Editorial

Background and Aim: The COVID-19 has affected sensory organs in a different manner. This paper aimed to review the auditory-vestibular symptoms associated with COVID-19 and it also investigated the impacts of this pandemic on hearing-impaired community.
Recent Findings: The existing studies related to the effects of COVID-19 on the auditory-vestibular system were reviewed and discussed in order to achieve the overall image of COVID-19 on this system. Moreover, due to the adverse effects of using a mask on the communication function of hearing-impaired people, the effects of the mask on the communication process of hearing-impaired people were also reviewed.
Conclusion: COVID-19 may be accompanying with some auditory and vestibular dysfunctions. Although there are few findings in this area, they showed that the induced hearing loss is often sudden in nature and it is unclear that this situation is because of the ototoxicity of virus treated drugs or not. The vertigo induced by COVID-19 can be a direct invasion of the virus or an invasion by the immune system and its association with hearing loss and tinnitus must be identified, and appropriate referrals should be considered. On the other hand, due to the adverse effects of using personal protective equipment such as masks on the communication performance of hearing-impaired people, the necessary advice and guidance in this field are provided to the medical staff.

Background and Aim: The majority of the world’s population is bilingual. Bilingualism is a form of sensory enrichment that translates to gains in cognitive abilities; these cognitive gains in attention and memory are known to modulate subcortical processing of auditory stimuli. Second language acquisition has a broad impact on various psychological, cognitive, memory, and linguistic processes. Central auditory processing (CAP) is the perceptual processing of auditory information. Due to its importance in bilingu­alism, this study aimed to review the CAP of bilinguals.
Recent Findings: The CAP was studied in three areas: dichotic listening, temporal processing, and speech in noise perception. Regarding dichotic listening, studies have shown that bilinguals have better performance in staggered spondaic word (SSW) test, consonant-vowel dichotic test, dichotic digits test (DDT), and disyllable dichotic test than monolinguals, although similar results have also been reported in SSW and DDT. Regarding temporal processing, the results of bilinguals do not differ from those of monolinguals, although in some cases, it is better in bilinguals. Regarding speech in noise perception, the results between bilinguals and monolinguals are varied depending on the amount of linguistic information available in the stimuli.
Conclusion: Bilingualism has a positive effect on dichotic processing, no effect on temporal processing, and varied effect on speech in noise perception. Bilinguals have poor performance using meaningful speech and better performance using meaningless speech.

Background and Aim: Hearing loss assessment is typically done using the conventional pure tone audiometry (125 Hz to 8000 Hz). Extended high-frequency audiometry (EHFA), which covers the frequency range of 9000 Hz to 20000 Hz, is a very useful tool for detecting early hearing loss before engaging middle and low frequencies. The involvement of these frequencies significantly affects hearing sensitivity. The purpose of the present study was to review the literature on the early diagnosis of hearing impairment using EHFA.
Recent Findings: EHFA has been suggested as a low utilization tool in clinical evaluation. However, in recent years, a great deal of information has been provided in this area. This evaluation has proven to be useful in a variety of areas, including ototoxicity, noise-exposed individuals, and users of personal music devices, hidden hearing loss (HHL), middle ear infections, rheumatoid arthritis, and Sjogren’s syndrome.
Conclusion: Given the importance and application of this clinical tool in the early detection of hearing loss and its use in conjunction with other evaluations, better care planning and prevention can be offered to patients in some areas.

Background and Aim: The central auditory nervous system has the ability to perceptually group similar sounds and segregates different sounds called auditory stream segregation or auditory streaming or auditory scene analysis. Identification of a change in spectral profile when the amplitude of a component of complex tone is changed is referred to as Spectral profile analysis. It serves as an important cue in auditory stream segregation as the spectra of the sound source vary. The aim of the study was to assess auditory stream segregation in individuals with cochlear pathology (CP) and auditory neuropathy spectrum disorder.
Methods: In the present study, three groups of participants were included. Experimental groups included 21 ears in each group with cochlear hearing loss or auditory neuropathy spectrum disorders (ANSD) and control group with 21 ears with normal hearing. Profile analysis was assessed using "mlp" toolbox, which implements a maximum likelihood procedure in MATLAB. It was assessed at four frequencies (250 Hz, 500 Hz, 750 Hz, and 1000 Hz) for all three groups.
Results: The results of the study indicate that the profile analysis threshold (at all four frequencies) was significantly poorer for individuals with CP or ANSD compared to the control group. Although, cochlear pathology group performed better than ANSD group.
Conclusion: This could be because of poor spectral and temporal processing due to loss of outer hair cells at the level of the basilar membrane in cochlear pathology patients and due to the demyelination of auditory neurons in individuals with ANSD.

Background and Aim: Vestibular system has several anatomical connections with cognitive regions of the brain. Vestibular disorders have negative effects on cognitive performance. Hearing-impaired patients, particularly cochlear implant users, have concomitant vestibular disorders. Previous studies have shown that attention assigned to postural control decreases while performing a cognitive task (dual task) in hearing-impaired children. Since the vestibular system and postural control performance develop around 15−16 years of age, the aim of this study was to compare postural control performance during dual task in adolescent boys with normal hearing and cochlear implant (CI) users with congenital hearing-impairment.
Methods: Postural control was assessed in twenty 16−19 year old cochlear implant boys and 40 normal hearing peers with force plate. The main outcomes were displacement in posterior- anterior and medial-lateral planes, and mean speed with and without cognitive task and under on/off-device conditions. Caloric test was performed for CI users in order to examine the peripheral vestibular system.
Results: Ninety-five percent of CI users showed caloric weakness. There were no significant diff­erences in postural control parameters between groups. All performances deteriorated in the foam pad condition compared to the hard surface in all groups. Total mean velocity significantly increased during dual task in normal hearing group and in CI users with off-device.
Conclusion: Although CI users had apparent vestibular disorders, their postural control in both single and dual-task conditions was identical to the normal peers. These effects can be attributed to the vestibular compensation that takes place during growing.

Background and Aim: In recent years, galvanic vestibular stimulation (GVS) has been used as an effective method in rehabilitation and treatment of psychological disorders in children and adults. This study was designed to evaluate the effect of GVS on response inhibition and susta­ined attention in children with attention-deficit/hyperactivity disorder (ADHD).
Methods: Seventeen children with ADHD, within the age range of 9−12 years, participated in this study. All participants were exposed to the go/no-go task. The behavioral outcomes and event-related potentials were recorded at baseline status, in sham condition, and after 20 minutes of exposure to GVS polarities, with an anode on the right mastoid region and a cathode on the left mastoid region.
Results: The results showed that there was a significant difference in reducing the behavioral response of the commission error (p < 0.05). But the reduction in behavioral responses to omission error and reaction time were not significant (p > 0.05). However, regarding ERPs, reduced latencies and increased amplitudes of N2 and P3 waves were observed in GVS intervention, compared to the baseline and sham conditions (p < 0.05).
Conclusion: The present results indicated the potential of GVS in improving of cognition function in children with ADHD and could help us develop a new strategy for rehabilitation of response inhibition disorders in the future.

Background and Aim: Theory of mind (ToM) is very necessary to have successful social interaction. Hearing impairment disrupts the ToM development and language acquisition. This study aimed to compare ToM abilities of children with cochlear implant (CI) and normal hearing (NH) to clarify the role of language skills in ToM development.
Methods: Participants were CI and NH children in two age ranges of 5−6 and 8−9 years. Main measures were basic and advanced tasks of ToM test (Abbreviated as B. ToM and A. ToM), and comprehension of mental–state verbs and relative clauses. Regression analysis was used to assess how language skills predict ToM.
Results: CI children obtained significantly lower scores in all subscales of ToM test (p ≤ 0.001). Regression models for CI group aged 5−6-year showed that their comprehension of mental-state verbs predicted 53% of B. ToM. In CI children aged 8−9 years, comprehension of relative clauses and mental-state verbs together predicted 61% of B. ToM and 73% of A. ToM variances. Furthermore, comprehension of relative clauses predicted 43% of B. ToM and 31% of A. ToM in younger NH children.
Conclusion: Comprehension of mental-state verbs can predict only B. ToM in CI children aged 5−6 years and both B. ToM and A. ToM in CI children aged 8−9 years. Therefore, it is the main factor to predict ToM ability of preschool and school-age children with CI. The role of language should be considered by people who are helping these children for their cognitive problems.

Background and Aim: Tinnitus is a subjective auditory symptom referred to the perception of sound in the absence of external stimuli, and there is no definite treatment for it. Rehabilitation methods and laser therapy have been recommended used for its management. This study aimed to investigate the photobiological effects of low-level laser therapy (LLLT) and tinnitus retraining therapy (TRT) in patients with acoustic trauma-induced tinnitus.
Methods: This clinical trial was conducted on 60 patients suffering from acoustic trauma-induced tinnitus for more than six months, divided into three groups of LLLT, TRT and LLLT + TRT. The Persian version of tinnitus handicap inventory (P-THI), visual analog scale (VAS), and loudness match (LM) scale were used to collect data. The collected data were analyzed in SPSS version.22 software. The effect of time, group and time × group on the scores of VAS, LM, P-THI and its subscales were examined.
Results: There was a statistically significant difference between LLLT + TRT and LLLT groups after intervention in terms of LM (p = 0.002) and VAS (p = 0.001) variables, but no statistical significance for P-THI and its subscales (p = 0.442) was found.
Conclusion: Combination of LLLT and TRT, as a therapeutic protocol, is recommended due to their remarkable effects in reducing acoustic trauma-induced tinnitus symptoms. The use of LLLT method alone, however, is not recommended due to its lower effects.