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.

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.

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.

Auditory temporal processing assessment in children with developmental stuttering.

OBJECTIVE: Stuttering is a developmental disorder of speech production with a dynamic and multifactorial nature. Scientific theories mentioned the role of auditory processing disorder in stuttering. Investigating the auditory processing in stuttering would provide insights into the mechanisms of stuttering. The details of basic auditory processing in children with stuttering (CWS) continue to remain uncertain. This study aimed to investigate the auditory temporal processing (ATP) in CWS and also its relationship with the stuttering severity. METHODS: The participants of this comparative cross-sectional study were 54 CWS and 63 children without stuttering (CWOS). All children were between 7 and 12 years old. ATP ability of the participants was measured using the Backward Masking (BM), Duration Pattern (DP), and Gap in Noise (GIN) tests. Then, the groups were compared in terms of ATP results. The correlation between the scores of these tests and stuttering severity was assessed. RESULTS: According to the results, CWS showed poorer performance on DP, BM and GIN tests when compared with CWOS. Moreover, the stuttering severity had a significant negative correlation with the DP scores and percentage of correct identification scores in GIN; whereas it had a significant positive correlation with the BM thresholds. CONCLUSIONS: The results showed that some CWS have ATP disorder, which could exacerbate their stuttering. These findings highlighted the role of ATP disorder in stuttering.

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.

Speech-ABR in contralateral noise: A potential tool to evaluate rostral part of the auditory efferent system.

In parallel with the auditory afferent system, the auditory efferent system is active in all parts of the auditory pathways from auditory cortex to the cochlea. The auditory efferent system has two main segments: the rostral and the caudal parts. The rostral part, which starts from the cortical centers to thalamic nuclei and continues into collicular pathways in rostral brainstem, which sends its neural fibers to the main collicular nuclei especially inferior colliculus. The caudal part includes the olivocochlear bundle, which originates from the superior olivary complex and terminates on the cochlear hair cells. Most studies about the auditory efferent system have focused only on the caudal part using otoacoustic emission suppression test. Speech-evoked auditory brainstem response (S-ABR) as an electrophysiologic test that uses speech stimuli to simulate real-life auditory conditions, reflects the performance of rostral brainstem centers, so structurally seems to be an appropriate candidate to examine the rostral part of the auditory efferent system. Our hypothesis is that S-ABR in noisy condition, a typical condition for stimulating the auditory efferent system, has the potential to be used as an objective noninvasive electrophysiologic test for studying the rostral auditory efferent system in diagnosis and treatment/rehabilitation follow-ups. In addition, S-ABR can potentially reflect higher-order auditory functions and the effects of their dysfunctions on the lower brainstem. This characteristic makes S-ABR even more suitable tool for evaluation of the efferent system. To evaluate our hypothesis, Eighteen normal hearing subjects in the age range of 18-25 were tested in a pilot study for S-ABR in quiet mode and three signal to noise ratios of +10,0 and -10 for both ears. Then we checked the correlation between the results of S-ABR in different conditions and scores of auditory behavioral tests that auditory efferent system is involved in them: Consonant-Vowel perception in noise, dichotic Consonant-Vowel-Consonant and sound lateralization in noise. The results of our pilot study showed a significant correlation between S-ABR changes in noise with the scores of the behavioral tests in noisy or dichotic situations. Findings of the current study suggest that S-ABR with specific contralateral noise can be an appropriate option for evaluating the performance of rostral part of the auditory efferent system and may be suitable for top-down auditory training follow-ups, although the generalization of these results needs further studies in different groups with different auditory processing abnormalities or skills.

Binaural Interaction Component of Middle Latency Response in Children Suspected to Central Auditory Processing Disorder.

Binaural processing disorder is an important deficit in children with (C)APD so binaural processing evaluations are crucial. There are subjective and objective tests for assessing binaural processing. Subjective tests require patient attention and active so objective evaluation of binaural processing is important. The aim of present study was investigating binaural interaction component (BIC) of middle latency response (MLR) in children suspected to (C)APD. Sixty 8-12 year-old children suspected to (C)APD and sixty normal children were selected based on inclusion criteria. Both groups were matched in terms of sex (40 boys and 20 girls) and age (9.05 ± 1.25 years old). MLR test (monaural right ear, monaural left ear and binaural) was performed in all the cases and BIC was calculated by subtracting binaural response from summed monaural responses. Independent t test showed that latency of Pa and Na (ms), Pa-Na amplitude (µv), BIC latency (ms) and amplitude (µv) were significantly different from normal subjects (p value ≤0.001). Present study showed that MLR and BIC of MLR are clinically available and objective tests that can be used to determining children suspected to (C)APD. These tests might have the potential to separating normal children from children with (C)APD objectively.

Auditory Lateralization Training Effects on Binaural Interaction Component of Middle Latency Response in Children Suspected to Central Auditory Processing Disorder.

Many children with central auditory processing disorder (C)APD suffer from spatial processing disorder and benefit from binaural processing training including auditory lateralization training. There are subjective tests for evaluating auditory training effects in children with (C)APD but they rely on patient's attention and cooperation so there is a need for appropriate objective tests. The aim of present study was investigating effects of auditory lateralization training on binaural interaction component (BIC) of middle latency response (MLR). This study was an analytical interventional study. Sixty children suspected to (C)APD (40 boys and 20 girls) were selected based on inclusion criteria and were divided into two groups: control and training group. Auditory lateralization training included 12 formal sessions under headphone by using interaural time difference and performed as a game. MLR (monaural right ear, monaural left ear and binaural) and monaural selective auditory attention test (mSAAT) tests were performed in all the cases. BIC was calculated by subtracting binaural response from summed monaural responses. Covariance test showed that BIC latency decreased and BIC amplitude increased significantly and mSAAT score increased significantly in training group after auditory lateralization training (p value ≤ 0.001). In present study BIC of MLR had potential to show underlying neurophysiologic changes after auditory lateralization training in children suspected to (C)APD objectively. It is in agreement with behavioral improvements after training (mSAAT improvements).

Binaural sensitivity to temporal fine structure and lateralization ability in children with suspected (central) auditory processing disorder.

OBJECTIVE: Previous studies have shown that a subgroup of children with suspected (central) auditory processing disorder (SusCAPD) have insufficient ability to use binaural cues to benefit from spatial processing. Thus, they experience considerable listening difficulties in challenging auditory environments, such as classrooms. Some researchers have also indicated the probable role of binaural temporal fine structure (TFS) in the perceptual segregation of target signal from noise and hence in speech perception in noise. Therefore, in the present study, in order to further investigate the underlying reason for listening problems against background noise in this group of children, their performance was measured using binaural TFS sensitivity test (TFS-LF) as well as behavioral auditory lateralization in noise test, both of which are based on binaural temporal cues processing. METHODS: Participants in this analytical study included 91 children with normal hearing and no listening problems and 41 children (9-12 years old) with SusCAPD who found it challenging to understand speech in noise. Initially, the ability to use binaural TFS was measured at three frequencies (250, 500 and 750Hz) in both the groups, and the results of preliminary evaluations were compared between normal children and those with SusCAPD who participated in the study. Thereafter, the binaural performance of the 16 children with SusCAPD who had higher thresholds than the normal group at all three frequencies tested in TFS-LF test was examined using the lateralization test in 7 spatial locations. RESULTS: Total 16 of the 41 children with SusCAPD who participated in this study (39%) showed poor performance on the TFS-LF test at all three frequencies, compared to both normal children and other children in the APD group (p<0.05). Furthermore, children in the APD group with binaural TFS coding deficits at all three frequencies revealed significant differences in the lateralization test results compared to normal children (p<0.05). CONCLUSION: Findings of the current study demonstrated that one of the underlying causes for the difficulty understanding speech in noisy environments experienced by a subgroup of children with SusCAPD can be the reduced ability to benefit from binaural TFS information. This study also showed that a reduced ability to use binaural TFS cues in the group of children with SusCAPD was accompanied by reduced binaural processing abilities in the lateralization test which also admit the presence of binaural temporal processing deficits in this group of children.

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.

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.

The effect of serum vitamin D normalization in preventing recurrences of benign paroxysmal positional vertigo: A case-control study.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is a condition with recurrent attacks in a significant proportion of patients. The present case- control study was conducted to assess the influence of serum vitamin D normalization on recurrent attacks of vitamin D deficient patients. METHODS: Diagnosis of BPPV was made based on history and clinical examination and exclusion of other conditions. Serum 25-hydroxy vitamin D (25-OHD) was measured using ELISA method and a levels of < 20 ng/ml was considered a deficiency of vitamin D. Inclusion criteria were as follows: history of recurrent attacks and serum 25-OHD<20.ng/ml. While the patients with history of trauma, surgery and chronic systemic diseases were excluded. The patients were classified into two groups: treatment and control, intermittently. Both groups received Epley rehabilitation therapy one session per week for 4 weeks but the treatment group received an additional supplement of 50.000 IU of vitamin D (cholecalciferol) weekly for two months to achieve serum 25-OHD ≥ 30 ng/ml and the study patients were followed-up for 6 months. RESULTS: Twenty-seven patients were allocated to each group. At baseline, serum 25-OHD was similar (10.7±2.3 vs 11.41±1.9, P=0.23). At month 2, serum 25-OHD in the treatment group increased significantly to ≥ 30 ng/ ml, whereas serum 25-OHD in the control group remained unchanged (34.2±3.3 vs 10.6 10.6±2.2 ng/ml, P=0.001). During the follow-up period, attacks of BPPV in the treatment group decreased significantly compared with the control group (14.8% vs 96.3% OR= 0.18, P=0.001). CONCLUSION: The findings of this study indicate that the normalization of serum vitamin D significantly reduces BPPV recurrences.

Data on galvanic-evoked head movements in healthy and unilaterally labyrinthectomized rats.

In this dataset, we analyzed galvanic-evoked head movements (GEHMs) in the spatial planes of yaw, and roll in normal and unilaterally labyrinthectomized (UL) Wistar rats. The rats were assigned in 4 groups of 10: control, sham, right-UL and left-UL. Bilateral galvanic vestibular stimulation (GVS) was presented by our "ring-shaped electrode" design (see "Short-term galvanic vestibular stimulation promotes functional recovery and neurogenesis in unilaterally labyrinthectomized rats" (M. Shaabani et al., 2016) [1]). Required data were collected through video recording of GEHMs followed by image processing and statistical analysis.

Effects of an Auditory Lateralization Training in Children Suspected to Central Auditory Processing Disorder.

BACKGROUND AND OBJECTIVES: Central auditory processing disorder [(C)APD] refers to a deficit in auditory stimuli processing in nervous system that is not due to higher-order language or cognitive factors. One of the problems in children with (C)APD is spatial difficulties which have been overlooked despite their significance. Localization is an auditory ability to detect sound sources in space and can help to differentiate between the desired speech from other simultaneous sound sources. Aim of this research was investigating effects of an auditory lateralization training on speech perception in presence of noise/competing signals in children suspected to (C)APD. SUBJECTS AND METHODS: In this analytical interventional study, 60 children suspected to (C)APD were selected based on multiple auditory processing assessment subtests. They were randomly divided into two groups: control (mean age 9.07) and training groups (mean age 9.00). Training program consisted of detection and pointing to sound sources delivered with interaural time differences under headphones for 12 formal sessions (6 weeks). Spatial word recognition score (WRS) and monaural selective auditory attention test (mSAAT) were used to follow the auditory lateralization training effects. RESULTS: This study showed that in the training group, mSAAT score and spatial WRS in noise (p value≤0.001) improved significantly after the auditory lateralization training. CONCLUSIONS: We used auditory lateralization training for 6 weeks and showed that auditory lateralization can improve speech understanding in noise significantly. The generalization of this results needs further researches.

Influence of supplemental vitamin D on intensity of benign paroxysmal positional vertigo: A longitudinal clinical study.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is linked to vitamin D deficiency. This clinical trial aimed to determine the influence of vitamin D supplementation on intensity of BPPV. METHODS: The study population was selected consecutively and the diagnosis of BPPV was made by history and clinical examination and exclusion of other conditions. Intensity of BPVV was assessed based on VAS score (0-10). Serum 25-hydroxyvitamin D (25-OHD) was measured using ELISA method and levels < 20 ng/ml was considered a deficiency. All patients received rehabilitation treatment using Epley's maneuver one time per week for one month. Serum 25-OHD deficient patients were classified as treated and non-treated groups (rehabilitation with or without 50.000 IU cholecalciferol weekly for two months).The results of treatment were compared with vitamin D sufficient group as control. All patients were followed-up for 6 months. RESULTS: After two months of treatment, in both vitamin D treated and non-treated groups the intensity of BPPV decreased significantly as compared with control (P=0.001 for both groups) but at endpoint, the intensity of BPPV aggravated and regressed to the baseline value in vitamin D deficient non-treated group (P=0.001) whereas, in vitamin D treated group, improvement of BPPV remained stable and unchanged over the study period. CONCLUSION: This study indicates that correction of vitamin D deficiency in BPPV provides additional benefit to rehabilitation therapy (Epley maneuver) regarding duration of improvement. These findings suggest serum 25-OHD measurement in recurrent BPPV.

Short-term galvanic vestibular stimulation promotes functional recovery and neurogenesis in unilaterally labyrinthectomized rats.

Current experimental research on the therapeutic effects of galvanic vestibular stimulation (GVS) has mainly focused on neurodegenerative disorders. However, it primarily stimulates the vestibular nuclei and could be potentially effective in modulating imbalance between them in the case of unilateral labyrinthectomy (UL). Fifty male Wistar rats (180-220g) were used in 5 groups of 10: intact, sham, right-UL (RUL; without intervention), and two other right-UL groups with GVS intervention [one group treated with low rate GVS (GVS.LF; 6-7Hz), and the other treated with high rate GVS (GVS.HF; 17-18Hz)]. The UL models were prepared by intratympanic injection of sodium arsanilate. GVS protocols were implemented 30min/day and continued for 14 days via ring-shaped copper electrodes inserted subcutaneously over each mastoid. Functional recovery was assessed by several postural tests including support surface area, landing and air-righting reflexes, and rotarod procedure. Immunohistochemical investigations were performed on ipsi- and contra-lesional medial vestibular nuclei (MVN) using bromodeoxyuridine (BrdU) and Ki67, as markers of cell proliferation. Behavioral evaluations showed significant functional recovery of GVS-treated groups compared to RUL group. The percent of marked cells with BrdU and Ki67 were significantly higher in the ipsilesional MVN of both GVS-treated groups compared with other groups. Our findings confirmed the effectiveness of GVS-intervention in accelerating static and dynamic vestibular compensation. This could be explained by the cell proliferation in ipsilesional MVN cells and rapid rebalancing of the VNs and the modulation of their motor outputs. Therefore, GVS could be promising for rehabilitating patients with unilateral vestibular weakness.

Effects of Hyperlipidemia on Noise Induced Hearing Loss (NIHL).

Likelihood of developing noise induced hearing loss (NIHL) is affected by some factors such as genes, nutrition and healthy hearing habits. We investigated this study to determine the effect of hyperlipidemia on NIHL. In a case-control study, 144 workers who exposed to continuous noise more than 85 dBA (88-89 dBA) from a textile factory in Tehran were examined. Serum Blood test results as index for dyslipidemi, were collected and audiometry tests were carried out to analyze the association of hyperlipidemian and NIHL. The mean ±SD of Cholesterol level for NIHL and control were 188.19 (28.46) and 159.00 (26.66) mg/dL respectively. Also the mean ±SD of Triglyceride level for NIHL and control were 203.75 (53.92) and 105.00 (30.50) mg/dL consecutively. After adjusting odds ratio (OR) for NIHL, only hypertriglyceridemia had association with NIHL. (aOR = 1.07; 95 % CI 1.04-1.10), and there wasn't any relation between hypercholestomia and NIHL (aOR = 1.02; 95 % CI 0.99-1.05). Workers with hypertriglyceridemia are at increased risk for NIHL. In factories with elevated noise levels, besides hearing conservation programs, attention to blood serum level of workers and healthy diet are proposed to help in preserving hearing threshold.

Auditory Brainstem Response Improvements in Hyperbillirubinemic Infants.

BACKGROUND AND OBJECTIVES: Hyperbillirubinemia in infants have been associated with neuronal damage including in the auditory system. Some researchers have suggested that the bilirubin-induced auditory neuronal damages may be temporary and reversible. This study was aimed at investigating the auditory neuropathy and reversibility of auditory abnormalities in hyperbillirubinemic infants. SUBJECTS AND METHODS: The study participants included 41 full term hyperbilirubinemic infants (mean age 39.24 days) with normal birth weight (3,200-3,700 grams) that admitted in hospital for hyperbillirubinemia and 39 normal infants (mean age 35.54 days) without any hyperbillirubinemia or other hearing loss risk factors for ruling out maturational changes. All infants in hyperbilirubinemic group had serum bilirubin level more than 20 milligram per deciliter and undergone one blood exchange transfusion. Hearing evaluation for each infant was conducted twice: the first one after hyperbilirubinemia treatment and before leaving hospital and the second one three months after the first hearing evaluation. Hearing evaluations included transient evoked otoacoustic emission (TEOAE) screening and auditory brainstem response (ABR) threshold tracing. RESULTS: The TEOAE and ABR results of control group and TEOAE results of the hyperbilirubinemic group did not change significantly from the first to the second evaluation. However, the ABR results of the hyperbilirubinemic group improved significantly from the first to the second assessment (p=0.025). CONCLUSIONS: The results suggest that the bilirubin induced auditory neuronal damage can be reversible over time so we suggest that infants with hyperbilirubinemia who fail the first hearing tests should be reevaluated after 3 months of treatment.

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.

Iranian Version of Speech, Spatial, and Qualities of Hearing Scale: A Psychometric Study.

Evaluation of communication abilities in the elderly is crucial for activities which will be performed to improve their quality of life. A valid and reliable questionnaire is needed for assessing communication abilities. We aimed to translate and validate the speech, spatial, and qualities of hearing scale (SSQ) in Iran. The forward-backward procedure was applied to translate the questionnaire from English into Persian. After linguistic validation and pilot study, a cross-sectional study was carried out, and psychometric properties of the Iranian version of the SSQ were tested. Number of 333 elderly individuals with impaired hearing completed the questionnaire. Number 48.3% were hearing aid users and 51.7% was not. Reliability was assessed by internal consistency (Cronbach's alpha) and test-retest analysis. Exploratory factor analysis was performed for extracting factor structure of the Persian version of SSQ. Confirmatory factor analysis was performed to compare different models of factor loadings. The Mean age of participants was 62.00 years (SD=9.58 years), and the mean SSQ score was 5.1 (SD=1.2, ranged: 3.17-6.27). Reliability evaluation revealed high internal consistency and good test- retest reliability. Cronbach's alpha coefficient was 0.96 and the Pierson Correlation at test-retest analysis was 0.73 for Quality of hearing factor, 0.88 for Spatial and o.73 for Speech understanding factor. The results of exploratory factor analysis (EFA) indicated a four-factor solution for P-SSQ that jointly accounted for 52.40% of the variance observed. Confirmatory factor analysis approved the three factor solution but proposed a possible fourth factor. The Iranian version of the SSQ has acceptable psychometric properties, and it will be helpful for assessing different kinds of communication abilities in the Iranian elderly population.