 500 ms compared to shorter maskers. On the contrary, the preceding masker did not affect the BMLD. Based on the results, we suggest that the adaptation to a preceding masking sound may arise from a low-level (e.g., cochlear nucleus, CN) rather than the temporal integration by the high-level auditory processing.

Aging has several effects on auditory processing with the most important effect known as speech perception impairment in noise.The aim of the present study was to investigate the effects of aging on spatial hearing using quick speech in noise (QSIN) and binaural masking level difference (BMLD) tests and speech, spatial, and qualities of hearing scale (SSQ) questionnaire.The study was carried out on 34 elderly people, aged 60-75 years, with normal peripheral hearing and 34 young participants, aged 18-25 years. Using SSQ questionnaire and QSIN and BMLD tests, the spatial auditory processing ability was compared between the two groups.Comparison of mean scores using independent t test showed that there was a significant difference in the mean scores of QSIN, BMLD tests and SSQ questionnaire between the two groups (p 0.001). Sex was not found to have any effect on the results (p 0.05).Structural and neurochemical changes that occur in different parts of the central nervous system by aging affect various aspects of spatial auditory processing, such as localization, the precedence effect, and speech perception in noise.Lower scores of older adults with normal hearing in SSQ questionnaire and behavioral tests, compared with younger participants, may be considered as their weak performance in spatial auditory processing. The results of the present study reconfirm the effects of aging on spatial auditory processing, such as localization and speech perception in noise.

The effects of aging and stimulus configuration on binaural masking level differences (BMLDs) were measured behaviorally and electrophysiologically, using the frequency-following response (FFR) to target brainstem/midbrain encoding. The tests were performed in 15 younger normal-hearing (60 yr) participants. The stimuli consisted of a 500-Hz target tone embedded in a narrowband (50-Hz bandwidth) or wideband (1,500-Hz bandwidth) noise masker. The interaural phase conditions included NoSo (tone and noise presented interaurally in-phase), NoSπ (noise presented interaurally in-phase and tone presented out-of-phase), and NπSo (noise presented interaurally out-of-phase and tone presented in-phase) configurations. In the behavioral experiment, aging reduced the magnitude of the BMLD. The magnitude of the BMLD was smaller for the NoSo–NπSo threshold difference compared with the NoSo–NoSπ threshold difference, and it was also smaller in narrowband compared with wideband conditions, consistent with previous measurements. In the electrophysiology experiment, older participants had reduced FFR magnitudes and smaller differences between configurations. There were significant changes in FFR magnitude between the NoSo to NoSπ configurations but not between the NoSo to NπSo configurations. The age-related reduction in FFR magnitudes suggests a temporal processing deficit, but no correlation was found between FFR magnitudes and behavioral BMLDs. Therefore, independent mechanisms may be contributing to the behavioral and neural deficits. Specifically, older participants had higher behavioral thresholds than younger participants for the NoSπ and NπSo configurations but had equivalent thresholds for the NoSo configuration. However, FFR magnitudes were reduced in older participants across all configurations. NEW & NOTEWORTHY Behavioral and electrophysiological testing reveal an aging effect for stimuli presented in wideband and narrowband noise conditions, such that behavioral binaural masking level differences and subcortical spectral magnitudes are reduced in older compared with younger participants. These deficits in binaural processing may limit the older participant's ability to use spatial cues to understand speech in environments containing competing sound sources.

Contains fulltext : 236627.pdf (Publisher’s version ) (Open Access) Linguistic labels exert a particularly strong top-down influence on perception. The potency of this influence has been ascribed to their ability to evoke category-diagnostic features of concepts. In doing this, they facilitate the formation of a perceptual template concordant with those features, effectively biasing perceptual activation towards the labelled category. In this study, we employ a cueing paradigm with moving, point-light stimuli across three experiments, in order to examine how the number of biological motion features (form and kinematics) encoded in lexical cues modulates the efficacy of lexical top-down influence on perception. We find that the magnitude of lexical influence on biological motion perception rises as a function of the number of biological motion-relevant features carried by both cue and target. When lexical cues encode multiple biological motion features, this influence is robust enough to mislead participants into reporting erroneous percepts, even when a masking level yielding high performance is used. 14 p.

The equalization cancellation model is often used to predict the binaural masking level difference. Previously its application to speech in noise has required separate knowledge about the speech and noise signals to maximize the signal-to-noise ratio (SNR). Here, a novel, blind equalization cancellation model is introduced that can use the mixed signals. This approach does not require any assumptions about particular sound source directions. It uses different strategies for positive and negative SNRs, with the switching between the two steered by a blind decision stage utilizing modulation cues. The output of the model is a single-channel signal with enhanced SNR, which we analyzed using the speech intelligibility index to compare speech intelligibility predictions. In a first experiment, the model was tested on experimental data obtained in a scenario with spatially separated target and masker signals. Predicted speech recognition thresholds were in good agreement with measured speech recognition thresholds with a root mean square error less than 1 dB. A second experiment investigated signals at positive SNRs, which was achieved using time compressed and low-pass filtered speech. The results demonstrated that binaural unmasking of speech occurs at positive SNRs and that the modulation-based switching strategy can predict the experimental results.

Background We investigated how the anxiety associated with COVID 19 impacts the severity of tinnitus and the outcomes of tinnitus therapy. Methods and Findings A retrospective research design was used to compare the clinical characteristics of tinnitus between patients from March to April 2020 under pandemic pressure and those from the matching period in 2019. Tinnitus severity was evaluated using the Tinnitus Handicap Inventory (THI) questionnaire and the minimum masking level (MML) measure while anxiety was quantified using the Zung Self-rating Anxiety Scale (SAS). The assessments were repeated after a 2-month interval, in which sound therapy was applied to a subgroup of patients. In all, 94 and 70 cases were reported in the 2020 and 2019 groups, respectively. The effects of the pandemic on emotional status were evident from a higher incidence of anxiety and much higher SAS scores in the 2020 group. There was also an increase in the THI scores in the 2020 group, but the between-year difference was smaller than that of the SAS score. Moreover, there was no between-year difference in MML or the treatment effect, as measured via both THI and MML. Furthermore, the reduction in SAS score in the second assessment was significantly smaller in the 2020 group. However, a positive correlation between the initial SAS score and the improvement was seen within the 2020 group. Conclusions Anxiety increased greatly in tinnitus subjects due to the COVID 19 pandemic. However, this was not associated with an increase in tinnitus severity in 2020. Instead, there was no between-year difference in the THI score or MML or in the improvement of either measure after treatment. The smaller improvement in SAS score and the positive correlation with the initial SAS score in the 2020 group suggests that the SAS score change in this group might largely be due to the natural relief of pressure as the pandemic decelerated in China. Therefore, the anxiety change induced by the COVID 19 pandemic is not likely to have a strong impact on tinnitus.

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance.Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer.Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD.Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.

Background: The typical masking level differences (MLD) paradigm involves homophasic and antiphasic masking conditions. Objectives of the study were to develop homophasic and antiphasic stimulus, to find out the effect of signal frequency, of age on MLD when all the antiphasic conditions are compared to the homophasic S0N0 and SπNπ condition and to find out effect of interaural time delay of stimulus on aging.Methods: 90 participants were divided into 3 groups of young adults, early presbycusic adults and geriatric presbycusic adults. Various stimuli were developed and presented. The MLD were using homophasic and antiphasic stimuli at 4 frequencies 250, 500, 1000 and 2000 Hz. Subsequently these were statistically analyzed using ANOVA and paired t test.Results: All the conditions used in the study had some condition with and without significant differences. However, at 500 Hz in S0N0 homophasic condition all four antiphasic conditions among groups and MLD and Interaural time delay between groups showed significant differences were present.Conclusions: From these findings, the best frequency is 500 Hz as the homophasic S0N0 baseline condition. A significant difference between the groups indicated presence of age-related effect on MLD and interaural time delay, suggesting that age related changes can be observed in the binaural hearing and temporal processing of the signals and can be measured using MLD.

Masking has been used to study human perception of tactile stimuli, including those created on haptic touch screens. Earlier studies have investigated the effect of in-site masking on tactile perception of electrovibration. In this study, we investigated whether it is possible to change the detection threshold of electrovibration at fingertip of index finger via remote masking, i.e. by applying a (mechanical) vibrotactile stimulus on the proximal phalanx of the same finger. The masking stimuli were generated by a voice coil (Haptuator). For eight participants, we first measured the detection thresholds for electrovibration at the fingertip and for vibrotactile stimuli at the proximal phalanx. Then, the vibrations on the skin were measured at four different locations on the index finger of subjects to investigate how the mechanical masking stimulus propagated as the masking level was varied. Finally, electrovibration thresholds were measured in the presence of vibrotactile masking stimuli. Our results show that vibrotactile masking stimuli generated sub-threshold vibrations around fingertip and, hence, probably did not mechanically interfere with the electrovibration stimulus. However, there was a clear psychophysical masking effect due to central neural processes. Electrovibration absolute threshold increased approximately 0.19 dB for each dB increase in the masking level., Scientific and Technological Research Council of Turkey (TÜBİTAK)

The binaural masking level difference (BMLD) is an auditory phenomenon where binaural tone-in-noise detection is improved when the phase of either signal or noise is inverted in one of the ears (SπNo or SoNπ, respectively), relative to detection when signal and noise are in identical phase at each ear (SoNo). Processing related to BMLDs and interaural time differences has been confirmed in the auditory brainstem of non-human mammals; in the human auditory brainstem, phase-locked neural responses elicited by BMLD stimuli have not been systematically examined across signal-to-noise ratio. Behavioral and physiological testing was performed in three binaural stimulus conditions: SoNo, SπNo, and SoNπ. BMLDs at 500 Hz were obtained from 14 young, normal-hearing adults (ages 21–26). Physiological BMLDs used the frequency-following response (FFR), a scalp-recorded auditory evoked potential dependent on sustained phase-locked neural activity; FFR tone-in-noise detection thresholds were used to calculate physiological BMLDs. FFR BMLDs were significantly smaller (poorer) than behavioral BMLDs, and FFR BMLDs did not reflect a physiological release from masking, on average. Raw FFR amplitude showed substantial reductions in the SπNo condition relative to SoNo and SoNπ conditions, consistent with negative effects of phase summation from left and right ear FFRs. FFR amplitude differences between stimulus conditions (e.g., SoNo amplitude–SπNo amplitude) were significantly predictive of behavioral SπNo BMLDs; individuals with larger amplitude differences had larger (better) behavioral B MLDs and individuals with smaller amplitude differences had smaller (poorer) behavioral B MLDs. These data indicate a role for sustained phase-locked neural activity in BMLDs of humans and are the first to show predictive relationships between behavioral BMLDs and human brainstem responses.

The Binaural Masking-Level Difference phenomenon occurs both in listeners with normal hearing and with sensorineural hearing loss (SNHL). Previous studies of BMLDs involving SNHL listeners used a 500- or 2000-Hz pure tone as the target signal, but the BMLD performance of SNHL listeners with stimulus amplified for other frequencies has not been reported previously. Therefore, this study aimed to measure the BMLD in SNHL listeners at various frequencies after amplification by hearing aids. Thirty subjects with mild to moderately severe SNHL participated in the experiments. The BMLDs were measured based on the detection threshold differences for pure tones of 125, 250, 500, 1000, and 2000 Hz in the presence of white noise when presented interaurally in phase (S0N0) and interaurally in antiphase (SπN0). The results show that when using white noise as a masker, the average detection thresholds for the target signals were significantly lower in the SπN0 condition compared to those in the S0N0 condition (p

RESUMO Objetivo Pesquisar a habilidade auditiva de atenção seletiva na população escolar e identificar valores de referência para a faixa etária de sete a dez anos por meio do teste Masking Level Difference, além de identificar se a escolaridade dos pais, bem como a renda familiar, pode influenciar os resultados do teste. Método Participaram do estudo 31 escolares que se encaixaram nos critérios de elegibilidade da pesquisa, sendo 20 do gênero feminino e 11 do gênero masculino. Realizou-se anamnese para questionamento da renda familiar e escolaridade dos pais do escolar, inspeção visual do meato acústico externo, audiometria tonal liminar, logoaudiometria, medidas de imitância acústica, teste Dicótico de Dígitos e teste Masking Level Difference. Resultados A idade média dos indivíduos foi de 8,67 anos. Não foi observada diferença entre os gêneros e entre as idades avaliadas, no desempenho do MLD. Não houve relação entre a escolaridade dos pais e a renda mensal média com o desempenho das crianças no MLD. A média do MLD foi de 7,65 dB, com desvio padrão de 2,51 dB. Conclusão O Masking Level Difference em escolares de sete a dez anos é de 7,65 dB e independe do gênero, do nível de escolaridade dos pais ou da renda mensal média da família do escolar. ABSTRACT Purpose To investigate the auditory ability of selective attention in the school population and to identify reference values to the age group from seven to ten years old through the Masking Level Difference Test, and to identify if the parents’ schooling, as well as the family income can influence the test results. Methods Thirty-one schoolchildren who match the eligibility criteria attended the study, being 20 female and 11 male. An anamnesis was conducted to question the familiar income and the schooling of the children´s parents; we also performed visual inspection of the External Acoustic Meatus, Pure Tone Audiometry, Speech Audiometry, Acoustic Immittance Measures, Dichotic Digits Test and Masking Level Difference test. Results The mean age of the individuals was 8.67 years. There were no observed differences between genders and between the evaluated ages in the MLD performance. There was no relation between the parents’ schooling and the average monthly income with the performance of the children in MLD Test. The MLD mean was 7.65 dB and standard deviation of 2.51 dB. Conclusion The Masking Level Difference in schoolchildren from seven to ten years old is 7.65 dB and is independent of the gender, parents’ schooling and the average monthly income of the schoolchild.

Background and objectives In clinical masking, the plateau is a state in which the non-test ear (NTE) is completely masked by the noise and tone is heard only by the test ear (TE). At least 15 to 20 dB of plateau width is needed to obtain valid threshold. In the study, a part of plateau after initial masking level known as the minimum plateau width (mPW) was determined and compared by a new formula and the plateau searching method. Subjects and. Methods Minimum plateau widths of air conduction were obtained in 29 participants with unilateral and 30 participants with bilateral conductive hearing loss (CHL) aged 20 to 45 years old by using step by step plateau method and mPW estimation by the formula between two points of masking diagram [mPW=(N2-N1)-(T2-T1)] and then the mPW of two methods was compared for each frequency. Results There was no significant difference between the minimum plateau width obtained by the plateau and formula methods for two given point of masking diagram in people with unilateral and bilateral CHL at octave frequencies from 500 Hz to 4,000 Hz. Conclusions Threshold obtaining of TE by two tones for two noise levels delivered to the NTE is enough to estimate the mPW between these two noise points and it is not necessary that for clinicians to know the actual values of masking diagram components.

Although several studies have examined the relationship between high-frequency pure-tone thresholds and the 500-Hz binaural masking level difference (BMLD), the results have not always been consistent. In this study, a retrospective analysis was conducted on an existing dataset from over 3000 military service members that included both pure-tone thresholds measured as part of their annual hearing conservation testing and a 33-trial clinical test of the BMLD. There was only a slight dependence of the 500-Hz BMLD on high-frequency pure-tone thresholds. For listeners with elevated pure-tone thresholds, this dependence was in good agreement with the findings of Jerger et al. [Arch. Otolaryngol. 110, 290–296 (1984)] and slightly larger than that reported by Wilson and Weakley [J. Am. Acad. Audiol. 16, 367–382 (2005)]. For listeners with near-normal hearing, the dependence of the 500-Hz BMLD on the 4-kHz pure-tone threshold was substantially less than that reported by Bernstein and Trahiotis [J. Acoust. Soc. Am. 140, 3540–3548 (2016)]. A possible explanation might be the degree of training offered to the subjects and procedural differences between clinical and laboratory techniques. [The views expressed in this abstract are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government.] Although several studies have examined the relationship between high-frequency pure-tone thresholds and the 500-Hz binaural masking level difference (BMLD), the results have not always been consistent. In this study, a retrospective analysis was conducted on an existing dataset from over 3000 military service members that included both pure-tone thresholds measured as part of their annual hearing conservation testing and a 33-trial clinical test of the BMLD. There was only a slight dependence of the 500-Hz BMLD on high-frequency pure-tone thresholds. For listeners with elevated pure-tone thresholds, this dependence was in good agreement with the findings of Jerger et al. [Arch. Otolaryngol. 110, 290–296 (1984)] and slightly larger than that reported by Wilson and Weakley [J. Am. Acad. Audiol. 16, 367–382 (2005)]. For listeners with near-normal hearing, the dependence of the 500-Hz BMLD on the 4-kHz pure-tone threshold was substantially less than that reported by Bernstein and Trahiotis [J. Acoust. Soc. Am...

PurposeThe purpose of the present study was to examine individual differences in binaural processing across the adult life span.MethodSixty listeners (aged 23–80 years) with symmetrical hearing were tested. Binaural behavioral processing was measured by the Words-in-Noise Test, the 500-Hz masking level difference, and the Dichotic Digit Test. Electrophysiologic responses were assessed by the auditory middle latency response binaural interaction component.ResultsNo correlations among binaural measures were found. Age accounted for the greatest amount of variability in speech-in-noise performance. Age was significantly correlated with the Words-in-Noise Test binaural advantage and dichotic ear advantage. Partial correlations, however, revealed that this was an effect of hearing status rather than age per se. Inspection of individual results revealed that 20% of listeners demonstrated reduced binaural performance for at least 2 of the binaural measures.ConclusionsThe lack of significant correlations among variables suggests that each is an important measurement of binaural abilities. For some listeners, binaural processing was abnormal, reflecting a binaural processing deficit not identified by monaural audiologic tests. The inclusion of a binaural test battery in the audiologic evaluation is supported given that these listeners may benefit from alternative forms of audiologic rehabilitation.

The method of mathematical modeling of object type "perspective mobile radio system of military – designation - operational area - system of enemy radio reconnaissance", which solves the problem of creating a mathematical model of this object to research level radio masking and which can be used as a basis for the development of algorithmic support of decentralized management system - communication system, in particular the management of radio masking level has been presented in the article.

The current study compared the effectiveness of masking on recognition performance for faces and voices of celebrities and personally familiar individuals. On the basis of the theory suggesting stronger memory representations for personally familiar individuals, we expected masking to be more effective for celebrities than for personally familiar stimulus persons. Furthermore, we sought to replicate the face recognition advantage with masked stimuli. Face pixelation and electronic changes of the voice pitch were applied as masking techniques, using four masking levels for each stimulus. Thirty-one undergraduate students were presented with the masked faces and voices of 10 celebrities and 10 personally familiar fellow students. As expected, more correct recognitions occurred for faces than for voices, suggesting that masking does not counteract the mechanisms causing the face recognition advantage. Unexpectedly, masking effectiveness did not differ between celebrities and personally familiar individuals. This may be due to the type of personally familiar individuals used. Within personally familiar stimuli, increased familiarity did not predict the effectiveness of masking. Whereas the highest masking level eliminated speaker recognition, masking did not fully eliminate face recognition. From a practical perspective, the findings especially question the suitability of pixelation as a means for identity concealment.

Speech recognition in a complex masker usually benefits from masker harmonicity, but there are several factors at work. The present study focused on two of them, glimpsing spectrally in between masker partials and periodicity within individual frequency channels. Using both a theoretical and an experimental approach, it is demonstrated that when inharmonic complexes are generated by jittering partials from their harmonic positions, there are better opportunities for spectral glimpsing in inharmonic than in harmonic maskers, and this difference is enhanced as fundamental frequency (F0) increases. As a result, measurements of masking level difference between the two maskers can be reduced, particularly at higher F0s. Using inharmonic maskers that offer similar glimpsing opportunity to harmonic maskers, it was found that the masking level difference between the two maskers varied little with F0, was influenced by periodicity of the first four partials, and could occur in low-, mid-, or high-frequency regions. Overall, the present results suggested that both spectral glimpsing and periodicity contribute to speech recognition under masking by harmonic complexes, and these effects seem independent from one another.

Tinnitus characteristics in normal-hearing patients differ between the groups with unilateral and bilateral complaints.The study was to determine the differences between tinnitus characteristics observed in patients with unilateral vs bilateral symptoms and normal hearing threshold, as well as normal results of distortion-product otoacoustic emissions (DPOAEs).The patients answered questions concerning tinnitus duration, laterality, character, accompanying symptoms, and circumstances of onset. The results of tympanometry, auditory brainstem responses, tinnitus likeness spectrum, minimum masking level (MML), and uncomfortable loudness level were evaluated. Records of 380 tinnitus sufferers were examined. Patients with abnormal audiograms and/or DPOAEs were excluded. The remaining 66 participants were divided into groups with unilateral and bilateral tinnitus.Unilateral tinnitus in normal-hearing patients was diagnosed twice more frequently than bilateral. Tinnitus pitch was higher in the group with bilateral tinnitus (p .001). MML was lower in unilateral tinnitus (p .05). Mean age of patients was higher in the unilateral tinnitus group (p .05). Mean tinnitus duration was longer (p .05) and hypersensitivity to sound was more frequent (p .05) in the bilateral tinnitus group. Repeated exposure to excessive noise was the most frequent cause in the bilateral tinnitus group.

Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs.

Binaural masking patterns show a steep decrease in the binaural masking-level difference (BMLD) when masker and signal have no frequency component in common. Experimental threshold data are presented together with model simulations for a diotic masker centered at 250 or 500 Hz and a bandwidth of 10 or 100 Hz masking a sinusoid interaurally in phase (S(0)) or in antiphase (S(π)). Simulations with a binaural model, including a modulation filterbank for the monaural analysis, indicate that a large portion of the decrease in the BMLD in remote-masking conditions may be due to an additional modulation cue available for monaural detection.

Early detection of non-organic hearing loss (NOHL) is important in order to ensure appropriate management decisions. One possible audiometric test for achieving this is the tone-in-noise (TIN) test although its current format is not widely applicable and may not optimize accuracy. We sought to investigate a modified TIN test, using narrowband noise, and the influence of different noise levels and alternative approaches to determining the outcome. Seventy-five normal-hearing and 8 hearing-impaired subjects were asked to feign or exaggerate a hearing loss. The shift in genuine or exaggerated/feigned thresholds with the introduction of ipsilateral noise was determined. The TIN test was able to accurately separate between genuine and feigned thresholds when using narrowband noise presented at the effective masking level corresponding to the apparent tone threshold and using a 'fail' criterion of a repeatable threshold shift of ≥ 10 dB at one or more frequencies. It also produced similar shifts in exaggerated thresholds. In conclusion, this modified TIN test is a potentially accurate method to rapidly identify unilateral and bilateral NOHL in a wide range on contexts and could be applied to automated audiometry.

The aim of the present research was to investigate central auditory functioning in normal-hearing, solvent-exposed subjects compared to normal-hearing subjects without solvent exposure, with a comprehensive test battery of behavioural central auditory functioning procedures. Study sample: Forty-six normal-hearing, solvent-exposed subjects and 46 normal-hearing, control subjects were selected to participate in the study. Design: All subjects must present with normal hearing thresholds and absence of history of variables related to the onset of auditory dysfunction. Subjects were evaluated with a test battery comprising pure-tone audiometry (PTA), dichotic digits (DD), pitch pattern sequence (PPS), fi ltered speech (FS), random gap detection (RGD), masking level difference (MLD), and hearing-in-noise (HINT) tests. Results: Analyses of covariance (ANCOVA) were performed to compare the mean values of the dependent variables (results for DD, PPS, FS, RGD, MLD, and HINT) between solvent-exposed and control subjects. Age and average hearing thresholds (500 - 8000 Hz) were included in the analyses as covariates. Signifi cant differences for DD, PPS, FS, and RGD results were found between groups. Conclusion: This study provides further evidence of the central auditory dysfunction associated with solvent exposure.

The levels of noise necessary to effectively mask the stimuli commonly used in auditory brainstem response (ABR) tests were determined. The relative masking level (RLM) of twenty normally-hearing volunteers was measured behaviourally using ipsilaterally presented unfiltered noise in the presence of ABR stimuli. The upper limit for RLM was found to be typically 30 dB above the stimulus level when the stimulus was calibrated in dBnHL to ISO 389-6 (2007) and the noise was measured in dBSPL. This value is recommended when calculating the level of noise necessary to prevent cross-hearing during ABR testing.

Item does not contain fulltext The aims of the study were to investigate whether sound localization acuity improved when children with 1 cochlear implant use a hearing aid in the contralateral ear (bimodal fitting), and whether this enabled them to benefit from a binaural masking level difference. Four different noise bursts were used as stimuli for a minimal audible angle localization test. On average, localization acuity remained poor with the cochlear implant alone, but also with bimodal fitting. A significant benefit of bimodal fitting was only shown when the most complicated stimulus with roved amplitude and spectrum was presented (minimal audible angle of 151 degrees with bimodal fitting vs. 175 degrees with cochlear implant alone). No significant binaural masking level difference was found between the cochlear implant alone and the bimodal condition.

Despite its incidence, there are still few reports in literature relating to tinnitus in children. Almost all data were collected by means of questionnaires or in a limited population of children. In order to collect data in a homogeneous way and directly from the patients, the protocol of study proposed by Savastano has been applied to 1,100 children. The results showed tinnitus as present in 374 children but only 6.5% of the cases complained spontaneously about it. In all, 76.4% of the children demonstrated normal hearing, whereas 64.5% reported being bothered by their tinnitus. Tinnitus measurements were obtained and are reproducible in all patients older than 8 years of age. The loudness level was

The masking level difference (MLD) is a psychoacoustic measure of binaural interaction and central auditory processing related to extracting signals from noise backgrounds. It represents the improvement in threshold sensitivity under antiphasic listening conditions relative to homophasic conditions. A low frequency pure tone (500 Hz) was presented in-phase (So) binaurally to the subject in the presence of a phasic masker (No). The behavioural threshold obtained at this condition was used as a reference. The behavioural threshold was again determined with the pure tone stimulus presented antiphasically (S), and the difference in thresholds was calculated to determine the MLD. The MLD was measured for a 500 Hz pure tone in 36 Aboriginal children (16 males and 20 females) from an Aboriginal community school (Nguiu, Tiwi Islands) where conductive hearing loss, due to otitis media, is endemic. The control group consisted of 62 normal-hearing children (40 males and 22 females) from a private school in Darwin. Aboriginal children showed a mean MLD of 7.76 dB whereas the control group exhibited a mean MLD of 11.21 dB. Aboriginal children showed a consistently lower MLD than non-Aboriginal normal-hearing children. Auditory processing disorders (APDs) have been shown to be related to early auditory deprivation, a common feature of chronic conductive hearing loss observed frequently in Aboriginal children. Thus, the MLD provides a metric for assessing binaural hearing abilities which may be relevant to the assessment of APD and hearing aid fitting. The MLD is a less linguistically, less culturally biased predictive measure and may be more easily administered than many speech and language test procedures used in diagnosing APD.

Although tinnitus is a major health problem, techniques to quantify its perceptual aspects are not standardized. This study represents a key step in our efforts to develop clinical methodology to accurately and reliably quantify the sensation of tinnitus, using a uniform method for obtaining a battery of tinnitus measures.The purpose of this study was to evaluate the performance of the automated system, which was redesigned to reduce time of testing and to add new testing capabilities. The primary difference in function was the use of a 'knob' device that enabled patient control of auditory stimuli. The new tests included assessment of minimum masking level (MML) and residual inhibition (RI).As with previous iterations of the system, a computer program ran all testing and subjects read instructions and provided responses via a computer touch-screen. Three separate studies were conducted. Study 1 evaluated within- and between-session test-retest response reliability of tinnitus loudness matches (LMs) and pitch matches (PMs). Study 2 was conducted to evaluate differences in LMs and PMs between subjects with and without tinnitus - to obtain pilot data to assist in the development of a test for 'tinnitus malingering.' Study 3 evaluated the system's capability of obtaining MMLs and RI as well as the between-session reliability of these measures.Study 1 documented that the new system could obtain LMs and PMs within approximately 20 min, while maintaining clinically acceptable reliability. Study 2 revealed characteristic differences in LM and PM test results for individuals who did not experience tinnitus. Study 3 documented the system's ability to obtain measures of MML and RI that were reliable across sessions.

Detection thresholds for tones in narrow-band noise were measured for two binaural configurations: N(o)S(o) and N(o)S(pi). The 30-Hz noise band had a mean overall level of 65 dB SPL and was centered on 250, 500, or 5000 Hz. Signals and noise were simultaneously gated for 500, 110, or 20 ms. Three conditions of level randomization were tested: (1) no randomization; (2) diotic randomization--the stimulus level (common to both ears) was randomly chosen from an uniformly distributed 40-dB range every presentation interval; and (3) dichotic randomization--the stimulus levels for each ear were each independently and randomly chosen from the 40-dB range. Regardless of binaural configuration, level randomization had small effects on thresholds at 500 and 110 ms, implying that binaural masking-level differences (BMLDs) do not depend on interaural level differences for individual stimuli. For 20-ms stimuli, both diotic and dichotic randomization led to markedly poorer performance than at 500- and 110-ms durations; BMLDs diminished with no randomization and dichotic randomization but not with diotic randomization. The loss of BMLDs at 20 ms, with degrees-of-freedom (2WT) approximately 1, implies that changes in intracranial parameters occurring during the course of the observation interval are necessary for BMLDs when mean-level and mean-intracranial-position cues have been made unhelpful.

The purpose of this study was to determine if performances on a 500 Hz MLD task and a word-recognition task in multitalker babble covaried or varied independently for listeners with normal hearing and for listeners with hearing loss. Young listeners with normal hearing (n = 25) and older listeners (25 per decade from 40–80 years, n = 125) with sensorineural hearing loss were studied. Thresholds at 500 and 1000 Hz were ≤30 dB HL and ≤40 dB HL, respectively, with thresholds above 1000 Hz

Adults and children (aged 5 years 1 month to 10 years 8 months) were tested in a masking-level difference (MLD) paradigm in which detection of brief signals was contrasted for signal placement in masker envelope maxima versus masker envelope minima. Maskers were 50-Hz-wide noise bands centered on 500 Hz, and the signals were So or Sπ 30-ms, 500-Hz tones. In agreement with previous studies, it was found that MLDs were greater for masker envelope minima placement than for masker envelope maxima placement. Across the age range of the children tested here, the binaural advantage associated with the masker envelope minima increased with the age of the child. One interpretation of the present results is that there is a developmental improvement in binaural temporal resolution over the age range tested here.

The behavioral binaural masking level difference (BMLD) is believed to reflect brain stem processing. However, this conflicts with transient auditory evoked potential research that indicates the auditory brain stem and middle latency responses do not demonstrate the BMLD. The objective of the present study is to investigate the brain stem and cortical mechanisms underlying the BMLD in humans using the brain stem and cortical auditory steady-state responses (ASSRs).A 500-Hz pure tone, amplitude-modulated (AM) at 80 Hz and 7 (or 13) Hz, was used to elicit brain stem and cortical ASSRs, respectively. The masker was a 200-Hz-wide noise centered on 500 Hz. Eleven adult subjects with normal hearing were tested. Both ASSR (brain stem and cortical) and behavioral thresholds for diotic AM stimuli (when the signal and noise are in phase binaurally: SoNo) and dichotic AM stimuli (when either the signal or noise is 180 degrees out-of-phase between the two ears: SpiNo, SoNpi) were investigated. ASSR and behavioral BMLDs were obtained by subtracting the threshold for the dichotic stimuli from that for the diotic stimuli, respectively. Effects for modulation rate, signal versus noise phase changes, and behavioral versus ASSR measure on the BMLD were investigated.Behavioral BMLDs (mean = 8.5 to 10.5 dB) obtained are consistent with results from past research. The ASSR results are similar to the pattern of results previously found for the transient auditory brain stem responses and the N1-P2 cortical auditory evoked potential, in that only the cortical ASSRs (7 or 13 Hz) demonstrate BMLDs (mean = 5.8 dB); the brain stem ASSRs (80 Hz) (mean = 1.5 dB) do not. The ASSR results differ from the previous transient N1-P2 studies, however, in that the cortical ASSRs show a BMLD only when there is a change in the signal interaural phase, but not for changes of noise interaural phase.Results suggest that brain processes underlying the BMLD occur either in a different pathway or beyond the brain stem auditory processing underlying the 80-Hz ASSR. Results also suggest that the cortical ASSRs have somewhat different neural sources than the transient N1-P2 responses, and that they may reflect the output of neural populations that previous research has shown to be insensitive to binaural differences in noise.

Previous data on the masking level difference (MLD) have suggested that NoSpi detection for a long-duration signal is dominated by signal energy occurring in masker envelope minima. This finding was expanded upon using a brief 500-Hz tonal signal that coincided with either the envelope maximum or minimum of a narrow-band Gaussian noise masker centered at 500 Hz, and data were collected at a range of masker levels. Experiment 1 employed a typical MLD stimulus, consisting of a 30-ms signal and a 50-Hz-wide masker with abrupt spectral edges, and experiment 2 used stimuli generated to eliminate possible spectral cues. Results were quite similar for the two types of stimuli. At the highest masker level the MLD for signals coinciding with masker envelope minima was substantially larger than that for signals coinciding with envelope maxima, a result that was primarily due to decreased NoSpi thresholds in masker minima. For most observers this effect was greatly reduced or eliminated at the lowest masker level. These level effects are broadly consistent with the presence of physiological background noise and with a level-dependent binaural temporal window. Comparison of these results with predictions of a published model suggest that basilar-membrane compression alone does not account for this level effect.

Abstract In this study, we examined the effect of contralateral masking on cortical auditory evoked potentials N1 (modal-specific slowly adapting component) and P2 at different masking intensities. N1 and P2 potentials were recorded from 15 subjects with normal hearing using 500Hz tone pips (intensity 65dB HL, duration 100ms, ISI 1s) presented to the right ear. Continuous white noise was delivered to the left ear at the intensities of 35, 50, 65, or 75dB effective masking level (EML), as well as a no-mask condition. The electrodes F3, Fz, F4, C3, Cz, C4, and Pz were used. The results show that N1 amplitude was significantly attenuated and, in contrast, P2 amplitude was significantly increased, with contralateral 75dB EML white noise. N1P2 peak to peak amplitude was not affected by masking, nor were the peak latencies. Thus, contralateral masking affects the exogenous cortical evoked N1 and P2 curves differently. We suggest that the effect is mediated by the efferent hearing system. The effect of ≤ 50dB EML contralateral white noise masking is so small that it should not affect clinical recordings.

The purpose of this series of experiments was to develop a simple, 500-Hz masking-level difference (MLD) protocol that could be implemented easily in the clinic to assess auditory perceptual abilities using an audio compact disc. Five, 300-ms tones with 250-ms intertone intervals were embedded in 3-s bursts of 200-800 Hz noise presented at 42.2-dB pressure-spectrum level with 4-5 s inter-stimulus intervals. The homophasic and antiphasic conditions were interleaved with the signal-to-noise ratios decreasing in 2-dB steps. A single-interval, "yes/no" response task was used. Three experiments were performed on 24-28 listeners with normal hearing. The mean SoNo thresholds (58.1- to 59.5-dB SPL) and the mean SπNo thresholds (45.1- to 46.0-dB SPL) produced ˜13-dB MLDs. Experiment 3 included a SoNπ condition that had a mean threshold of 48.8-dB SPL and a 10.0-dB MLD. The mean test, retest ot the SoNo and SπNo thresholds on 15 listeners was

In binaural tone-in-noise detection experiments humans can achieve substantially lower thresholds if either noise or tone have interaural time or phase differences (ITDs / IPDs) compared to diotic presentation of tone and noise. This effect is named binaural masking level difference (BMLD) and was mainly investigated at 500 Hz. The results obtained in these experiments were used to fit binaural processing errors in the equalization-cancelation (EC) mechanism, which is an effective model of binaural processing. In this study, the frequency dependency of BMLDs is investigated for listeners with normal hearing and high frequency hearing loss. Binaural tone-in-noise detection experiments are conducted for tone frequencies of 250, 500, 750, 1000, 1500, and 2000 Hz, and ITDs of the noise up to 5 times the period of the tested frequency. Furthermore, diotic and dichotic speech reception thresholds for low pass filtered speech in noise are measured with the same listeners. The EC mechanism with processing errors ...

Objectives:The difficulty in choosing appropriate therapy for chronic tinnitus lies in its various forms of impact on the quality of life of patients and requires personalization. The aim of the study was to evaluate the efficacy of the use of sound generators with individual adjustments to relieve tinnitus in patients unresponsive to previous drug treatment.Methods:This was a prospective study of 10 patients, 5 male and 5 female, ages ranging from 41 to 78 years with chronic tinnitus who were resistant to previous drug treatments. Bilateral sound generators Reach62 or Mind 9 models were used for at least 6 daily hours for 18 months. Audiometrics testing, pitch, loudness, minimum masking level (MML), Tinnitus Handicap Inventory (THI), Visual Analogue Scales (VAS), and Hospital Anxiety and Depression Scale (HADS) questionnaires were given. Sound generators were used before 1 month and, sequentially every 3 months up to 18 months. The sound generators were individually adjusted, according to criteria of per...

Objetivo caracterizar o processamento auditivo de escolares que falharam na avaliação simplificada do processamento auditivo e comparar esses achados com os resultados na avaliação comportamental do processamento auditivo. Métodos realizou-se a avaliação audiológica básica (audiometria tonal e vocal e medidas de imitância acústica), bateria comportamental do processamento auditivo composta pelos testes PSI (Pediatric Speech Intelligibility) versão em português, PPS (Pitch Pattern Sequence), MLD (Masking Level Difference), SSW (Stagged Spondaic Words) versão em português e GIN (Gap in Noise) e reteste da avaliação simplificada do processamento auditivo com escolares de 9 a 14 anos, matriculados entre o 4º ano e a 8ª série do ensino fundamental de uma escola de ensino público de Porto Alegre. Resultados dos 11 escolares avaliados que falharam na avaliação simplificada, 10 (90,9%) apresentaram alterações na bateria comportamental do processamento auditivo. Os subperfis com maior número de alterações foram os de decodificação e integração, as habilidades auditivas mais prejudicadas foram de interação binaural e separação e integração binaural concomitantemente. Não houve associação significante entre as tarefas da avaliação simplificada e os testes da bateria comportamental ao comparar o mesmo correlato neurofisiológico ou tarefa semelhante. Conclusão foi possível caracterizar o processamento auditivo dos escolares avaliados. A partir da comparação entre a avaliação simplificada e a bateria comportamental verificou-se que a avaliação simplificada pode ser um preditor sensível às alterações de processamento auditivo, apesar de não se identificar associação específica entre as habilidades comparadas. Purpose to characterize the auditory processing of students who failed in the simplified evaluation of the auditory processing and compare these found results with the results in the behavioral auditory processing evaluation. Methods it was performed the basic audiological evaluation (vocal and tonal audiometry and acoustic immitance measurements), the behavioral battery of the auditory processing, composed by the PSI (Pediatric Speech Intelligibility) portuguese version, PPS (Pitch Pattern Sequence), MLD (Masking Level Difference), SSW (Stagged Spondaic Words) portuguese version and GIN (Gap in Noise), and the retest of the simplified evaluation of the auditory processing with students from nine to fourteen years old registered between 4th to 8th grade of a public school in Porto Alegre. Results ten (90,9%) out of the eleven evaluated students that failed in the simplified evaluation showed alterations in the behavioral battery of auditory processing tests. The subprofiles which had the major number of alterations were the ones of decoding and integration, the most impaired auditory abilities were binaural interaction and separation and binaural integration concomitantly. There was no relevant association between the tasks of the simplified evaluation and the tests of the behavioral battery when comparing the same neuralphisiological report or similar task. Conclusion it was possible to characterize the auditory processing of the analyzed students. From the comparison between the simplified evaluation and the behavioral battery it was noted that the simplified evaluation can be a sensible predictor to the alterations of the auditory processing, in spite of not identifying the specific association between the compared abilities.

Objectives To assess the safety and efficacy of multiple sessions of electrostimulation by a transtympanic needle electrode on the promontory for tinnitus relief. Study design Prospective open, unblinded, uncontrolled clinical trial. Setting Tertiary academic referral center. Patients Ten patients (8 male and 2 female subjects), mean age 50.1 ± 12 years (range, 34-67) with severe unilateral tinnitus completed all stages of the study. Patients with tinnitus duration between 6 months to 3 years were included. Intervention The patients underwent 3 consecutive 30-minute sessions, every other day, of biphasic, charge balanced electrostimulation pulses to the promontory delivered by a transtympanic needle electrode. Main outcome measures 1) Tinnitus loudness reported by visual analog scale (VAS) between 1 and 10, at baseline, before and after each treatment, and 1, 2, 3, and 4 weeks after the last treatment. 2) Tinnitus Handicap Inventory (THI) questionnaire at baseline and 4 weeks after treatment. 3) Basic audiometry and tinnitus specific tests such as minimum masking level, tinnitus loudness, and pitch. Results No long-term adverse safety outcomes were noted in physical examination or audiologic evaluation. VAS levels decreased by ≥2 levels in 5 patients (50%) and returned to baseline 4 weeks after treatment. The VAS decrease was found significant (p = 0.048) in those patients. A statistically significant decrease in THI score was noted 4 weeks after treatment. Tinnitus specific tests at that time were unchanged from baseline. Conclusion Multiple sessions of electrostimulation to the promontory seem to be safe and may be beneficial for some tinnitus patients. Further clinical trials are warranted.

Bilateral fittings of bone-anchored hearing aids (BAHA) were evaluated in 25 patients with at least 3 months experience with using two BAHAs. For all patients, air conduction hearing aids were contraindicated due to either recurrent otorrhoea or otitis externa (19 cases) or to congenital aural atresia (six cases). Candidacy for bilateral fitting was primarily based on symmetry of bone conduction thresholds. For all patients, measurements comprised sound localisation, speech recognition in quiet and in noise. In addition, in a subgroup of nine patients, release from masking for pure-tone stimuli in noise with interaural phase differences (binaural masking level difference, BMLD) was measured. The percentage of correct localisation judgments with 500-Hz and 2-kHz noise bursts increased significantly (p

The role of harmonicity in masking was studied by comparing the effect of harmonic and inharmonic maskers on the masked thresholds of noise probes using a three-alternative, forced-choice method. Harmonic maskers were created by selecting sets of partials from a harmonic series with an 88-Hz fundamental and 45 consecutive partials. Inharmonic maskers differed in that the partial frequencies were perturbed to nearby values that were not integer multiples of the fundamental frequency. Average simultaneous-masked thresholds were as much as 10 dB lower with the harmonic masker than with the inharmonic masker, and this difference was unaffected by masker level. It was reduced or eliminated when the harmonic partials were separated by more than 176 Hz, suggesting that the effect is related to the extent to which the harmonics are resolved by auditory filters. The threshold difference was not observed in a forward-masking experiment. Finally, an across-channel mechanism was implicated when the threshold difference was found between a harmonic masker flanked by harmonic bands and a harmonic masker flanked by inharmonic bands. A model developed to explain the observed difference recognizes that an auditory filter output envelope is modulated when the filter passes two or more sinusoids, and that the modulation rate depends on the differences among the input frequencies. For a harmonic masker, the frequency differences of adjacent partials are identical, and all auditory filters have the same dominant modulation rate. For an inharmonic masker, however, the frequency differences are not constant and the envelope modulation rate varies across filters. The model proposes that a lower variability facilitates detection of a probe-induced change in the variability, thus accounting for the masked threshold difference. The model was supported by significantly improved predictions of observed thresholds when the predictor variables included envelope modulation rate variance measured using simulated auditory filters.