The effectiveness of the combined transcranial direct current stimulation (tDCS) and tailor-made notched music training (TMNMT) on psychoacoustic, psychometric, and cognitive indices of tinnitus patients.

PURPOSE: Tinnitus network(s) consists of pathways in the auditory cortex, frontal cortex, and the limbic system. The cortical hyperactivity caused by tinnitus may be suppressed by neuromodulation techniques. Due to the lack of definitive treatment for tinnitus and limited usefulness of the individual methods, in this study, a combination of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) and tailor-made notched music training (TMNMT) was used. MATERIAL AND METHODS: In this descriptive-analytic study, 26 patients with chronic unilateral tinnitus of the right ear were randomly divided into the clinical trial group (CTG) and the control group (CG). In both groups, six sessions of tDCS with 2 mA intensity for 20 min, with anode on F4 and cathode on F3, were conducted. Simultaneous with tDCS sessions, and based on TMNMT, the participant was asked to listen passively for 120 min/day, to a CD containing her/his favorite music with a proper notch applied in its spectrum according to the individual's tinnitus The treatment outcome was measured by, psychoacoustic (loudness-matching), psychometric (awareness, loudness and annoyance Visual Analogue Scale (VAS) scores, and Tinnitus Handicap Inventory (THI)) scores, and cognitive assessments (randomized dichotic digits test (RDDT) and dichotic auditory-verbal memory test (DAVMT)). Repeated measurement test was used for statistical analyses. RESULTS: In the CTG, the tinnitus loudness and annoyance VAS scores, and THI were reduced significantly (p = 0.001). In addition, the DAVMT and RDDT scores were enhanced (p = 0.001). Such changes were not observed in the CG (p > 0.05). CONCLUSION: The combination of tDCS and TMNMT led to a reduction in the loudness, awareness, annoyance, and also disability induced by tinnitus in CTG. Furthermore, this method showed an improvement of cognitive functions (auditory divided attention, selective attention and working memory) in the CTG.

Can Galvanic Vestibular Stimulation Be an Effective Management for Bilateral Vestibulopathy?

Background: Vestibulo-ocular and vestibulospinal reflexes contribute to postural stability and gaze stabilization during head and body movements. Thus, chronic disequilibrium, postural imbalance, and oscillopsia occur after bilateral vestibulopathy (BVP). This disorder reduces the daily physical activity and seriously affects the quality of life. Because of its limiting and hazardous consequences, it is necessary to plan an effective therapeutic and rehabilitative strategy for BVP. Recent attempts have used the beneficial effects of stochastic resonance through noisy galvanic vestibular stimulation (nGVS) for this purpose. The present paper aimed to review the effects of nGVS on balance functions in patients with BVP. Methods: This review article investigated research papers in the field of usefulness of nGVS in the treatment of BVP. In the initial search, a total of 134 articles were found with keywords of this manuscript in the SID, Google Scholar, Science Direct, and PubMed databases, of which 7 articles were considered relevant to our subject. Results: The results of these articles suggest that nGVS can have ameliorating effects on the static and dynamic balance as well as on the vestibular performance in BVP patients. Conclusion: In BVP, nGVS may be useful in designing prosthetics for permanent use by the patient, and/or as a method for enhancing the neuroplasticity in combination with other therapies, such as vestibular rehabilitation.

Speech-evoked auditory brainstem response; electrophysiological evidence of upper brainstem facilitative role on sound lateralization in noise.

BACKGROUND AND AIM: Sound lateralization/localization is one of the most important auditory processing abilities, which plays approved role in auditory streaming and speech perception in challenging situations like noisy places. In addition to the main role of lower brainstem centers like superior olivary complex in sound lateralization, efferent auditory system effects on improving auditory skills in everyday auditory challenging positions were revealed. This study evaluated noise effects on lateralization scores in correlation with an objective electrophysiologic test (Speech-ABR in noise), which objectively shows cumulative effects of the afferent and efferent auditory systems at the inferior colliculus and upper brainstem pathway. METHOD: Fourteen normal-hearing subjects in the age range of 18 to 25 participated in this study. Lateralization scores in the quiet and noisy modes were evaluated. Speech-ABR in both ears for quiet mode and three different contralateral noise levels (SNR = + 5, 0, - 5) were recorded, too. Correlation of lateralization scores and Speech-ABR changes in noise was studied. RESULTS: Significant decrease of lateralization scores with latency increase and amplitude decrease of Speech-ABR transient peaks (V, A, O) was seen with noise presentation. A high positive correlation between lateralization decrease with latency increase of onset peaks (V, A) and amplitude decrease of transient peaks (V, A, O) was found in low signal-to-noise ratios. CONCLUSION: The study revealed that in high challenging auditory situations like auditory lateralization in noise, upper brainstem centers and pathways play a facilitative role for main auditory lateralization centers in lower levels.

Auditory brainstem response to speech in children with high functional autism spectrum disorder.

Auditory brainstem response (ABR) provides useful information about the auditory brainstem pathway. However, there is little known about the subcortical speech processing in individuals with autism spectrum disorder (ASD). The aim of the present study was to investigate the subcortical speech processing in children with high functioning ASD. Twenty-eight children with ASD, with a mean age of 14.36 ± 1.86, and 28 typically developing (TD) children, with a mean age of 14.99 ± 1.92, were selected from Rofeydeh Rehabilitation Hospital (Tehran, Iran), and speech ABR (sABR) with a 40 ms synthetic /da/ syllable stimulus was recorded. There was no significant difference between the two groups in terms of age and IQ. Latencies of all waves in sABR and duration of V-A complex were significantly longer in children with ASD than in TD children. It was concluded that patients with ASD have deficits in the temporal neural encoding of speech at the brainstem level. Further studies are needed to generalize this result.

Correlation between Auditory Spectral Resolution and Speech Perception in Children with Cochlear Implants.

BACKGROUND: Variability in speech performance is a major concern for children with cochlear implants (CIs). Spectral resolution is an important acoustic component in speech perception. Considerable variability and limitations of spectral resolution in children with CIs may lead to individual differences in speech performance. The aim of this study was to assess the correlation between auditory spectral resolution and speech perception in pediatric CI users. METHODS: This cross-sectional study was conducted in Shiraz, Iran, in 2017. The frequency discrimination threshold (FDT) and the spectral-temporal modulated ripple discrimination threshold (SMRT) were measured for 75 pre-lingual hearing-impaired children with CIs (age=8-12 y). Word recognition and sentence perception tests were completed to assess speech perception. The Pearson correlation analysis and multiple linear regression analysis were used to determine the correlation between the variables and to determine the predictive variables of speech perception, respectively. RESULTS: There was a significant correlation between the SMRT and word recognition (r=0.573 and P<0.001). The FDT was significantly correlated with word recognition (r=0.487 and P<0.001). Sentence perception had a significant correlation with the SMRT and the FDT. There was a significant correlation between chronological age and age at implantation with SMRT but not the FDT. CONCLUSION: Auditory spectral resolution correlated well with speech perception among our children with CIs. Spectral resolution ability accounted for approximately 40% of the variance in speech perception among the children with CIs.

Rotational and Collic Vestibular-Evoked Myogenic Potential Testing in Normal Developing Children and Children With Combined Attention Deficit/Hyperactivity Disorder.

OBJECTIVES: Vestibular dysfunction in childhood can have a major effect on a child's developmental process. Balance function has been reported to be poorer in children with attention deficit and hyperactivity disorder (ADHD) than in their typically developing peers. Due to contradictory available evidence and the paucity of research on vestibular function specifically in children with combined ADHD (cADHD), we designed this aged-matched study to assess vestibular function in children with cADHD. DESIGN: We enrolled 30 typically developing children (15 boys and 15 girls; mean age, 9 years 6 months; range, 7 to 12 years) and 33 children (19 boys and 14 girls; mean age, 9 years 0 months; range, 7 to 12 years) with cADHD diagnosed by our research psychiatrist. Typically developing controls were used to obtain normative data on vestibular testing and to examine the impact of age on the vestibular response parameters, and these results were compared with those of the cADHD group. All children underwent the sinusoidal harmonic acceleration subtype of the rotary chair test (0.01, 0.02, 0.08, 0.16, and 0.32 Hz) and the cervical vestibular-evoked myogenic potential (cVEMP) test. RESULTS: At all five frequencies in the sinusoidal harmonic acceleration test, there was no significant correlation between age and any of the following rotary chair response parameters in typically developing children: vestibulo-ocular reflex (VOR) gain, phase, asymmetry, and fixation index. Furthermore, there was no significant correlation between age and any of the following cVEMP parameters for the right and left ears of control group: p1 and n1 latency, amplitude, threshold, and amplitude ratio. Significantly higher VOR gains were observed for children with cADHD at frequencies of 0.01 (p = 0.001), 0.08 (p < 0.001), 0.16 (p = 0.001), and 0.32 (p = 0.003) Hz, when compared with the control group. Furthermore, fixation abilities were significantly lower in the cADHD group than in the control group at 0.16 (p < 0.001) and 0.32 (p < 0.001) Hz. cVEMP parameters showed no significant differences between the two groups. CONCLUSIONS: Our results showed higher VOR gains and poorer fixation abilities in children with cADHD compared with typically developing children. Cerebellar dysfunction in patients with ADHD has been well documented in the literature, and our findings of cVEMP and rotary chair tests for these children showed impaired vestibular function in these children, based on increased VOR gain values and decreased fixation capabilities. Because VOR gain is mediated through the inferior olive and controlled by the cerebellum, our results suggest that central inhibition of vestibular function may be deficient in children with cADHD, resulting in higher VOR gains. Also, there is general agreement that failure of fixation suppression indicates a central lesion. The lesion can originate from the parietal-occipital cortex, the pons, or the cerebellum. However, failure of fixation suppression is most prominent in lesions involving the midline cerebellum that could be counted for children with cADHD. We believe that this contribution is theoretically and practically relevant as high VOR gains and decreased suppression capabilities may result in symptoms of reading and writing difficulties, learning disabilities, vertigo, and motion sickness in these children. Therefore, assessment of vestibular function in children with cADHD at a young age must be considered when developing rehabilitation protocols for these children.

Reliability of Interaural Time Difference-Based Localization Training in Elderly Individuals with Speech-in-Noise Perception Disorder.

BACKGROUND: Previous studies have shown that interaural-time-difference (ITD) training can improve localization ability. Surprisingly little is, however, known about localization training vis-à-vis speech perception in noise based on interaural time difference in the envelope (ITD ENV). We sought to investigate the reliability of an ITD ENV-based training program in speech-in-noise perception among elderly individuals with normal hearing and speech-in-noise disorder. METHODS: The present interventional study was performed during 2016. Sixteen elderly men between 55 and 65 years of age with the clinical diagnosis of normal hearing up to 2000 Hz and speech-in-noise perception disorder participated in this study. The training localization program was based on changes in ITD ENV. In order to evaluate the reliability of the training program, we performed speech-in-noise tests before the training program, immediately afterward, and then at 2 months' follow-up. The reliability of the training program was analyzed using the Friedman test and the SPSS software. RESULTS: Significant statistical differences were shown in the mean scores of speech-in-noise perception between the 3 time points (P=0.001). The results also indicated no difference in the mean scores of speech-in-noise perception between the 2 time points of immediately after the training program and 2 months' follow-up (P=0.212). CONCLUSION: The present study showed the reliability of an ITD ENV-based localization training in elderly individuals with speech-in-noise perception disorder.

Envelope-based inter-aural time difference localization training to improve speech-in-noise perception in the elderly.

Background: Many elderly individuals complain of difficulty in understanding speech in noise despite having normal hearing thresholds. According to previous studies, auditory training leads to improvement in speech-in-noise perception, but these studies did not consider the etiology, so their results cannot be generalized. The present study aimed at investigating the effectiveness of envelopebased interaural time difference (ITD ENV) localization training on improving ITD threshold and speech-in-noise perception. Methods: Thirty-two elderly males aged 55 to 65 years with clinically diagnosed normal hearing at 250-2000 Hertz, who suffered from speech-in-noise perception difficulty participated in this study. These individuals were randomly divided into training and control groups: 16 elderlies in the experimental group received envelope-based interaural time difference localization training in 9 sessions, but 16 matched elderlies in the control group did not receive any training. The ITD ENV threshold and spatial word recognition score (WRS) in noise were analyzed before and after the localization training. Results: Findings demonstrated that following the training program, the interaural time difference envelope threshold and spatial word recognition score (WRS) in noise were improved significantly in the experimental group (p≤ 0.001). Moreover, a significant difference was detected in interaural time difference envelope threshold and spatial word recognition score (WRS) in noise (p≤ 0.001) before and after the training in the experimental group. Conclusion: The results of the present study revealed the effectiveness of envelope- based interaural time difference localization training in localization ability and speech in noise perception in the elderlies with normal hearing up to 2000 Hz who suffered from speech-in-noise perception difficulty.

Relation between Working Memory Capacity and Auditory Stream Segregation in Children with Auditory Processing Disorder.

BACKGROUND: This study assessed the relationship between working memory capacity and auditory stream segregation by using the concurrent minimum audible angle in children with a diagnosed auditory processing disorder (APD). METHODS: The participants in this cross-sectional, comparative study were 20 typically developing children and 15 children with a diagnosed APD (age, 9-11 years) according to the subtests of multiple-processing auditory assessment. Auditory stream segregation was investigated using the concurrent minimum audible angle. Working memory capacity was evaluated using the non-word repetition and forward and backward digit span tasks. Nonparametric statistics were utilized to compare the between-group differences. The Pearson correlation was employed to measure the degree of association between working memory capacity and the localization tests between the 2 groups. RESULTS: The group with APD had significantly lower scores than did the typically developing subjects in auditory stream segregation and working memory capacity. There were significant negative correlations between working memory capacity and the concurrent minimum audible angle in the most frontal reference location (0° azimuth) and lower negative correlations in the most lateral reference location (60° azimuth) in the children with APD. CONCLUSION: The study revealed a relationship between working memory capacity and auditory stream segregation in children with APD. The research suggests that lower working memory capacity in children with APD may be the possible cause of the inability to segregate and group incoming information.

Effects of vowel auditory training on concurrent speech segregation in hearing impaired children.

OBJECTIVE: This clinical trial investigated the ability of concurrent speech segregation in hearing impaired children. The auditory behavioral responses and auditory late responses (ALRs) were compared between test and control groups prior to vowel auditory training and after 3 and 6 months of vowel auditory training to find the effects of bottom-up training on concurrent speech segregation in hearing impaired children. METHODS: Auditory behavioral responses for 5 vowels and ALRs for double synthetic vowels, with special physical properties, were recorded in a timetable in 30 hearing impaired children (test group = 15 and control group = 15). RESULTS: Identification score and reaction time data showed that the test group was approximately proficient for some vowels (P < .05 for vowels /æ/, /e/, and /u:/) and took less time to process after 6 months of training. N1-P2 amplitude indexing of the vowel change detection and reflecting central auditory speech representation without active client participation has been increased in the test group (P < .05). CONCLUSION: The present study showed training-related improvements in concurrent speech segregation. This information provided evidence for bottom-up training based on F0, its differences in auditory scene analysis, and neural underpinnings.

Comparison of the effects of N-acetyl-cysteine and ginseng in prevention of noise induced hearing loss in male textile workers.

Previous studies revealed the role of antioxidant agents in prevention of noise induced hearing loss (NIHL). The aim of this study was to compare the protective effect of N-acetyl-cysteine (NAC) and ginseng on protection of NIHL in textile workers exposed to continuous noise in daily working. In this study, 48 participants were randomly allocated to three groups; Group I received NAC 1200 mg/day, Group II received ginseng 200 mg/day, and Group III (control group) received no supplement. Pure tone audiometry and high frequency audiometry were performed preshift before and after 14 days (on day 15). Linear regression analysis results showed reduced noise-induced temporary threshold shift (TTS) for NAC and ginseng groups at 4, 6 and 16 kHz (P < 0.001) in both ears. Furthermore, the protective effects were more prominent in NAC than ginseng. Our results show that NAC and ginseng can reduce noise induced TTS in workers exposed to occupational noise. Further studies are needed to prove antioxidants benefits in hearing conservation programs.

Concurrent auditory perception difficulties in older adults with right hemisphere cerebrovascular accident.

BACKGROUND: Older adults with cerebrovascular accident (CVA) show evidence of auditory and speech perception problems. In present study, it was examined whether these problems are due to impairments of concurrent auditory segregation procedure which is the basic level of auditory scene analysis and auditory organization in auditory scenes with competing sounds. METHODS: Concurrent auditory segregation using competing sentence test (CST) and dichotic digits test (DDT) was assessed and compared in 30 male older adults (15 normal and 15 cases with right hemisphere CVA) in the same age groups (60-75 years old). For the CST, participants were presented with target message in one ear and competing message in the other one. The task was to listen to target sentence and repeat back without attention to competing sentence. For the DDT, auditory stimuli were monosyllabic digits presented dichotically and the task was to repeat those. RESULTS: Comparing mean score of CST and DDT between CVA patients with right hemisphere impairment and normal participants showed statistically significant difference (p=0.001 for CST and p<0.0001 for DDT). CONCLUSION: The present study revealed that abnormal CST and DDT scores of participants with right hemisphere CVA could be related to concurrent segregation difficulties. These findings suggest that low level segregation mechanisms and/or high level attention mechanisms might contribute to the problems.

Combined Bifrontal Transcranial Direct Current Stimulation and Auditory Stroop Training in Chronic Tinnitus.

Patients with tinnitus experience difficulties in cognitive control and executive functions. Many of which are regarded as the cause of tinnitus rather than its complications. Methods for the improvement of inhibitory and cognitive control seem to be effective in the control of tinnitus. In this study, transcranial direct current stimulation and auditory Stroop exercise were have been to improve inhibitory control and the ability to ignore tinnitus in patients suffering from chronic tinnitus. 34 patients with chronic tinnitus (> 6 months) were randomly divided into two groups. The first group consist of 17 patients who received 6 sessions of tDCS followed by 6 sessions of auditory Stroop training. The second group received 6 sessions of sham tDCS followed by 6 sessions of auditory Stroop training. The initial evaluations including pure tone audiometry, psychoacoustic measurements, tinnitus handicap inventory (THI) survey and visual analog scale (VAS) of annoyance and loudness were performed before, immediately after, and one month after the tDCS, sham, and Stroop training. The results of this study revealed a significant reduction in THI score, VAS of loudness, and annoyance of tinnitus. A significant correlation was detected between the reaction time of incongruent words in the Stroop task and improvement of THI score and VAS of annoyance. Combined tDCS and Stroop training efficiently improve chronic tinnitus.

Effect of Cognitive Rehabilitation by Auditory Stroop Training on Quality of Life of Individuals with Tinnitus.

Background: Studies have shown that tinnitus patients have difficulties in cognitive function such as memory and attention. The Stroop task engages the attention network where one aspect of the stimulus is noticed while the other one is ignored. Thus, Stroop training can improve the patient's cognitive control and ability to ignore the tinnitus signal. Method: Thirty chronic tinnitus (> 6 months) patients were included in this study. They were distributed into two 15-member groups: intervention and control. Common audiometric, psychometric, and psychoacoustic evaluations of tinnitus were performed for two groups before intervention and after auditory Stroop training of group 1. Results: There was significant difference in the quality of life and THI scores, VAS of annoyance, and reaction time of Stroop task before and after intervention in group1. The decreased reaction time was positively correlated with improved quality of life, THI score, and VAS of annoyance. Conclusion: Cognitive rehabilitation using tasks such as auditory Stroop can be effective in controlling tinnitus by improving cognitive control. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-04011-w.

Effect of an Auditory Temporal Training Program on Speech Fluency of Children with Developmental Stuttering.

Objectives: The present study aims to investigate the effect of a temporal processing-based auditory training program on alleviating stuttering severity in children diagnosed with auditory temporal processing disorders. Materials & Methods: Thirty-one children with stuttering diagnosed with auditory temporal processing disorders participated in this study (intervention group: 17 participants between seven to 12 years old; control group: 14 participants between eight to 12 years old). The auditory temporal processing test and Stuttering Severity Instrument-3 (SSI-3) were examined before/after 12 sessions (nearly 540 minutes) of training and three months following the conclusion of the intervention. Results: According to the results, auditory temporal processing improved significantly in the intervention group after temporal processing-based auditory training. Besides, the differences between the intervention and control groups were significant (P<0.05). The improvement of auditory temporal processing skills remained stable in the post-training evaluation after three months (P>0.05). Although the SSI-3 score was somewhat improved in the intervention group, no significant difference was found between the two groups (P=0.984). Conclusion: The findings revealed that auditory temporal processing training acted as a complementary therapy alleviating the stuttering severity of children who stutter with auditory temporal processing disorders to some extent.

Testing A Hypothesis: Tinnitus Control by Enhancing Physiological Inhibition.

Background: Deficit in cognitive functions and central executive function is one of the popular hypotheses on the underlying cause of tinnitus. Some studies expressed the effect of tinnitus on the inhibitory cognitive tasks, referring to the slower inhibitory results such as in the Stroop task in the people suffering from tinnitus as compared to normal subjects. Since Stroop engages the network overlapping the attention and tinnitus distress networks, it seems likely that Stroop exercises can effectively contribute to controlling the tinnitus and its consequent distress through improvement of the cognitive function and increasing the physiological inhibition. Method: A total of 25 patients with chronic tinnitus (> 6 months) were randomly divided into two groups: an intervention group of 15 patients and a control group of 10 patients. Both groups were subjected to initial evaluations including pure tone audiometry, psychoacoustic measurements, tinnitus handicap inventory (THI) survey, and visual analogue scale (VAS) of annoyance and loudness. The intervention group underwent a rehabilitation program consisting of 6 Stroop training sessions. The control group didn't receive any training. Afterwards, both groups were reevaluated and the results were compared to those of initial evaluations. Results: Results of this study indicated significant differences in THI scores and VAS of annoyance, before and after Stroop training in the intervention group, although no significant difference was observed when it came to VAS of loudness. Conclusion: Successive sessions of conflict processing training can improve the annoyance of tinnitus by enhancing the patient's inhibition control, making this task a safe practice for tinnitus treatment.

Effect of tinnitus distress on auditory steady-state response amplitudes in chronic tinnitus sufferers.

Tinnitus is a bothersome disorder of primarily unknown etiology that affects a large number of people worldwide. Tinnitus distress is the most common clinical complaint by tinnitus sufferers because it strongly affects their personal and social life. Many studies have been carried out to determine the relation between tinnitus pathophysiology and electrophysiological findings such as the auditory steady-state response (ASSR). The results of such studies have been contradictory. The current study aimed to detect a possible relation between tinnitus distress and ASSR amplitudes. The tinnitus participants were divided into high and low distress subgroups according to their tinnitus handicap inventory (THI) scores. The ASSR stimuli were carrier frequencies with low (500 Hz), mid (2000 Hz), and high (4000 Hz) amplitude-modulated tones. ASSR amplitudes were calculated in anterio-frontal (F3, Fz, F4), centro-frontal (FC3, FCz, FC4), left auditory (T3, C5, C3) and right auditory (C4, T4, C6) regions of interest (ROI). Twenty-four right-handed subjects with non-pulsatile chronic tinnitus and 23 normal matched participants participated in this study. For recording ASSR amplitudes were used from 32-electrode EEG recording. Two-way repeated-measurement ANOVA was used to compare the ASSR amplitudes. The findings showed that the ASSR amplitudes in the tinnitus group with low distress were higher (better) than in the group with high distress (p < 0.001). This finding was seen in anterio-frontal and right auditory regions and at all carrier frequencies. The results indicated that there is a relation between the ASSR amplitude and the degree of tinnitus distress as measured by the THI questionnaire.

Long latency auditory evoked potentials and object-related negativity based on harmonicity in hearing-impaired children.

Hearing-impaired children (HIC) have difficulty understanding speech in noise, which may be due to difficulty parsing concurrent sound object based on harmonicity cues. Using long latency auditory evoked potentials (LLAEPs) and object-related negativity (ORN), a neural metric of concurrent sound segregation, this study investigated the sensitivity of HIC in processing harmonic relation. The participants were 14 normal-hearing children (NHC) with an average age of 7.82 ± 1.31 years and 17 HIC with an average age of 7.98 ± 1.25 years. They were presented with a sequence of 200 Hz harmonic complex tones that had either all harmonic in tune or the third harmonic mistuned by 2%, 4%, 8%, and 16% of its original value while neuroelectric brain activity was recorded. The analysis of scalp-recorded LLAEPs revealed lower N2 amplitudes elicited by the tuned stimuli in HIC than control. The ORN, isolated in difference wave between LLAEP elicited by tuned and mistuned stimuli, was delayed and smaller in HIC than NHC. This study showed that deficits in processing harmonic relation in HIC, which may contribute to their difficulty in understanding speech in noise. As a result, top-down and bottom-up rehabilitations aiming to improve processing of basic acoustic characteristics, including harmonics are recommended for children with hearing loss.

Effects of auditory processing training on speech perception and brainstem plastisity in adolescents with autism spectrum disorders.

OBJECTIVE: Autism spectrum disorder (ASD) is a neurodevelopmental disorder. A major problem of ASD is speech perception impairment in the presence of background noise. Additionally, researchers have reported temporal auditory processing impairment in patients with ASD. In the present study, we evaluated the effects of a temporal-based training program on improvement of speech perception in the presence of noise using the speech auditory brainstem response (sABR). MATERIALS & METHODS: Twenty-eight adolescents with high functional ASD with the mean age of 14.35±1.86 years were randomly selected and divided into an ASD group (11 males and three females) and a control group (13 males and one female). All the subjects had a normal hearing and intelligence threshold and had no history of neurological disorder.A speech perception test was performed in signal-to-noise ratios of 0 and +10. The intervention group received a temporal processingbased auditory training program, and the control group received a conventional training program. A P-value of <0.05 was considered significant. RESULTS: After training, speech perception in the presence of noise was significantly higher (P <0.001) and the latency of all sABR waves was lower in the intervention group compared to the control group. CONCLUSION: Improvement of speech perception in noisy environments and the reduced latency of sABR waves following a temporal processingbased training program highlight the role of brainstem neural plasticity in speech processing.

Comparison of efficacy of vestibular rehabilitation and noisy galvanic vestibular stimulation to improve dizziness and balance in patients with multiple sclerosis.

BACKGROUND: Dizziness and imbalance are common symptoms in patients with multiple sclerosis (PwMS), and rehabilitation interventions varying greatly in effectiveness. OBJECTIVE: To compare the effectiveness of vestibular rehabilitation therapy (VRT) and noisy galvanic vestibular stimulation (nGVS) on dizziness and balance in PwMS. METHODS: This was a single-blind, randomized controlled trial. Twenty-four PwMS were randomly divided into groups of VRT, nGVS, and Control. The VRT and the nGVS groups underwent the intervention program. The patients were assessed with the composite score in anteroposterior and lateral directions (CS AP and LAT) obtained by sensory organization test (SOT), Dizziness Handicap Inventory (DHI), and Activities-Specific Balance Confidence Scale (ABC). RESULTS: The VRT group showed greater improvements in CS AP and LAT, DHI total score, and ABC total score compared with the nGVS group and the control group. No significant difference was found between the nGVS group and the control group. These results were approximately stable at the 4-week follow-up. CONCLUSIONS: These findings provided evidence for effectiveness of the VRT in improvement of dizziness and balance in PwMS. These improvements were not associated with the nGVS. Further studies are needed to assess the effectiveness of the nGVS on dizziness and balance in PwMS.