Articles in Press

Review Article(s)

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    Background and aim: Air pollution has a negative impact on various body systems, including auditory system. The aim of this study was to provide a comprehensive review of research investigating the effects of air pollution on various levels of the auditory system, including peripheral and central components, as well as related cognitive processing and associated disorders.
    Recent finding: Air pollution includes a diverse and complex mixture of chemicals, particulate matter or biological substances in ambient air. Air pollution can be harmful to humans and other living things. It has become a major environmental concern in recent decades, especially in developing and industrialized countries. There is a lot of evidence showing that air pollution can harm different parts of the body, like the lungs, heart, brain, and ears. Hearing loss is the second most common non-infectious disorder, and its effects can lead to serious issues in communication, speech, language, education, social interactions, finances, and mental well-being.
    Conclusion: This study examines various research studies that link air pollution to hearing problems, highlighting how air pollutants can harm different aspects of the auditory system.

Research Article(s)

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    Background and Aim: Deaf individuals in India face significant auditory impairment, leading to challenges in accessing services. Studies highlight the need to enhance communication services and accessibility to ensure fair access to resources for the deaf community. The present study aimed to address the barriers faced by deaf individuals while availing speech and hearing services in India.
    Methods: A total of 325 deaf individuals were considered in the age range of 18–30 years, and a survey research design was employed. A 25-item questionnaire was developed under three domains: communication barriers, service access barriers, and psychological barriers. The questionnaires were given to the participants to fill, and the responses were calculated.
    Results: The overall results revealed that service access barriers were more compared to communication barriers and psychological barriers. In services-related barriers, the results revealed communication barriers, 74% of the participants preferred sign language during speech and hearing consultations and required counselling by professionals in sign language. Further, in terms of psychological barriers, 70% of participants lacked confidence in visiting speech and hearing institutes/clinics. Moreover, 78.8% of participants reported a need for more materials in sign language at the appointment sections and a lack of sign language interpreters while accessing services in terms of service access barriers.
    Conclusion: Addressing these barriers faced by deaf individuals is critical to ensure equitable access to services and promote positive experiences while they are availing speech and hearing services.

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    Background and Aim: Structural and functional changes in the auditory and cognitive system caused by aging can lead to impaired speech perception and speed processing, especially in the presence of noise. This study aimed to enhance cognitive system performance including speed processing and speech perception by improving the temporal information through lateralization training.
    Methods: In this interventional study, 36 participants aged 65–75 years with normal hearing, who complained about speech perception in noise, were randomly assigned to the intervention group and the control group. The intervention group received twelve 45-minute sessions of auditory lateralization training. The quick speech-in-noise, words-in-noise, and consonant-vowel-in-noise tests are used as behavioral tests of speech perception in noise at the sentence, word and phoneme levels, respectively. The time-compressed speech test was adopted to measure processing speed. The repeated measures ANOVA was used to analyze the test results before, after, and one month after rehabilitation.
    Results: A significant decrease in the lateralization errors, and signal-to-noise ratio loss in both the quick speech-in-noise and words-in-noise tests were observed in the intervention group (p<0.001). Moreover, a considerable increase in the word recognition score in the time-compressed speech test and the consonant-vowel in noise test were observed (p<0.001). Coefficient effects were obtained for the quick speech-in-noise test (0.74), the words-in-noise test (0.59) and the consonant-vowel in noise test (0.12). Statistical analyses revealed the stability of the outcomes one month after rehabilitation.
    Conclusion:  Auditory lateralization training can improve the speed of processing and speech perception in noise in the elderly.

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    Background and Aim: Motion sickness is common during various forms of transportation. The Motion Sickness Susceptibility Questionnaire-Short form (MSSQ-Short) is a self-report tool designed to assess this problem. This study aimed to translate and evaluate the psychometric properties of the Persian version of MSSQ-Short.
    Methods: The questionnaire was translated to Persian and culturally adapted as the P-MSSQ-Short. After confirming face validity, the P-MSSQ-Short was administered to 354 university students (274 non-pilots, 80 pilots). One hundred participants were categorized into low-, moderate-, and high-susceptibility groups based on their Numeric Rating Scale (NRS) scores. Construct, concurrent, and discriminant validity were assessed. Test-retest reliability was analyzed with 113 participants, along with measurements of Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), and Smallest Detectable Change (SDC).
    Results: The P-MSSQ-Short demonstrated good face validity. Total score showed strong correlations with sections A and B. Four factors were identified, with no ceiling effect but some floor effect observed. Scores significantly differed across NRS-based groups. The P-MSSQ-Short correlated strongly with NRS scores. Cronbach’s α for the total questionnaire, and sections A and B were 0.93, 0.88, and 0.86, respectively. Strong test-retest correlation was noted. ICCs for total, and sections A and B were 0.82–0.84. SEMs were 2.48, 2.15, and 4.29 while SDCs were 4.43, 4.18, and 5.65 for sections A, B, and total scores, respectively. Pilot students were significantly less susceptible than non-pilots (p<0.001).
    Conclusion: The P-MSSQ-Short exhibits high validity and reliability, making it a useful tool for predicting motion sickness susceptibility in Persian-speaking individuals.

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    Background and Aim: A Specific Learning Disability (SLD) is a neurological disorder thought to arise from dysfunctions within the central nervous system. Children with SLD often exhibit cognitive, linguistic, and auditory processing challenges, including deficits in binaural processing. Considering the overlapping elements of binaural processing and the areas evaluated by the Auditory Processing Domains Questionnaire (APDQ) —such as auditory, linguistic, and attentional skills —this study sought to examine the correlation between binaural listening, as measured by auditory tests, and the subscales of the APDQ in children with SLD.
    Methods: A sample of 20 children aged 8–12 years with diagnosed SLD was selected. The Persian version of the APDQ (APDQ-P) was used to assess some auditory processing, attention, and language skills. Binaural processing abilities were evaluated through Binaural Masking Level Difference (BMLD), Persian Auditory Recognition of Words in Noise (PARWIN) and three dichotic tests. Statistical analysis was conducted to investigate the correlation between APDQ-P scores and binaural processing test results.
    Results: A positive correlation was identified between the results of dichotic listening tests and APDQ-P scores. Specifically, the results of the left-ear competing sentence test showed a significant correlation with all the APDQ-P subscales.
    Conclusion: The study's results likely demonstrate the validity of the APDQ-P in representing dichotic listening skills. The findings of this study also highlight the significance of integrating both behavioral auditory tests and questionnaire-based evaluations to achieve a deeper understanding of how auditory behaviors, relate to the outcomes of binaural processing assessments in children with SLD.

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    Background and Aims: Tinnitus is a complex, multifactorial condition involving auditory and non-auditory systems. Individuals with bothersome tinnitus often report various associated problems, reflecting its diverse impact. This study aimed to evaluate the overall effect of tinnitus and correlate these findings with standard auditory measures using the International Classification of Functioning, Disability, and Health (ICF) framework.
    Methods: The study included 117 individuals with tinnitus (Mean age = 39.7 years, SD = 12.58; 52.1% female). Participants completed the Tinnitus Handicap Inventory (THI). Hyperacusis and misophonia were assessed using the Khalfa Hyperacusis Questionnaire and the Amsterdam Misophonia Scale-Revised. Retrospective data on pure-tone audiometry and speech identification scores were collected. Two open-ended questions—the Problem Effects Question and the Life Effects Question—were used to explore the impact of tinnitus on daily functioning and quality of life.
    Results: A total of 221 responses were collected for the Problem Effects Question and 140 for the Life Effects Question. Results showed that affected domains differed between the two questions: activity limitation was most prominent in the Problem Effects responses, while body function was most affected in the Life Effects responses.
    Conclusion: No significant correlations were found between ICF-based responses and auditory measures like pure-tone audiometry or speech identification scores. However, strong correlations were observed between the Problem Effects, Life Effects, and THI scores, emphasizing the importance of self-reported measures in understanding the impact of tinnitus.

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    Background and Aim: Speech perception in noise involves recognizing speech sounds. Given the importance of working memory in speech perception and the lack of an auditory Working Memory (WM) test in Persian with appropriate lexical load, this study aimed to validate the Persian version of the Word Auditory Recognition and Recall Measure (WARRM) in normal-hearing Persian speakers.
    Methods: The study involved two main stages: developing the Persian version and evaluating its validity and reliability. Participants included 59 monolinguals, Persian-speaking, normal-hearing college students aged 18–25 in Tehran, Iran, in 2023. Persian words were selected with the help of a linguistics expert based on phonetic and semantic features. Face and content validity were assessed by 10 experts. The WARRM test and the forward and backward digit span tests were administered. To assess the test-retest reliability, the test was performed by 30 participants at a 2-week interval and measured by the Intraclass Correlation Coefficient (ICC).
    Results: The WARRM test showed good face and content validity. The internal consistency was 0.72 for the overall test, 0.49 for the recognition subtest, 0.73 for the judgment subtest, and 0.87 for the recall subtest. The ICC values were 0.88 (overall), 0.89 (recall), and 0.48 (recognition). Significant positive correlations were found between the WARRM score and the scores of the forward digit span (r=0.65, p<0.001) and backward digit span (r=0.43, p<0.001).
    Conclusion: The Persian version of the abbreviated WARRM has good validity and reliability for use in clinical and rehabilitation studies on Persian speaker.

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    Background and Aim: Due to the annoying nature and prevalence of dizziness, vertigo, and imbalance, the need for rapid diagnosis, and challenges in the differential diagnosis of various vestibular disorders, this study  aimed to translate the dizziness symptom profile (DSP), which is a self-report tool that helps clinicians differentiate the most common vestibular system disorders, into the Persian language and evaluate its validity, reliability, sensitivity, and specificity.
    Methods: The profile was translated into Persian as DSP-P. Face, known-groups, and concurrent validities, internal consistency, test-retest reliability, sensitivity, and specificity were determined. 253 patients with dizziness and 59 healthy individuals completed the DSP-P before visiting the otolaryngologist, and the agreement between the proposed diagnoses of DSP-P and the final diagnosis of the otolaryngologist (our gold standard) was examined.
    Results: The qualitative face validity of DSP-P was confirmed. There was a significant difference between the mean scores of the study groups (p < 0.001). The diagnosis of DSP-P was completely in agreement with the gold standard in 53.3% of cases. Internal consistency was excellent (α≥0.81) for all categories except the persistent postural-perceptual dizziness, superior canal dehiscence and unspecified unsteadiness categories (0.62≤α≤0.69). Generally, the test-retest reliability of the DSP-P scores and diagnoses was very good. The sensitivity of DSP-P was 94.4% for diagnosing benign paroxysmal positional vertigo, 93.5% for Meniere’s disease, 100% for vestibular neuritis, 86.3% for vestibular migraine, and 84.2% for persistent postural-perceptual dizziness.
    Conclusions: The DSP-P was demonstrated to be a valid and reliable history-based diagnostic tool with high sensitivity and specificity.

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    Background and Aim: Persistent postural-perceptual dizziness (PPPD) is a chronic vestibular disorder characterized by persistent dizziness, non-spinning vertigo, or unsteadiness exacerbated by moving visual stimuli and upright postures. Vestibular rehabilitation therapy (VRT) has shown favorable outcomes. While noisy galvanic vestibular stimulation (nGVS) has been associated with improvements in various psychiatric and neurological conditions, its efficacy in PPPD remains unclear. This study aimed to assess the effectiveness of VRT, nGVS, and their combination on patients with PPPD in terms of postural control, dizziness, anxiety, and depression.
    Method: Twenty-seven patients diagnosed with PPPD were randomly assigned to three groups receiving treatment for six weeks: 1) VRT, 2) GVS, and 3) VRT+GVS. Outcome measures included static postural control parameters, Dizziness Handicap Inventory (DHI), and Hospital Anxiety and Depression Scale (HADS) scores.
    Results: All groups demonstrated significant improvements in subjective measures (DHI and HADS) following treatment. Postural control improvements were observed only in specific conditions within each group, with no overall significant differences between the groups except for mediolateral (ML) path length with eyes closed on a soft surface. Significant correlations were observed between improvements in postural control outcomes and questionnaire scores within each group. 
    Conclusion: VRT and GVS, both individually and in combination, were effective in subjective measurements but had minimal impact on static postural control. Adding nGVS to VRT did not provide additional benefits for PPPD patients. The correlations between postural control and psychological outcomes suggest that improvements in perceived dizziness, anxiety, and depression may be linked to postural stabilization.
    Trial Registration Number: The study was registered in the Iranian Registry of Clinical Trials on 18 September 2023 (IRCT20160131026279N6).

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    Background and Aim: To understand the difficulties of elderly in natural listening situations, the present study assessed the ability of participants to extract phonetic information and semantic information in noise. The main objective was to evaluate the relationship between age and performance in Semantic Information Processing (SIP) and Phonetic Information Processing (PIP) tasks.
    Methods: Fifty-three normal hearing participants aged 40 to 65 years were categorized into five age groups. Participants underwent information processing assessments using standardized semantic and phonetic questions from Kannada stories under Signal-to-Noise Ratios (SNR) i.e., quiet, 0 dB SNR, and –4 dB SNR conditions.
    Results: Younger participants outperformed older participants in both SIP and PIP tasks. Performance was optimal in quiet conditions, followed by 0 dB and –4 dB SNR. Except at –4 dB, PIP scores exceeded SIP scores. A significant differences was observed between the groups 1–4 and group 5 at 0 dB SNR in PIP condition only. A moderate negative correlations indicated that performance in both SIP and PIP declined with age, with linear regression revealing reductions of 0.216 and 0.210 each year in SIP and PIP respectively.
    Conclusion: Age-related declines in PIP were noted at one SNR, while SIP remained stable, aligning with the Transmission Deficit Hypothesis (TDH). Nonetheless, regression analyses indicated a general decline in both SIP and PIP with age, supporting the Inhibitory Deficit Hypothesis (IDH).

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    Background and Aim: Effective communication relies on understanding speech in noise, which can be challenging, especially for hearing-impaired children. Auditory attention influences speech perception in noise, and Auditory attention training can help improve this critical auditory skill. Today's neuromodulation methods are used in rehabilitation. Transcranial-direct-current-stimulation(tDCS) is a promising approach among these methods. Our hypothesis is that combining electrical stimulation with behavioral auditory training could accelerate and enhance the effectiveness of auditory training, improving speech comprehension in noise.
    Methods: A pilot study was conducted on 8 children with moderate to severe hearing loss. In this study, tDCS was administered to the right and left dorsolateral prefrontal cortex in addition to behavioral auditory attention training. The participants were divided into two groups, one receiving real stimulation and the other receiving sham stimulation. 20 minutes of intervention were conducted through ten sessions. The test-of-everyday-attention-for-children (TEA-CH) and the monaural-selective-auditory-attention-test (mSAAT) tests were used as behavioral assessments, and the auditory P300 were recorded as an electrophysiological test to measure attention. Also, speech-in-noise tests were utilized. All tests were conducted before, immediately, and one month after training.
    Results: Children in both groups demonstrated noticeable progress in all tests following the training sessions. There was a significant difference in the level of improvement in mSAAT, TEA-CH, word-in-noise, and P300 latency between the two groups. Improvement was more remarkable in children receiving real stimulation.
    Conclusion: When behavioral attention training is combined with attention neuromodulation through tDCS, it may enhance rehabilitation effectiveness and increase the stability of tDCS effects.

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    Background and aim: Speech prosody, the nonlinguistic elements of speech that convey emotions, is crucial for social interactions and speech comprehension. This study aimed to investigate the Validity and reliability of the Speech Prosody Comprehension Test (SPCT) for Persian-speaking children aged 7-10.
    Method: The Persian version of the Speech Prosody Comprehension Test (P-SPCT) was investigated. Face, construct, and discriminant validity, Test-retest reliability, and Internal consistency were examined on 32 children in age 7-10 with 22 (mean age ± SD = 8.63 ± 1.04) normal hearing and 10 (mean age ± SD = 9.20 ± 0.78)with cochlear implant )CI).
    Results: Our result demonstrated good face validity. Construct validity revealed strong correlations in intra-sub score items and between subscales and the total score. A significant difference in mean scores was found between normal hearing and cochlear implant user, supporting discriminant validity (P<0.001). High test-retest reliability was demonstrated, with intraclass correlation coefficients (ICCs) ranging from 0.91 to 0.99 for total and all subscales. The measure demonstrated good internal consistency, with a Cronbach's alpha 0.89 for total score.
    Conclusion: The Persian version of Speech Prosody Comprehension Test was found to be a valid and reliable clinical tool for assessing speech prosody comprehension in children aged 7-10. Further research with larger samples can confirm the generalizability of these findings.

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    Background and Aim: The concept of Musical Competence (MC) encompasses a unique amalgamation of innate aptitude and cultivated skill, encompassing elements of formal training, informal practice, and real-time musical performance. While musical attitude and training influence speech processing abilities and Working Memory (WM), the study examines whether the self-perceived MC plays any role in these processes. This study aimed to investigate whether an individual's self-perceived MC has an impact on their WM, Speech Perception in Noise (SPIN), and Listening Effort (LE) abilities.
    Methods: A non-experimental, standard group comparison research design was employed. Various cognitive tasks, including WM tests, SPIN, and National Aeronautics Space Administration-Task Load Index (NASA-TLX), are administered to gauge different skills within groups.59 musicians were categorized into high self-perceived MC (MChigh) and low self-perceived MC (MClow), as assessed on scores of Edinburgh lifetime musical experience questionnaire, were evaluated for their WM and SPIN abilities.
    Results: Mann Whitney U test was carried out to find group differences, while Fisher Discriminant Analysis (FDA) was performed for group membership prediction. MChigh scored significantly greater scores WM and SPIN scores than MClow, but there were no significant group differences in LE. Cognitive tasks effectively distinguish between groups. Fisher discrimination analysis confirmed the predictive value of tasks like 2n-back and backward-span in group differentiation.
    Conclusion: This study underscores potential cognitive and auditory processing benefits derived from the self-belief of musicians. Musicians with higher MC exhibit enhanced cognitive skills, particularly in WM tasks and auditory processing.

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    Objective:  Recent studies try to clarify the difference of neuro-physiological responses of subject with tinnitus. The eye situation (open/close) is challengeable in electroencephalography researches. QEEG analysis are different on eyes close or open, so the recording of brain activities must be clarified by eyes condition. This study aimed to investigate this further in terms of differences in EEG activity between closed and open eyes condition in resting position of tinnitus patients.

    Method: QEEG was analyzed in forty-six subjects with tinnitus (34 men and 12 women), in two eye conditions (open/close) for 3 minutes at resting position. Relative power of delta, theta, alpha, beta and gamma bands estimated by sLORETA software. Average of 30 electrodes across the scalp was measured for relative power at each rhythm separately and also, Paired T-test analysis for comparison of Delta/Alpha (DAR), Delta+Theta/Alpha+Beta (DTABR) between open/close eyes were done.

    Results: In close eyes condition DAR and DTABR reduced significantly (p=0.009 and p=0.016) in comparison to open eyes. Relative power of delta increased in open eyes whereas surprisingly, alpha reduced significantly in compare to close eyes condition (p<0.001). There was not significant difference between two conditions at theta, beta and gamma rhythms.

    Conclusion: Subjects with tinnitus indicate difference EEG activities at two eyes conditions. These changes, in Alpha band is completely revers in comparison to normal subjects that documents at previous researches. Increase of relative power of Alpha in close eyes and reduce of Delta power may be indicate sever tinnitus based on QEEG data. It seems that is better to select open eyes condition for QEEG analysis. Increase of DAR is a good variable in open eye condition and this study suggest the use of it as a potential biomarker for comparison of the severity of tinnitus.

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    Background and aim: Previous studies have demonstrated that uncompensated Unilateral Vestibular Neuritis (UVN) is a most prevalent cause of dizziness. Despite the many advantages, use of Conventional Vestibular Rehabilitation (CVR) in UVN patients have limitations. The use of tool-based rehabilitation methods can be more pleasant to patients and encourage them to complete the rehabilitation course. This study aimed to compare the effects of combined Whole Body Vibration (WBV), Galvanic Vestibular Stimulation (GVS) and CVR in patients with UVN.
    Methods: UVN patients in the age range of 30 to 50 years were randomly divided into three groups with 17 participants each. first group received of CVR, the second group received CVR+WBV, and the third group received CVR+WBV+GVS, which included four weeks of CVR, twenty 5-minute sessions of WBV and eight 20-minute sessions of GVS. Outcome measurements were postural control parameters, Vestibulo-Ocular Reflex (VOR) gain asymmetry, joint position sense error (JPSE) and Dizziness Handicap Inventory (DHI) scores that were assessed at baseline and after four weeks.
    Results: There was a significant improvement in all measured variables after the CVR, CVR+WBV and CRV+WBV+GVS treatments. Moreover, the CVR+WBV and CRV+WBV+GVS groups showed significantly greater improvement than the CVR group in posturography results, JPSE and DHI score (p < 0.05) except VOR gain asymmetry (p > 0.05).
    Conclusion: CVR, CVR+WBV and CRV+WBV+GVS treatments effectively improve balance function. CVR+WBV and CRV+WBV+GVS training shows additional therapeutic effects in UVN patients. When CVR combined with WBV and GVS, shows additional therapeutic effects in UVN patients.

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    Background and Aim: The AAO-HNS criteria are commonly used to classify Meniere's disease but do not mention the inner ear progression, unlike vestibular staging. This study aimed to compare these methods, filling a gap not explored in previous research.
    Methods: A cross-sectional study recruited patients with MD, aged 18 to 60, from June 8, 2022, to March 20, 2023; however, we excluded patients with problems such as difficulty rolling their eyes, difficulty turning their head, conductive or mixed hearing loss, CNS disorders, retrocochlear lesions, pregnancy, and receiving psychotropic drugs. Furthermore, patients with a history of labyrinthitis, vestibular migraine, stroke, BPPV, or bilateral vestibulopathy within the past 6 months were excluded. All patients were tested with audiometry, VEMPs, caloric test, and vHIT. Two neuro-otologists assessed and classified patients with MD according to the AAO-HNS (1990 and 2020) criteria.
    Results: Forty-two patients were enrolled. The correlation between vestibular staging and both AAO-HNS (1990 and 2020) criteria was medium (p = 0.02 and p < 0.01, respectively). According to AAO-HNS 1995, 69% of definite MD cases were classified as stage C, whereas all probable MD cases and 30% of possible MD cases were categorized as stage B. Regarding AAO-HNS 2020, 70% of definite MD cases were classified as stage C, whereas 33.3% of probable MD cases were classified as stage B.
    Conclusions: A definite MD could predict pathology in the cochleo-sacculo-utricular and lateral canals (stage C), whereas a probable MD could suggest that the lesion involved the cochleo-sacculo-utricular canal (stage B).
    TRIAL REGISTRATION: This trial was registered at Thai Clinical Trials Registry on June 6, 2022 (TCTR20220606003)

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    Background and Aim: Misophonia is a condition characterized by a reduced tolerance to certain sounds or the stimuli linked to those sounds. Our study aims to investigate the auditory brainstem functioning using electrophysiological measures in normal-hearing individuals with and without misophonia.
    Methods: Thirty participants aged between 18 and 30 years were recruited. They were divided into two primary groups: fifteen individuals diagnosed with misophonia and fifteen controls. The selection of participants with misophonia was based on the diagnostic criteria by Schröder et al. and the MisoQuest questionnaire, Auditory brainstem response (ABR) was recorded from all the individuals at lower (11.1/s) and higher stimulus rates (90.1/s).
    Results: On analysing the data, individuals with misophonia showed significantly shorter absolute latencies of ABR waves III and V at 11.1/s. Also, there was no significant difference in the absolute amplitude of ABR waves at 11.1/s and 90.1/s between the individuals with and without misophonia.
    Conclusion: This study indicates that the shorter absolute latencies of ABR waves III and V in individuals in misophonia could be attributed to hyperactivity at the sub-cortical pathway regions compared to the control group.

Case Study

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    Background and Aim: Cochlear implants in post-lingually deaf patients often result in reduced hearing naturality compared to their previous acoustic hearing, making adaptation and speech perception challenging. This study aimed to evaluate participants' perceptual ratings using Speech, Spatial Qualities (SSQ) 12 and the sound quality rating scale, alongside speech and pitch perception, across four different Frequency Allocation Tables (FAT).
    The Cases: Four post-lingual Cochlear Implant (CI) users completed subjective ratings using the Speech, Spatial, and Qualities of Hearing Scale (SSQ 12) and the speech quality rating scale, while objective tests, including speech perception scores in quiet and noise, and psychophysical assessments like pitch perception tasks, were conducted across the four FATs.
    Results: Performance using logarithmic FAT was better across all the domains of SSQ 12 and speech quality rating scale and in Signal to Noise Ratio (SNR) at both 0 and +10 dB. Pitch perception across four FATs reveals a statistically significant difference noted in the apical electrode score when compared with medial and basal electrodes across all the FATs.
    Conclusion: The default FAT provided by the manufacturer may not be suitable for all users due to several factors such as length of the electrode array, shallow insertion of electrodes. Thus, all the FAT options must be utilized and tested for subjective, objective, and psychophysical performance and the best suitable FAT should be set for the specific patient.