Vol 25 No 3 (2016)

Research Article(s)

  • XML | PDF | downloads: 232 | views: 331 | pages: 135-139

    Background and Aim: Human beings receive a variety of sounds in their everyday lives. These sounds are generated by different sources, and are heard simultaneously or with a small time sequence. A characteristic of the auditory system is its ability to analyze complex sounds, and to make decisions about the source of each constituent part of these sounds. The present study intends to assess normative variation of auditory stream segregation in adults.
    Methods: This study has a cross-sectional design and was conducted on 40 normal adults with the age range of 18 to 35. Stimuli were presented in the form of pure tones A and B as ABA-ABA triplet pattern at the intensity level of 40 dBSL. The A tone frequency was selected as the basis at 500, 1000, and 2000 Hz. The B tone was presented with a difference of half to twelve and half semitones above the basis tone frequency in each phase.
    Results: The fission boundary (FB) threshold was obtained in 500-2000 Hz. FB threshold was better in low frequencies than high frequencies. FB thresholds were independent of frequency when expressed as equivalent rectangular bandwidth (ERB).
    Conclusion: Fission boundary threshold increased with the increase of frequency. When we used ERB, FB threshold was independent of frequency.

  • XML | PDF | downloads: 260 | views: 398 | pages: 140-144

    Background and Aim: Tinnitus is a distressing symptom for which few treatments exist. Low-frequency repetitive transcranial magnetic stimulation (rTMS) of the temporal cortex has been proposed as a treatment for chronic tinnitus. This study determined relationship between psychoacoustic parameters such as loudness and frequency of tinnitus and outcome with rTMS treatment.
    Methods: Twenty six patients (22 male, 4 female) with chronic tinnitus received low frequency (1 Hz) rTMS at intensity 110% motor thre­shold and 1200 stimuli on three subsequent days to the left auditory cortex. The treatment out­come was assessed with loudness balance test and Tinnitus Handicap Inventory (THI).
    Results: There was a significant difference between loudness of tinnitus and THI scores before and after rTMS. There was no correlation between psychoacoustic parameters loudness and frequency of tinnitus and rTMS treatment outcome.
    Conclusion: Our data suggest that repetitive transcranial magnetic stimulation, regardless of loudness and frequency of tinnitus, can be used as a therapeutical tool for the treatment of tinnitus.

  • XML | PDF | downloads: 285 | views: 838 | pages: 145-152

    Background and Aim: Although recent research has revealed the positive effects of bilin­gualism on children's cognitive abilities, little information is available on the relationship bet­ween bilingualism and working memory. Working memory is generally composed of four dis­tinct parts, among which the phonological loop plays an important role in speech and language development, reading skills, and learning. In the present study, bilingual and monolingual stude­nts were compared in terms of auditory-verbal memory performance, using Rey auditory-verbal learning test.
    Methods: In this cross-sectional study, the auditory-verbal memory performance of 56 monolingual and 55 bilingual students were assessed, using the Persian version of Rey auditory-verbal learning test. The study samples were selected among students in the fifth and sixth grades of primary school. Finally, the scores obtained on the test were compared between the two groups.
    Results: The mean scores of stages 1-5, 7, and 8 of Rey test were 48.71 (SD=6.71) out of 75, 10.25 (SD=2.29) out of 15, and 10.50 (SD=2.27) out of 15 in monolinguals and 53.54 (SD=5.24), 11.80 (SD=2.13), and 11.98 (SD=1.88) in bilinguals, respectively. There was a statistically significant difference between the scores of the two groups (p<0.001, p=0.001, and p=0.001, respectively).
    Conclusion: In the present study, the bilingual group showed a significantly better auditory-verbal memory performance, compared to their monolingual peers, based on the Rey auditory-verbal learning test. Therefore, it can be concluded that bilingualism may have a positive impact on auditory-verbal working memory.

  • XML | PDF | downloads: 262 | views: 429 | pages: 153-158

    Background and Aim: Tinnitus is perception of sound in absence of external source. Reaction time is the time between sensory stimuli and a behavior. Alternation of auditory reaction time has been shown in the literature in patients with tinnitus. This study has investigated the auditory reaction time in quiet and noise to different frequencies.
    Methods: Fifteen subjects with chronic tinnitus participated in this study. Basic auditory test and tinnitus evaluations were carried out. In order to measure auditory reaction time, the participants were instructed to press a button after hearing the target sound. Xnote Stopwatch software measured reaction times and data were collected.
    Results: Auditory reaction time to the tinnitus frequency stimulus decreases significantly (p<0.05) in tinnitus subjects in both quiet and noise conditions. This alternation is significantly different in noise compared to the quiet condition (p<0.05).
    Conclusion: Based on the results, noise can reduce auditory reaction time significantly. Also, alternation of auditory reaction time to the tinnitus frequency –especially in noise –ould suggest different central processing of the tinnitus frequency in tinnitus subjects. 

  • XML | PDF | downloads: 229 | views: 413 | pages: 159-165

    Background and Aim: Dichotic listening tests have been used to study right ear advantage (REA). Fused dichotic rhymed word test (FDRWT), using rhymed words, is advantage­ous because of reducing the effect of attention on the test results. Development of Persian version of the FDRWT, and evaluation of its psychometric properties in normal children were the aims of the present study.
    Methods: This study was conducted in two parts: selecting Persian monosyllabic word pairs according to the intended criteria and assessing content validity through Lawshe method. The test was set in a dichotic condition using four lists. Each list contains 30 pairs of words which were administered on 204 normal right-handed children from six different age groups (6-11 years old) of both genders. In order to evaluate the reliability of the test, retest was carried out within one to three weeks after the initial test.
    Results: Content validity index (CVI) of FDRWT was 0.89. The results indicated greater right ear average scores for all the age groups (p<0.001). The average ear advantage for the age groups ≤ 10 years old was significantly higher than that of 11 year-old age group. The test has excellent internal consis­tency and high reliability (p<0.001).
    Conclusion: The findings showed desirable validity and reliability of Persian version of the FDRWT so it can be used in evaluation of hemispheric language specialization in Persian-speaking children. More studies are needed to examine the test results in children suspected of having central auditory processing deficits.

  • XML | PDF | downloads: 601 | views: 521 | pages: 166-174

    Background and Aim: Vestibular migraine is a type of migraine that causes vertigo, dizziness, and imbalance in addition to typical migraine symptoms. In this study, we aimed to investigate vestibular system in these patients by videonystagmography (VNG), electrocochleography (ECochG), and vestibular evoked myogenic potential (VEMP) testing.
    Methods: This empirical study was conducted on 10 patients aged 18-45 years old (mean age: 29.7 years) with vestibular migraine and 10 normal subjects (mean age: 30.9 years). Immittance, audiometry, VNG, ECochG, and VEMP tests were performed in attack-free phase in both groups.
    Results: Mean value of spontaneous nystagmus was significantly higher in patients compared to the normal subjects (p<0.05). There was no statistically significant difference in oculomotor, positional, caloric, and ECochG test results between the two groups (p>0.05). In positional test, pathologic nystagmus was detected in four patients with vestibular migraine, but there was not any significant difference between the two groups in this regard (p>0.05). Mean p13-n23 amplitude was significantly lower and mean p13 latency was significantly higher in the vestibular migraine patients than that of the control group.
    Conclusion: Vestibular malfunction was more prevalent in patients with migraine than the con­trol group even between attacks. This malfunction can be observed in both peripheral and central systems. Due to heterogeneity of vestibular disorders in patients with vestibular migraine and the variety of pathologic mechanisms that affect its occurrence and progression, conducting one test alone cannot be helpful in diagnosis; thus, test battery approach is crucial.

  • XML | PDF | downloads: 276 | views: 381 | pages: 175-182

    Background and Aim: Academic achievement, especially in hard-of-hearing students, is hinged on their writing skills, and writing skill deficiency can adversely affect their cross-disciplinary skills. The purpose of this study was to explore and delineate the writing skill curriculum for hearing-impaired students in primary school system of Iran and to develop an exploratory model.
    Methods: In the exploratory research, based on grounded theory, semi-structured interviews were conducted with 39 active members in the field of hearing loss with experience of working in special schools. The themes and sub-themes of the writing skill curriculum and the associa­tions between them were explored within three steps of open, axial, and selective coding. In order to generalize the results of the qualitative phase and validate the resulting model, a ques­tionnaire was designed and completed by 231 teachers of hearing-impaired students in special schools.
    Results: The analysis process in the qualitative phase included eight themes of attention to achi­eving an optimal situation, content determination, teacher’s actions, individual differences, organizational factors, time of teaching, place, and positive consequences. In the quantitative phase, the hypotheses derived from the qualitative analysis were confirmed.
    Conclusion: For hearing-impaired students who lack sufficient language skill, the mainstay of writing skill curriculum should be considering all aspects and factors affecting the improvement of this skill.

  • XML | PDF | downloads: 360 | views: 452 | pages: 183-193

    Background and Aim: Auditory processing disorder and dyslexia have been reported by many studies as having high comorbidity. The purpose of the study was to investigate the effectiveness of central auditory processing rehabilitation program on speech reception in noise and dichotic listening in dyslexic students. The research was quasi-experimental, including a pretest, posttest and a control group.
    Methods: The population involved dyslexic elementary school students, studying in a learning disorder center in Tehran. Using convenience sampling method, 30 dyslexic students with central auditory processing disorder (CAPD) were selected and put into experimental and control groups. Speech in noise (SIN) test and dichotic digits test (DDT) were conducted in the pretest for all students. Central auditory processing rehabilitation program was designed in 12 steps with different practices. The experimental group received 15 sessions of central auditory processing rehabilitation program. Speech in noise test and dichotic digits tests were conducted again in the posttest for all students.
    Results: The data analysis using repeated measures multi-variable analysis of variance indicated a significant difference among the mean scores of speech in noise and dichotic digits tests in the experimental and control groups (p˂0.05). The experimental group had gained better scores.
    Conclusion: According to the results, the central auditory processing disorder rehabilitation program significantly enhanced speech reception in noise and dichotic listening in the dyslexic students.