EDITORIAL

Background and Aim: Disequilibrium is a common complaint in the elderly. The activities-specific balance confidence (ABC) scale is a suitable tool for assessing the level of confidence in balance whilst performing daily activities. The purpose of the study was translation, cultural adaptation and evaluation of the reliability and validity of the Activities-Specific Balance Confidence Scale for elderly Persians.
Methods: This was a descriptive, cross-sectional (test development) study. The ABC scale was translated based on the native protocol of the international quality of life assessment and was adapted to conditions found in Iranian culture. Upon confirmation of face validity, the questionnaire was given to 142 Persians aged between 60 and 92 years, selected via simple sampling. After one week, 56 participants were asked to complete the questionnaire again. Finally, reliability was evaluated using internal consistency and test-retest reproducibility.
Results: Three items out of 16 were modified to adapt the scale to Iranian culture. Changes were approved by the original author. Reliability was confirmed using a Cronbach alpha coefficient of 0.96 and an Intraclass correlation coefficient of 0.97.
Conclusion: The Persian version of the ABC scale is equivalent to the original content of the scale. In addition, it is compliant with the terms of Persian culture. It has high validity and reliability. It is suitable for assessing the level of balance confidence in the elderly in clinical or research settings.

Background and Aim: Sinusoidal harmonic acceleration (SHA) test is one of the most effective and best-tolerated methods to assess vestibular system function, especially horizontal semicircular canal in children. A prerequisite for using this test in children, is the availability of normative data. Despite of the numerous studies related to the SHA in adults, few researches have been documented in children. The aim of this study was to obtain normal values for SHA responses in normal children.
Methods: In this cross-sectional study, 38 children (20 boys and 18 girls) between 7 to 12 years old (mean age=9.55, SD=1.71) with normal hearing and no history of vestibular dysfunction were enrolled. SHA test was performed in five frequencies (0.01, 0.02, 0.08, 0.16 and 0.32 Hz) and fixation suppression test was performed in two frequencies (0.16 and 0.32 Hz). Parameters of gain, phase and symmetry in SHA test and fixation index (FI) in visual fixation suppression test in each frequency were recorded and compared tow genders.
Results: SHA responses and visual fixation suppression results were recorded in all children. Effect of frequency in each parameters of gain and phase were shown to have statistical significant differences, that is with increasing of frequency, gain increases and phase decreases (p≤0/001).
Conclusion: In this study normative values for SHA test and visual fixation suppression responses were proposed. These normative data can be used in the assessment of balance disorders and dizziness in school age children.

Background and Aim: Dichotic listening evaluation is one of the most common behavioral procedures for assessing the cerebral dominance of language and is considered as the main component of the auditory processing test battery in children and adults. The randomized dichotic digits test (RDDT) has two lists of randomly distributed one-, two-, and three-digit items. This research was performed for studying the inter-list equivalency and test-retest reliability of Persian RDDT.
Methods: Persian RDDT was administered at 50 dBHL on 62 right-handed individuals (equal sex ratio) with normal hearing sensitivity in the age range of 12-45 years. The interval between the test sessions was 30 days and each session had two test rounds with an interval of 20 minutes. In each session, list 1 of the Persian RDDT was performed for the first round and list 2 performed for the second round.
Results: Results demonstrated that mean right and left ear score and ear advantage of Persian RDDT list 1 and list 2 had no statistically significant difference (right ear p=0.25, left ear p=0.56, ear advantage: p=0.6). Intra-class correlation coefficient of scores in the first and the third test rounds (list 1) for the right and left ears were 0.71 and 0.68, and for the second and the fourth test rounds (list 2) were 0.69 and 0.80, respectively.
Conclusion: Based on the results of this study, it would seem that the two lists of Persian RDDT are equivalent and the mean scores have good to excellent test-retest reliability.

Background and Aim: This study investigated whether objective temporal processing paradigms including voice-onset-time, speech-in-noise, and amplitude modulated-broad-band noise (AM-BBN) are sensitive to disrupted temporal processing in elderly listeners with normal hearing (age-related-temporal processing deficit).
Methods: We evaluated 15 adults aged 64–80 years using behavioural measures of temporal processing temporal modulation transfer function (TMTF) and speech perception. Cortical auditory evoked potentials (CAEPs) were elicited by three temporal paradigms presented in the sound field at 65 dBSPL: (1) naturally produced stop consonant-vowel (CV) syllables /da/-/ta/ and /ba/-/pa/; (2) speech-in-noise stimuli using the speech sound /da/with varying signal-to-noise ratios (SNRs); and (3) 16 Hz amplitude-modulated (AM) BBN presented in two conditions: (i) alone (representing a temporally modulated stimulus) and (ii) following an unmodulated BBN (representing a temporal change in the stimulus) using four modulation depths.
Results: Findings demonstrated a statistically significant mean difference in n1 latency (p<0.05) between normally hearing elderly and young adult listeners in all paradigms. Compared with young adult participants, n1 latency of the CAEP was always prolonged for elderly participants.
Conclusion: The three developed temporal processing paradigms are sensitive to disrupted temporal processing in elderly participants, and n1 latency may serve as a reliable objective measure of the efficiency of auditory temporal processing. The aging process affects temporal representations of the acoustic stimulus and reduces the ability to detect temporal cues, evidenced by abnormal n1 latency.

Background and Aim: Creatine is an energy-supplying protein in neuromuscular system with a protective role in relieving neurological symptoms. Since the enzymes and other mechanism involved in the conversion of creatine in the inner ear and vestibular nuclei are found in abundance, the aim of this study was to measure the effects of creatine on cervical vestibular evoked myogenic potentials (cVEMP) parameters.
Methods: In this double-blind study, 35 healthy males aged 20-25 were randomly divided into an interventional (given creatine monohydrate) and a placebo groups (given maltodextrin). Participants received 5 g of dissolved powders in 250 ml water 4 times/days for 5 consecutive days. Cervical myogenic potentials were recorded before and after intervention with 500 Hz tone burst in 95 dBnHL.
Results: In intervention group, cVEMP amplitudes increased from 41.86 to 55.71 μV and p13 and n23 latencies decreased from 13.81 and 22.61 to 13.32 and 21.69 ms, respectively. Also thresholds decreased from 85.52 to 81.71dBnHL. All changes were statistically significant (p<0.05).
Conclusion: The improvement of VEMP parameters following consumption of creatine supplement is likely due to increased sensitivity of saccule and vestibulocolic reflex pathway in normal subjects and maybe beneficial to patients with vestibular disorders.

Background and Aim: Bilingualism is an important phenomenon with different effects on each aspect of language processing. Auditory temporal processing is a major component of the auditory processing ability. Since bilingual and monolingual individual’s brain process are different, and no studies have yet been conducted on the effect of temporal processing on speech recognition performance of Azeri-Persian bilinguals, the purpose of the present study is the comparison of auditory temporal processing between Persian monolinguals and early Azeri-Persian bilinguals.
Methods: In this cross-sectional study, the Persian version of time compressed speech test was performed with monosyllabic words in three compression rates of 0, 40 and 60 percent in the most comfortable level in each ear, separately. The subjects were 36 Persian monolinguals and 36 Azeri-Persian bilinguals aged from 18 to 30 and were analyzed based on languages’ compression rate and ear factors.
Results: The speech recognition scores (SRS) in both groups were decreased by increasing compression rate and a significant difference was shown between mean SRS of the two studied groups (p<0.0001). There was no significant difference between three compression rates by the ear (p>0.05).
Conclusion: In compression rate of 40 percent, bilingual group had lower speech recognition ability in comparison with monolingual group. In addition, there was more significant difference when compression rate increases from 40 to 60 percent.

Background and Aim: Respiratory distress syndrome (RDS) is a lung disorder, which can damage the auditory brainstem pathways because of hypoxia. The aim of this study was to evaluate brainstem auditory electrophysiology changes of neonates with RDS.
Methods: fifteen term neonates who suffered from RDS, 15 term neonates admitted in the NICU for any reason except RDS, and 15 normal term neonates as control group were studied from June to November 2014. Auditory brainstem response (ABR) was recorded by clicks, delivered at 80 dBnHL, the polarity was alternative, the band pass filter and the time window were 50-2000 Hz and 15ms with total 2000 sweeps, respectively. Data were analyzed by ANOVA and paired t-test using SSPS18.
Results: The absolute latencies of waves I, III, V and I-III, I-V intervals of both ear in RDS group and the participants admitted in NICU were significantly longer than controls (p=0.00).
Conclusion: Hypoxia and asphyxia due to RDS can damage the auditory brainstem pathways in neonatal period; additionally, the neonates who were admitted in NICU are also at the risk of auditory brainstem deficit. The findings shed light on the importance of assessing the auditory brainstem function in neonates who had RDS and who were admitted in NICU.