Background and Aim: Following an early visual deprivation, the neural network involved in processing auditory spatial information undergoes a profound reorganization. In order to investigate this process, event-related potentials provide accurate information about time course neural activation as well as perception and cognitive processes. In this study, the latency and amplitude of auditory P300 were compared in sighted and early blind individuals in age range of 18-25 years old.

Methods: In this cross-sectional study, auditory P300 potential was measured in conventional oddball paradigm by using two tone burst stimuli (1000 and 2000 Hz) on 40 sighted subjects and 19 early blind subjects with mean age 20.94 years old.

Results: The mean latency of P300 in early blind subjects was significantly smaller than sighted subjects (p=0.00.( There was no significant difference in amplitude between two groups (p>0.05).

Conclusion: Reduced latency of P300 in early blind subjects in comparison to sighted subjects probably indicates the rate of automatic processing and information categorization is faster in early blind subjects because of sensory compensation. It seems that neural plasticity increases the rate of auditory processing and attention in early blind subjects.

Background and Aim: Children with speech and language disorders can have reduced diadochokinesis (DDK) rates. Although a relationship has been proposed between DDK and the rate of speech, there is no consensus among the experts and its credibility remains questioned. The purpose of this study was to compare oral DKK with the rate of speech and reading in normal students.

Methods: One hundred second grade female students participated in this descriptive-comparative study. The subjects were asked to read a text of their book, tell a story, and perform some oral DDK tasks. The elapsed time was measured by Cool Edit software. Descriptive statistics were used to describe the data. Data analysis was performed using Student t-test.

Results: Time history durations of DDK tasks /tâ/, /pâ/ and /kâ/ were 4.10, 4.15 and 4.74 ms, respectively. The rate of reading was 3.1 syllables per second and rate of talking was 2.8 syllables per second. No relationship between the rate of speech and DDK was found, still, we found a significant association between the reading rate and DDK in /kâ/ (p=0.03) and /pâtâkâ/ (P<0.01).

Conclusion: Relevant DDK tasks can be utilized in order to improve the reading rate. Reading rate was higher than speech rate and the rate of bilabial diadochokinesis in mono syllables is the highest rate that may be expected during the treatments.

Background and Aim: Recently, more attention was paid to the direct protective effect of aldosterone against hearing impairment in elderly patients. The aim of this study was determination of possible correlation between serum aldosterone level and hearing condition of elderly patients that referred to the Otolaryngology services of Hamadan in 2005-2006.

Methods: In this case control study 54 (27 males,27 females) persons above 60 years old were evaluated. They contained twenty eight cases with normal hearing and 26 cases with presbycusis. Persons with any abnormal biochemical finding or history of conditions that predispose them to the sensorineural hearing loss (SNHL) were excluded. In both groups serum level of sodium, potassium and aldosterone were measured and hearing condition evaluated by puretone, speech and immitance audiometry.

Results: Statistical relationship between serum aldostrone level and hearing condition, sex, configuration of audiogram and speech discrimination score (SDS) were not significant. In addition, no significant relationship between sodium and potassium levels with hearing condition was found (p>0.05). Conclusion: This study could not confirm protective effect of aldostrone against presbycusis. This discrepancy may originate from epidemiologic differences, laboratory errors or small sample size.

Background and Aim: phonological awareness skill is an integrated ability that is manifested in 4 skills including syllable, rhyme, and phoneme awareness and alliteration. The aim of the present study is to explore development of syllabic elision skill as an aspect of syllabic awareness.

Methods: It was a descriptive-analytic cross-sectional study. Thirty normal Persian-speaking children, 15 girls and 15 boys, were randomly selected throughout Tehran kindergartens. The participants were monolingual. Children should eliminate a syllable from any word presented, and to state the remaining section of the word. The responses were analyzed using SPSS software.

Results: Ability of 5 to 6 year-old children in eliminating a syllable in two syllabic words was significantly higher than those of three and four syllabic words and syllabic elision of three and four syllable words was significantly different (p=0.000). Two, three and four syllabic task correlations were statistically significant and the correlation between syllabic elision ability and the syllabic construct and the positioning of elision syllable was significant (p<0.05).

Conclusion: Syllabic elision skill blossoms in 5 to 6 year-old Persian-speaking children. The maximum ability of syllabic elision evolves after phonological recoding and after learning reading and writing skills. Syllabic elision ability is also influenced by the syllabic construct and the positioning of elision syllable.

Background and Aim: Reading is undoubtedly an essential skill for everybody in these years. Reading disorders or dyslexia can cause several problems for those who suffer from them. Early assessment and diagnosis play an important role in treatment of this disorder. The main aim of this study was determining the prevalence of reading disorder in first to fifth grade elementary school students. The subbasic aim was introducing the screening Inventory Reading Test (IRT) for diagnosis of the Students with reading disorder at elementary schools.

Methods: A total of 200 students (boys and girls) in five elementary education grades in Isfahan were selected through multi-stage random sampling method and assessed by IRT in 2008. Descriptive statistical analysis was performed using SPSS Software package version 13.0 for Windows.

Results: This survey revealed the highest prevalence of reading disorder in the first grade male students (25%), and the lowest in fifth grade female students (0%). The incidence of dyslexia in all grades generally was 10%. The overall incidence was 66% for male students and 34% for female students.

Conclusion: Reading disorder is more prevalent among male students than female students and the Inventory Reading Test is a satisfactory tool for rapid diagnosis of reading disorder.

Background and Aim: The correlation of stuttering and different linguistic factors is assessed in many studies. The obtained results can pave the way to reach a better understanding of stuttering, as well as finding more appropriate treatments. This study investigates the effect of utterance length on speech dysfluency comparing stuttering Persian(Farsi) -speaking children and nonstuttering ones.
Methods: Ten stuttering and ten nonstuttering Persian-speaking children between 4 and 6 years of age, matched by age and gender where included in this cross-sectional study. All individuals were investigated by ten sets of simple and complex sentences. Morphemes were added one by one to sentences in each set in order to assess the impact of utterance length on dysfluency. Data analysis was performed using SPSS software.
Results: In practicing ten sets of sentences, the speech dysfluency shows significant enhance with increase of utterance length in both stuttering and nonstuttering children (p=0.001). Furthermore, while comparing two groups of simple and complex sentences, significant increase of speech dysfluency was observed by length enhance of utterance, in both stuttering and nonstuttering children (p<0.05). The comparison of stuttering and nonstuttering children showed significant difference between the two groups as well (p=0.001).
Conclusions: The results of this study show that increase in utterance length in both simple and complex sentences lead to increase in dysfluency in stuttering and nonstuttering children. Stuttering children indicated more dysfluency than nonstuttering ones.

Background and Aim: listening, speaking, reading and writing are considered the lingual skills. These skills are in direct relation with each other. Listening is the first skill learnt by the individual through development. If damaged by hearing impairment, listening can cause serious defect to lingual skills. The goal of our research was to study the effect of hearing loss on reading literacy in hearing impairment students in comparison with normal hearing students.
Methods: Study was performed using the examination booklets of Progress in International Reading Literacy Study (PIRLS) 2001. 119 hearing impairment students of 4^th grade primary school, last year guidance school, and last year high school levels in schools providing exceptional student education were included. These individuals were compared to 46 normal hearing students of 4^th grade primary school of ordinary schools. Comparative statistical analysis was performed using t-test.
Results: Reading literacy and literal contents understanding was shown to have a significant difference between normal hearing and whole hearing impaired student (p<0.05), except the ones in high school level with moderate hearing loss. There was also seen a significant difference between normal hearing and hearing impairment students in understanding of information contents (p=0.03).
Conclusion: Hearing loss has a negative effect on reading literacy. Consequently, curriculum change and evolution of educational programs in exceptional centers is needed, in order to promote reading literacy and to enhance rest hearing

Background and Aim: Evaluation of hearing-impaired children&aposs auditory skills by a valid test is very important before starting auditory training. There are many different tests available for languages other than Persian, and some limited Persian tests for children above 5 year of age as well. Accordingly considering the importance of early intervention, we aimed to design a test for evaluating auditory skills of 3-4 year-old hearing-impaired Persian (Farsi) children, which is not available to date.
Methods: The study method was test (scale) construction. The test named Tavana includes four subtests: detection, discrimination, identification and sentence comprehension. For determining content validity of the test, the vocabulary of 3-4 year-old normal-hearing and hearing-impaired children and also the comments of seven specialists were applied. We classified 10,10,8 and 6 sub skills for 1^st to 4^th subtests, respectively.
Results: The content validity of Tavana test&aposs subskills were 100%, 83%, 96% and 95%, respectively (mean=94%). Mean time for test performance was 82 minutes.
Conclusion: Content validity of Tavana test was 94% which was statistically valid compared to Modarres test (97%) and Mazaheryazdi test (88%).

Background and Aim: Reflux laryngitis is extremely common among patients with voice disorder. Medical therapy approaches are not efficient enough. The main goal of this study is to assess the acoustic and laryngeal characteristics of patients with dysphonia before and after medical or voice therapy, and to evaluate the effectiveness of each.
Methods: In this retrospective study, 16 reflux laryngitis patients were assessed. Five received complete voice therapy, tow ceased voice therapy and nine received medication. Perceptual voice evaluation was performed by a speech-language pathologist, the severity of voice problem was calculated, based on the affected acoustic and laryngeal characteristics pre- and post-treatment.
Results: Post-treatment evaluation in patients who received complete voice therapy indicates 80 percent improvement in the severity of disorder and 100 percent improvement in the perceptual voice evaluation. After medical therapy, we observed that voice disorder and perceptual voice evaluation are improved 44 and 66 percent respectively. The improvement was statistically significant in both treatment approaches: complete voice therapy (P=0.039) and medical therapy (p=0.017).
Conclusion: In patients with reflux laryngitis, most acoustic and laryngeal characteristics were normal and satisfying after the treatment. It can be concluded that the proficiency of voice therapy in improving the acoustic and laryngeal characteristics is comparable to medical therapy.

Background and Aim: Laryngeal muscles contribute in sound production play a key role in specific language. Needle electromyography is the specific complementary method for muscle activity evaluation which is awfully painful and needs serenity of patient. The purpose of this study was to use Surface electromyography as a probable new approach for evaluation of laryngeal muscles activity.
Methods: 34 healthy women and 34 healthy men aged 20-30 years old were enrolled in this study. Each individual was seated in an armchair. Recording electrodes were placed bilaterally (right and left) in the low anterior neck at approximately one centimeter from midline on thyroarytenoid and cricothyroid muscles. Silent activity and fricative voice (/z/ , /ž/) and voiceless (/s/ , /š/) activities were recorded for ten seconds followed by 10 seconds of rest, for 5 repetition. All data were processed and frequency and non linear measurements were assessed. And were compared in time and frequency domain.
Results: Muscle activity in fricative voice in both groups was greater than rest condition (p<0.05). Moreover, muscle activity median frequency was significantly more in men than women (p<0.001).
Conclusion: Activity evaluation of thyroarytenoid and cricothyroid muscles using surface electromyography is difficult in women. That may be due to anatomical features such as length and width of neck in women.

Background and Aim: The voice of human being changes during lifetime with different patterns in males and females. In addition to assessment of changes due to aging, some studies examined the voice changes among various languages and ethnical groups. This study is performed to evaluate the fundamental frequency changes in normal 9-50 year-old Persian (Farsi) speaking individuals.
Methods: In this cross-sectional study, 320 voice samples in normal voiceless environment were recorded. The mean of fundamental frequency of vowels and counting is measured by Dr Speech software (real analysis program). Data analysis was performed by MANOVA test and the profiles of their changes were plotted.
Results: The profile of mean of fundamental frequency changes was different in males and females. The mean of fundamental frequency was equal in both genders until 13 years old and the samples of voice had low pitch (Mean: higher than 200 Hz). MFF after 13 years old significantly decreased in males specially in vowels (p<0.001). The changes in vowels and counting were similar. The mean of fundamental frequency in both genders, between 20-40 years old had  relative constancy.
Conclusion: The mean of fundamental frequency changes of vowels and counting in females and males result from diverse dimensions of larynx and other anatomical differences. Significant changes of mean of fundamental frequency in both genders after 13 years old result from puberty in males. The proportional consistence of mean of fundamental frequency between 20-40 years old is probably due to the uniformity of body in this age range.

Background and Aim: Rhyme awareness is an important criterion for speech, language and writing processing. In Iran, there is no auditory tasks of rhyme awareness available for assessment of 5-6 year-old Persian-speaking children. The aim of this study was to develop and to evaluate Persian rhyme awareness tasks in 5-6 year-old Persian-speaking children.
Methods: A hundred normal 5-6 year-old Persian-speaking children (50 girls and 50 boys) were randomly selected. The two rhyme awareness tasks of this study were rhyme detection and rhyme production. The validity and reliability of these tasks were studied by content validity index, intraclass correlation coefficient, and standard error of measurement. The correlation between tasks was studied by Pearson correlation and the mean scores of two sections were compared by easiness level method. The comparison of mean scores of girls and boys were evaluated by independent t-test.
Results: The results showed that the proposed tasks had appropriate validity and reliability. The ability of children in production section was significantly more than in detection section. The correlation of each of two sections with total tasks was significant (p<0.05). In addition, the mean scores of girls and boys were not statistically different (p>0.05).
Conclusions: The proposed tasks are appropriate for assessment of rhyme awareness skills with appropriate validity and reliability in both genders. Two Sections of the tasks had significant correlations and influence on together. The abilities of girls and boys were the same.

Background and Aim: Main feature of auditory processing abilities is temporal processing including temporal resolution, temporal ordering, temporal integration and temporal masking. Many studies have shown the superiority of musicians in temporal discrimination over non-musicians. In this study we compared temporal processing in musicians and non-musician controls via Gap in Noise (GIN) test.
Methods: This cohort study was conducted on 24 musicians with mean age of 25.3 years and 24 normal hearing non-musician controls with mean age of 24.5 years, in Faculty of Rehabilitation of Tehran University of Medical Sciences. GIN test results (approximate threshold and percent of corrected answers) obtained and analyzed by Mann-Whitney non-parametric statistical test.
Results: There was significant difference between approximate threshold and percent of corrected answers between musicians and non-musician group (p<0.001), while no sex difference was observed between both groups (p>0.05).
Conclusion: the lower approximate threshold and the more corrected answers in GIN test by musician group indicate rapid auditory temporal processing ability of this group rather than non-musicians group. This might be related to effects of musical training on central auditory processing.

Background and Aim: Reading skill is one of the most important necessities of students&apos learning in everyday life. This skill is referred to the ability of comprehension, comment and conclusion from texts and receiving the meaning of the massage which is composed. Educational development in any student has a direct relation with the ability of the comprehension. This study is designed to investigate the effects of hearing loss on reading comprehension in hearing-impaired students compared to normal-hearing ones.
Methods: Seventeen hearing-impaired students in 4^th year of primary exceptional schools in Karaj, Robatkarim and Shahriyar, Iran, were enrolled in this cross-sectional study. Seventeen normal-hearing students were randomly selected from ordinary schools next to exceptional ones as control group. They were compared for different levels of reading comprehension using the international standard booklet (PIRLS 2001).
Results: There was a significant difference in performance between hearing-impaired and normal- hearing students in different levels of reading comprehension (p<0.05).
Conclusion: Hearing loss has negative effects on different levels of reading comprehension, so in exceptional centers, reconsideration in educational planning in order to direct education from memorizing to comprehension and deeper layers of learning seems necessary.

Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.
Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years) and 30 normal hearing individuals (mean age 24-27 years) as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.
Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48%) from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.
Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

Background and Aim: Vestibular-Evoked Myogenic Potentials (VEMP) is a new vestibular function test that assesses the vestibulospinal pathway.
Although many studies have investigated different inner ear pathologies by using VEMP, the role of this test in brainstem pathologies and demyelinating processes of central nervous system is still remained to be defined and discussed.
The aim of this study was to compare VEMP in multiple sclerosis patients and normal individuals.
Methods: We carried out a cross-sectional study in 21 patients (15 female, 6 male) fulfilling diagnostic criteria of clinically definite multiple sclerosis, and 20 normal individuals (15 female, 6 male). ages ranging from 17 to 50 years old.
The VEMPs was recorded using 500 Hz short tone burst (STB). The p13 and n23 latencies and p13-n23 peak-to-peak amplitude were the studied parameters.
Results: VEMP results were abnormal in 47.6% of patients. P13 latency and p13-n23 peak to peak amplitude in both ears showed significant difference between the two groups (p<0.05). P13 latency was delayed in 14 ears (of nine patients). VEMPs were unilaterally absent in two patients.
Conclusion: VEMPs thus represent a new method of the brainstem in multiple sclerosis disease. VEMP abnormalities in these patients might be due to impairment in vestibulocollic pathway.

Background and Aim: Hearing aid users complain about a phenomenon called "occlusion effect". The aim of this study was to compare the occlusion effect in normal hearing individuals and those with slight and mild sensory neural hearing loss via Real Ear Measurement.
Methods: Sixty volunteers (30 male, 30 female) aged 18-55 years were enrolled in this study. Subjects were instructed to vocalize /e/ and /i/ for 5 seconds. Sound pressure level was measured by a probe- microphone and recorded in the ear canal. Occlusion effect and the frequency in which maximum occlusion effect occurs were obtained for each individuals for further analysis.
Results: The peak of occlusion effect for /e/ was 10.25 dB and 9.77 dB respectively in 751.9 Hz and 542.98 Hz frequencies in female and male individuals. The maximum occlusion effect occurred with 19.03 dB and 19.10 dB for /i/ and in 518.88 Hz and 440.28 Hz in female and male individuals, in respect. In addition, no significant difference was seen among hearing levels and between genders.
Conclusion: The peak of occlusion effect varies significantly among hearing aid users so that the hearing aid must be tuned. Probe-microphone measures will assist in determination where frequency- specific adjustments are needed.

Background and Aim: Learning disability is a term referes to a group of disorders manifesting listening, reading, writing, or mathematical problems. These children mostly have attention difficulties in classroom that leads to many learning problems. In this study we aimed to compare the auditory attention of 7 to 9 year old children with learning disability to non- learning disability age matched normal group.
Methods: Twenty seven male 7 to 9 year old students with learning disability and 27 age and sex matched normal conrols were selected with unprobable simple sampling. 27 In order to evaluate auditory selective and divided attention, Farsi versions of speech in noise and dichotic digit test were used respectively.
Results: Comparison of mean scores of Farsi versions of speech in noise in both ears of 7 and 8 year-old students in two groups indicated no significant difference (p>0.05) Mean scores of 9 year old controls was significant more than those of the cases only in the right ear (p=0.033). However, no significant difference was observed between mean scores of dichotic digit test assessing the right ear of 9 year-old learning disability and non learning disability students (p>0.05). Moreover, mean scores of 7 and 8 year- old students with learning disability was less than those of their normal peers in the left ear (p>0.05).
Conclusion: Selective auditory attention is not affected in the optimal signal to noise ratio, while divided attention seems to be affected by maturity delay of auditory system or central auditory system disorders.

Background and Aim: valid identification, prevention, and treatment of language disorders are a high priority for the speech and language professionals. One method for studying language development is sentence repetition that is faster to implement and analysis than other procedures. The aim of this project was constructing sentence repetition test as a quick measure of grammatical potency in 2.5 to 4 year old children.
Methods: Sentences appropriate for 2.5 to 4 year old children were selected during several stages by speech and language pathologist and linguists. The validity of sentences was assessed by professional masters in this theme. Subsequently, 41 sentences including those with 80% high validity were selected as the test sentences. Appropriate pictures were also provided with sentences. The test was administrated to 72 children in 3 groups (2.5-3, 3-3.5, and 3.5-4 year olds, gender matched). The reliability was administered with a test-retest design across a 2 weeks interval.
Results: Content validity Index for this test was 80%. "Test-retest reliability" was used for reliability of this test. The Interclass correlation coefficient for this test was 0.95 and standard error measurement was 7.45. The average of scores for sentence repetition, between groups was significant (p<0.001, p<0.001, p= 0.014).
Conclusion: This sentence repetition test has the appropriate validity and reliability as well as the capability of proper and quick assessment (screening) of grammatical development in 2.5 to 4 year old Persian speaking children.

Background and Aim: Neuroimaging techniques in audiovisual speech processing are innovative approach to neuroscience investigation that steadily influences the deep survey of highly mechanisms involved in this process. The purpose of this study was to evaluate brain activity via functional magnetic resonance imaging throughout audiovisual speech perception in Persian language.
Methods: Functional MRI was used to assess 19 normal 20-30 year old women while they had been presented syllable /ka/ visually and /pa/ auditory using block design method, in which it would provide two series of imaging, functional and T1-weighted. Subsequently, the results were analyzed and compared by FSL software.
Results: The results of this study pointed out that both middle and cortical regions of brain are activated in visual stimuli and its middle regions are activated in response to auditory stimuli. Hence, left anterior supramarginal, some parts of motor speech system including insular and cingulate cortex-precentral cortex were stimulated with visual stimulus and left posterior supramarginal as well as right supramarginal gyrus were stimulated with auditory stimulus. Moreover, in this investigation, McGurk effect was behaviorally proven in fifteen subjects.
Conclusion: It was hypothesized that the activation of unique region, supramarginal gyrus, with both audio and visual stimuli indicated the presence of commonplace region for phonologic processing of sensory inputs. In addition, auditory stimuli develop more intense activity and on the other hand, broaden-maximum voxel-as well as extra regions are demonstrated in response to visual stimuli. These points represent the unfamiliarity of normal individual brain to percept visual speech stimuli.