Auditory and Vestibular Research
Volume:22 Issue: 4, 2013

Omega-3 fatty acid have structural and biological roles in the body ''s various systems. Numerous studies have tried to research about it. Auditory system is affected a s well. The aim of this article was to review the researches about the effect of omega-3 on auditory system. We searched Medline، Google Scholar، PubMed، Cochrane Library and SID search engines with the «auditory» and «omega-3» keywords and read textbooks about this subject between 19 70 and 20 13. Both excess and deficient amounts of dietary omega-3 fatty acid can cause harmful effects on fetal and infant growth and development of brain and central nervous system esspesially auditory system. It is important to determine the adequate dosage of omega-3.

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. 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. 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. 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.

The auditory steady state response is a modern test for estimating hearing thresholds، especially in difficult to test individuals. However، there are few bone conduction auditory steady state response data، particularly for individuals with hearing loss. The objective of this study was to investigate bone conduction auditory steady state response thresholds in individuals with sensorineural hearing loss and normal hearing. In a cross-sectional study، 10 individuals with normal hearing and 10 with sensorineural hearing loss at the age of 15-30 years were selected by non-probability sampling. Auditory steady state response and pure tone audiometry to bone conduction stimuli in 500 and 2000 Hz were recorded in two groups. Paired and independent t-test were used to compare data between the groups. There was low correlation between bone conduction auditory steady state response and pure tone audiometry in both groups (p>0. 05 for both). The difference of behavioral thresholds and auditory steady state response in 500 Hz was higher than 2000 Hz in both groups (p=0. 033 for normal hearing and p=0. 017 for sensorineural hearing loss groups). Comparison of these results showed significant differences between the two groups (p<0. 001). In both groups، there was low correlation between bone conduction auditory steady state response and pure tone audiometry thresholds. In individuals with sensorineural hearing loss and in higher frequencies، bone conduction auditory steady state response thresholds was closer to pure tone audiometery thresholds.

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. 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. 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). 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.

Nasalization of a vowel refers to the addition of nasal resonance to the vocal tract transfer function. Also، vowel nasalization occurs because of coarticulation. Coupling of the nasal resonating space to the oropharyngeal cavity alters the vocal tract formants in complex ways. The purpose of this study was to investigate the effect of nasalization on /a/ vowel formants in before and after nasal consonant. In current cross-sectional study، voice samples of 60 normal children ranging the age of four-nine years were investigated. Participants were asked to repeat / ʔ ama/ three times and vowel /a/ after presentation of an auditory model. Then، obtained samples were analyzed using Praat 5. 3. 13. Average of F0، F1، F2 and F3 were calculated for /a/ comes before and after /m/ in production of / ʔ ama/ over three trials. There were statistically significant differences of F1، F2 and F3 between / a/ which proceeds nasal consonant and /a/ follows nasal consonant، the before nasal consonant /a/ versus single /a/ and the after nasal consonant /a/ versus single /a/ (p=0. 001 for all). F1، F2 and F3 in /a/ before nasal consonant affected by anticipatory nasal coarticulation and in /a/ after nasal consonant affected by carry-over nasal coarticulation. This study showed nasal coarticulation and nasalization result in decreasing F1، F2 and F3 in /a/ vowel.

Backgrand and The measurement of speech intelligibility refer to determining the measure of speech intelligibility in communication. The speech intelligibility is used for decision-making in intervention، the determination of intervention goals، and the measurement of intervention outcomes. This study aimed to investigate the speech intelligibility among the children aged 36 to 60 months. In this cross-sectional study، 360 healthy children (180 girls and 180 boys) were chosen among children of kindergardens in Khorramabad city، Iran. Speech sample of subjects was collected by calling pictures of Hydari et al 2010، speech intelligibility measurement test (2010). The voices of the subjects were tape-recorded and speech intelligibility of children was studied within 12 age-groups arranged by two months. The minimum speech intelligibility was concerned to 36 and 37 months old and the maximum was concerned to 58 and 59 months old. There was a significant differences among age-group 36 and 37 months old with 44 and 45 months old and above، age-group 38 and 39 months old with 55 and 54 months old and above، and age-group 40 and 41 months old with 58 and 59 months old (p<0. 05 for all). There was no significant difference among other age groups. There was no significant difference between boys and girls. Speech intelligibility has the highest growth during the age of 36 to 46 months and it had lowest growth during the age of 46 months and elder range.

Dyslexia is the most common learning disability. One of the main factors have role in this disability is auditory perception imperfection that cause a lot of problems in education. We aimed to study the effect of auditory perception training on reading performance of female students with dyslexia at the third grade of elementary school. Thirty-eight female students at the third grade of elementary schools of Khomeinishahr City، Iran، were selected by multistage cluster random sampling of them، 20 students which were diagnosed dyslexic by Reading test and Wechsler test، devided randomly to two equal groups of experimental and control. For experimental group، during ten 45-minute sessions، auditory perception training were conducted، but no intervention was done for control group. An participants were re-assessed by Reading test after the intervention (pre- and post- test method). Data were analyed by covariance test. The effect of auditory perception training on reading performance (81%) was significant (p<0. 0001) for all subtests execpt the separate compound word test. Findings of our study confirm the hypothesis that auditory perception training effects on students'' functional reading. So، auditory perception training seems to be necessary for the students with dyslexia.

American Academy of Pediatrics (AAP) established standards for neonatal hearing screening programs in 1999. The main purpose of this study was to achieve exact statistical data of this program in Ahvaz، Iran، and to compare these results with the standards of American Academy of Pediatrics. In this cross-sectional descriptive study، the data of neonatal hearing program in Ahvaz west health center from 2008 to 2011 were reviewed. Data were analysed by descriptive statistics. From 25073 neonates، 25 had hearing loss. The false positive and referral ratio to the diagnosis stage were 2. 6 and 0. 48 percent، respectively. 92 percent of hard of hearing infants were diagnosed before three months of life. In comparison with the standards of American Academy of Pediatrics، all of the items، except two، were included completely or relatively complete. But، more efforts must be done to achieve the whole standards which are available.

Cerebrovascular accident is a neurological disorder involves central nervous system. Studies have shown that it affects the outputs of behavioral auditory tests such as dichotic auditory verbal memory test. The purpose of this study was to compare this memory test results between patients with cerebrovascular accident and normal subjects. This cross-sectional study was conducted on 20 patients with cerebrovascular accident aged 50-70 years and 20 controls matched for age and gender in Emam Khomeini Hospital، Tehran، Iran. Dichotic auditory verbal memory test was performed on each subject. The mean score in the two groups was significantly different (p<0. 0001). The results indicated that the right-ear score was significantly greater than the left-ear score in normal subjects (p<0. 0001) and in patients with right hemisphere lesion (p<0. 0001). The right-ear and left-ear scores were not significantly different in patients with left hemisphere lesion (p=0. 0860). Among other methods، Dichotic auditory verbal memory test is a beneficial test in assessing the central auditory nervous system of patients with cerebrovascular accident. It seems that it is sensitive to the damages occur following temporal lobe strokes.

Rapid automized naming test is an appropriate tool to diagnose learning disability even before teaching reading. This study aimed to detect the cut-off point of this test for good readers and dyslexics. The test has 4 parts including: objects، colors، numbers and letters. 5 items are repeated on cards randomly for 10 times. Children were asked to name items rapidly. We studied 18 dyslexic students and 18 age-matched good readers between 7 and 8 years of age at second and third grades of elementary school; they were recruited by non-randomize sampling into 2 groups: children with developmental dyslexia from learning disabilities centers with mean age of 100 months، and normal children with mean age of 107 months from general schools in Tehran. Good readers selected from the same class of dyslexics. The area under the receiver operating characteristic curve was 0. 849 for letter naming، 0. 892 for color naming، 0. 971 for number naming، 0. 887 for picture naming، and 0. 965 totally. The overall sensitivity and specificity was 1 and was 0. 79، respectively. The highest sensitivity and specificity were related to number naming (1 and 0. 90، respectively). Findings showed that the rapid automized naming test could diagnose good readers from dyslexics appropriately.

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. 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. 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. 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.

Subjective tinnitus etiology has not been fully understood. Recently، in normal hearing subject one of the tinnitus theories، more specifically the medial olivocochlear tract، is related to the dysfunction of the efferent auditory system. The aim of this study was to determine the potential contribution of a defective cochlear efferent innervations to the chronic tinnitus in patients with normal hearing and determine the relation between tinnitus loudness and the amount of suppression of the transient evoked otoacoustic emission. This study was conducted on 20 tinnitus patients aged between 20-45 years and 20 controls matched for age and gender in School of Rehabilitation، Tehran University of Medical Sciences. Transient otoacoustic emission testing without and with contralateral white noise at 55 and 65 dB was performed on each subject. The amplitudes of the emissions in the two groups was significantly different (p=0. 001)، but no correlation between tinnitus loudness and the amplitudes of the emissions in the presence (p=0. 3) and absence (p=0. 06) of contralateral noise. The suppression of the transient evoked otoacoustic emission by contralateral white noise did not reach statistically significant levels in tinnitus patients while the amplitude in control group reduced significantly.