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Background and Aim: Bilingualism, as one of the discussing issues of psychology and linguistics, can influence the speech processing. Of several tests for assessing auditory processing, dichotic digit test has been designed to study divided auditory attention. Our study was performed to compare the auditory attention between Iranian bilingual and monolingual young adults.

Methods: This cross-sectional study was conducted on 60 students including 30 Turkish-Persian bilinguals and 30 Persian monolinguals aged between 18 to 30 years in both genders. Dichotic digit test was performed on young individuals with normal peripheral hearing and right hand preference.

Results: No significant correlation was found between the results of dichotic digit test of monolinguals and bilinguals (p=0.195), and also between the results of right and left ears in monolingual (p=0.460) and bilingual (p=0.054) groups. The mean score of women was significantly more than men (p=0.031).

Conclusion: There was no significant difference between bilinguals and monolinguals in divided auditory attention and it seems that acquisition of second language in lower ages has no noticeable effect on this type of auditory attention.

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Background and Aim: Time compressed speech test is one of the most common types of monaural central auditory processing tests assesses the temporal resolution. The aim of the present study was to evaluate the impact of compression rate and sex on results of this test among the young individuals with normal hearing.

Methods: The Persian version of time compressed speech test with six lists of 25 monosyllabic words was prepared in three compression rates of 0, 40 and 60 percent. 36 young people with normal hearing and age range of 18 to 30 years were assessed with time compressed speech test in the most comfortable level in each ear separately. Then scores were compared between two ears, genders and three compression rates.

Results: There was a significant difference between word recognition scores of three compression rates (p<0.0001). Significant difference was revealed between word recognition scores of both ears, just in the 60% compression rates. No significant difference was found between the word recognition scores of the two genders.

Conclusion: Word recognition scores decreases with increase of the presentation rate of speech stimuli. Time compressed speech test accompany with other audiologic tests can be used to examin the auditory temporal processing and speed of speech processing as a test battery.

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Background and Aim : Learning and memory are two high level cognitive performances in human that hearing loss influences them. In our study, mini-mental state examination (MMSE) and Ray auditory-verbal learning test (RAVLT) was conducted to study cognitive stat us and lexical learning and memory in deaf adults using sign language.

Methods: This cross-sectional comparative study was conducted on 30 available congenitally deaf adults using sign language in Persian and 46 normal adults aged 19 to 27 years for both sexes, with a minimum of diploma level of education. After mini-mental state examination, Rey auditory-verbal learning test was run through computers to evaluate lexical learning and memory with visual presentation.

Results: Mean scores of mini-mental state examination and Rey auditory-verbal learning test in congenitally deaf adults were significantly lower than normal individuals in all scores (p=0.018) except in the two parts of the Rey test. Significant correlation was found between results of two tests just in the normal group (p=0.043). Gender had no effect on test results.

Conclusion: Cognitive status and lexical memory and learning in congenitally deaf individuals is weaker than in normal subjects. It seems that using sign language as the main way of communication in deaf people causes poor lexical memory and learning.

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Background and Aim: Preterm birth is one of the risk factors need comprehensive audiological assessment. In this study, the effect of sex and rate of stimulation on response of children with history of preterm birth was investigated by auditory brainstem response (ABR).

Methods: This cross-sectional study was conducted using convinience sampling. Click-evoked a uditory brainstem response test with both low (21.1 c/s) and high (51.1 c/s) stimulus rates was recorded in 30 children with a history of preterm birth and 30 ones with history of term labor, as controls.

Results: Significant differences were observed in inter-peak latencies of I-III in both rates, III-V in the low rate, I-V in the high rate, and absolute latency of III wave between high and low stimulus rates (p<0.05 for all). Rate of stimulus affect on auditory brainstem response of preterm birth group was more than controls. Sex also affected on some parameters of auditory brainstem response test.

Conclusion: Preterm birth group showed longer latencies than normal group in both rates. Rate of stimulus had significant effect on results of children with history of preterm birth compared normal group. These findings may reflect the negative effect of preterm birth on neural synchronization function in response to transient stimuli.

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Background and Aim: Dichotic listening means presentation of two different auditory stimuli to each ear simultaneously. This study deals with the development of Persian version of Bergen dichotic listening test and its preliminary results on auditory attention and language laterality in adults with normal hearing.

Methods: Persian version of the Bergen dichotic listening test was instructed by six consonant-vowel syllables to evaluate three conditions of non-forced attention, attention to right and attention to left ears separately. Then, it was performed on 54 right-handed young adults with normal hearing and the mean age of 23.24 (SD=2.78) years from both genders.

Results: Frequency of correct response in the right ear was higher significantly in two conditions of non-forced attention (83.3%) and attention to the right ear (98.1%), and also was higher significantly in the left ear (-79.6%) in attention to the left (p<0.0001). Laterality index was 31.33% in non-forced attention, 73.30% in attention to the right and -37.50% in attention to the left which was significantly different (p<0.0001).

Conclusion: Right ear advantage was revealed in non-forced attention that was altered with selective attention to the right and left remarkably result from the effect of top-down processing of brain cortex on bottom-top processing of speech stimulus. These preliminary results showed the performance of Bergen dichotic listening test to test auditory attention and language laterality.

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Background and Aim: Behavioral audiometry is the best method of hearing evaluation. Hearing thresholds are estimated with auditory evoked responses in patients who are not able to cooperate in behavioral audiometry. Because rehabilitative decisions are based on behavioral thresholds, it is essential to determine the amount of difference between behavioral and evoked response thresholds. The purpose of this study was to evaluate the difference between functional and auditory steady-state response (ASSR) gains.

Methods: Twenty six moderate to severe hearing impaired adolescents and adults (age range: 14 to 55 years) participated in this interventional-comparative study. Audiometery and ASSR testing was performed (without hearing aid and then with hearing aid). Finally, functional gain with ASSR gain, and behavioral thresholds with ASSR thresholds were compared using paired t-test and correlation statistical methods. All tests were performed in the sound field.

Results: The mean difference was 6.19 dB between unaided behavioral and ASSR thresholds, 4.33 dB between aided thresholds, and 2.43 dB between functional and ASSR gains. There was no significant difference between functional and ASSR gains (p>0.05).

Conclusion: The difference between functional and ASSR gains is less than the difference between behavioral and ASSR thresholds and it has less variability between different frequencies. So, it may be better to use ASSR gain instead of ASSR thresholds in hearing aid fitting in difficult-to-test population.

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Background and Aim: Concerning the important role of parents of hearing-impaired children in auditory-verbal therapy, this study mainly focused on preparing a Persian version of the “Parental needs questionnaire” and analyzing its validity and reliability.

Methods: First, the original English version of the questionnaire “the needs of hearing-impaired Children’s Parents in Auditory-Verbal Therapy” translated to Persian, based on the approved translation protocol of International Quality of Life Assessment by world health organization. Then, the Persian version presented to seven experts for validating the content and their feedbacks were applied into the questionnaire. Finally, the questionnaire presented to parents of 51 hearing-impaired children who attend in auditory-verbal therapy, and the collected results were analyzed statistically.

Results: The overall mean of content validity index in 32 items of the questionnaire was 0.87. The overall Cronbach’s alpha of this questionnaire was 0.86 in the test and 0.99 in the re-test phases.

Conclusion: Based on the obtained results, the Persian version of the questionnaire has a satisfactory content validity and reliability and could be used in clinics and medical centers for analysis of parental needs.

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Background and Aim: Studies have shown that long-term use of monaural hearing aid in symmetrical hearing losses may lead to physiological changes. In this research, the possibility of plasticity occurrence in bilaterally hearing impaired listeners fitted with only one hearing aid was investigated.

Methods: Our study was carried out on 12 elderly listeners with a mean age of 61.92 years who had symmetrical moderate to severe sensory neural hearing loss in both ears. All of the participants had minimum monaural hearing aid experience of 2 years. We used auditory brainstem response (ABR) testing in order to compare absolute latency and amplitude of wave V between the two ears of cases. Air conduction click stimuli were presented monaurally at 80, 90 and 100 dB nHL.

Results: Despite the shorter absolute latency of wave V in the fitted ear, no significant difference was found between the two ears (p>0.389). The difference between wave V amplitude of both ears was greater in 90 dB nHL level (p=0.043). Women showed shorter mean latency than men and the mean amplitude of women was greater than men. Significant gender difference was observed in absolute latency of wave V (p<0.037).

Conclusion: Our findings indicate that the use of monaural hearing aid in symmetrical hearing losses can induce neural plasticity within auditory brainstem pathways which can be displayed by auditory brainstem response test.

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Background and Aim: Memory is one of the aspects of cognitive function which is widely affected among aged people. Since aging has different effects on different memorial systems and little studies have investigated auditory-verbal memory function in older adults using dichotic listening techniques, the purpose of this study was to evaluate the auditory-verbal memory function among old people using Persian version of dichotic auditory-verbal memory test. Methods: The Persian version of dichotic auditory-verbal memory test was administered to 23 old people ranging 60-80 years and 30 young people aging 20-30 years, with normal and symmetric hearing in both ears. The performance of the two groups was compared. Results: The mean score of young (6.36±0.43) and old (4.58±0.74) adults on dichotic auditory-verbal memory test were significantly difference (p=0.001). The correlation test showed a negative correlation between age and the memory scores in aged people (r=0.36). A significant difference in recall of early (p=0.034), middle (p=0.037), and final (p=0.041) words was seen between aged and young people. Conclusion: Based on the obtained results, significant reduction in auditory memory was seen in aged group and the Persian version of dichotic auditory-verbal memory test, like many other auditory verbal memory tests, showed the aging effects on auditory verbal memory performance.

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Background and Aim: Multiple sclerosis (MS) is one of the central nervous system diseases can be associated with a variety of symptoms such as hearing disorders. The main consequence of hearing loss is poor speech perception, and temporal acuity has important role in speech perception. We evaluated the speech perception in silent and in the presence of noise and temporal acuity in patients with multiple sclerosis.

Methods: Eighteen adults with multiple sclerosis with the mean age of 37.28 years and 18 age- and sex- matched controls with the mean age of 38.00 years participated in this study. Temporal acuity and speech perception were evaluated by random gap detection test (GDT) and word recognition score (WRS) in three different signal to noise ratios.

Results: Statistical analysis of test results revealed significant differences between the two groups (p<0.05). Analysis of gap detection test (in 4 sensation levels) and word recognition score in both groups showed significant differences (p<0.001).

Conclusion: According to this survey, the ability of patients with multiple sclerosis to process temporal features of stimulus was impaired. It seems that, this impairment is important factor to decrease word recognition score and speech perception.

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Background and Aim: Speech-evoked auditory brainstem responses were used in the assessment of subcortical encoding of the speech stimuli in the English language. These processes are affected by language background and experiences. Considering the language specific acoustic differences, the aim of current study was establishing the response norms in adult Persian-speakers and comparing the encoding of the speech syllable /da/ between Persian and English languages.

Methods: Auditory brainstem responses to speech syllable /da/ in the right ear, gained from 48 normal adults (25 women and 23 men) with the mean age of 22.70 with SD 2.05 years were recorded. After characterizing the onset elements, transition from consonant to vowel, the periodic portion and offset of response, the Persian dataset were compared with 95% confidence interval norms in the age range of 18-28 years.

Results: The response to speech syllable /da/ was successfully recorded in all of the subjects and main features of response were highly overlapped with published English norms.

Conclusion: Normative values for speech-evoked auditory brainstem responses in adult Persian speakers are presented in the current survey. Our findings suggest that the recommended procedure and more importantly, the scoring method based on English norms can be used in Persian speakers without replacing the original synthetic vowel /da/.

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Background and Aim: Music exists in all cultures many scientists are seeking to understand how music effects cognitive development such as comprehension, memory, and reading skills. More recently, a considerable number of neuroscience studies on music have been developed. This study aimed to investigate the effects of null and positive background music in comparison with silence on auditory-verbal memory performance.

Methods: Forty young adults (male and female) with normal hearing, aged between 18 and 26, participated in this comparative-analysis study. An auditory and speech evaluation was conducted in order to investigate the effects of background music on working memory. Subsequently, the Rey auditory-verbal learning test was performed for three conditions: silence, positive, and null music.

Results: The mean score of the Rey auditory-verbal learning test in silence condition was higher than the positive music condition (p=0.003) and the null music condition (p=0.01). The tests results did not reveal any gender differences.

Conclusion: It seems that the presence of competitive music (positive and null music) and the orientation of auditory attention have negative effects on the performance of verbal working memory. It is possibly owing to the intervention of music with verbal information processing in the brain.