Auditory and Vestibular Research Journal
Year:2009 | Volume:17 | Issue:2 (30)|Papers Count:12

Background and Aim: In neural response telemetry (NRT), intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential (ECAP), is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential's threshold changes in three monthes after receiving the devise in pediatric cochlear implant recipients.Materials and Methods: This longitudinal study evaluated the potential's threshold in four given electrodes in four sessions after receiving the device by approximately one months intervals in children implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December.Results: ECAP mean threshold level of each electrode did not significantly change in different sessions, while there was significant difference between apical and basal electrodes’ responses in every session (p<0.001).Conclusion: The reliabiliy of the responses result in more certainty of clinician to fit the speech processor for a long time. Better responses in apical electrodes may lead to develope an effective coding strategy.

Background and Aim: Tinnitus is an unpleasant sound which can cause some behavioral disorders. According to evidence the origin of tinnitus is not only in peripheral but also in central auditory system. So evaluation of central auditory system function is necessary. In this study Auditory brainstem responses (ABR) were compared in noise induced tinnitus and non - tinnitus control subjects.Materials and Methods: This cross - sectional, descriptive and analytic study is conducted in 60 cases in two groups including of 30 noise induced tinnitus and 30 non-tinnitus control subjects. ABRs were recorded ipsilateraly and contralateraly and their latencies and amplitudes were analyzed.Results: Mean interpeak latencies of III-V (p= 0.022), I-V (p=0.033) in ipsilatral electrode array and mean absolute latencies of IV (p=0.015) and V (p=0.048) in contralatral electrode array were significantly increased in noise induced tinnitus group relative to control group.Conclusion: It can be concluded from that there are some decrease in neural transmission time in brainstem and there are some sign of involvement of medial nuclei in olivery complex in addition to lateral lemniscus.

Background and Aim: One of the most common complaints, particularly among patients with normal or near normal low-frequency hearing, is that their voice sounds "hollow". This is associated with "Occlusion effect". The aim of this study was to comparison of occlusion effect in normal hearing subjects via Real Ear Measurement and Audiometric Bing test.Materials and Method: Twenty volunteers with normal hearing (10 male, 10 female), with ages ranging from 18 – 24 years were enrolled in this study. First, audiometric Bing test was performed in frequencies of 250, 500, 750 and 1000 Hz. Then in real ear measurement, subjects were instructed to vocalize /â/ and /i/ for 5 seconds. Probe microphone was recorded the sound pressure in the ear canals. The degrees of occlusion effect unit were obtained for further analysis.Results: The means of occlusion effect were present in all subjects. There was no correlation between the results of audiometric Bing test and real - ear measurement. No significant difference was obtained between genders and monaural or binaural occlusion in real-ear measurement. But in audiometric Bing test, the difference between monaural or binaural occlusion was significant (p<0.05).Conclusion: The peak of occlusion effect varies significantly among hearing aid users, so the hearing aid must be tuned. Probe - microphone measures will assist in determination how much gain is enough, and where frequency - specific adjustments are needed.

Background and Aim: For better using of electropalatography in assessment and treatment procedures it is important to know normal tongue to palate contact patterns. Several factors can change consonant’s articulatory patterns. One of them is voicing. In addition to determine amount of special indices of studied consonants, this research aimed to study tongue behavior related to change in voicing.Materials and Methods: This is a descriptive analytic study. Consonant linguapalatal contacts were studied using reading electropalatography by recording 4 normal Persian speaking adults (aged between 21-25) repeating CVCV syllables (C=/s,z,t,d/, V=/a/) ten times. Contact patterns were examined for total number of electrodes contacted and other spatial indices. Comparisons were made across voicing contrast.Results: In this study amount of spacial indices of studied consonants determined. It’s found that there was not significant difference between voiced and voiceless cognate according to number of contact and other special indices.Conclusion: The findings of this study are in according with previous studies in other languages about the effect of voicing upon linguapalatal contact patterns. Difference in voicing does not make clear change in spacial indices related to tongue contact pattern. Compared to other parts, Tip of the tongue seem to be more sensitive for change in voicing and oral air pressure.

Background and Aim: Tinnitus is a common symptom among lots of people but little is known about its origins. This study was aimed at comparing the Auditory Steady - State Response (ASSR) thresholds in normal cases and patients with subjective idiopathic tinnitus (SIT) in order to diagnose its real origins.Materials and Methods: This case - control study was conducted on 19 patients with tinnitus and 24 normal cases aged 18-40 yr.The patients underwent broad medical tests to roll out any background reason for their tinnitus. ASSR thresholds were estimated in both groups at 20 and 40 amplitude modulation. The patients were selected from tinnitus patients in Research Center in Hazrat Rasoul Hospital, Tehran, Iran.Results: The mean ASSR thresholds at 40HZ modulation were worse in tinnitus patients compared to normal ones (p<0.05) but no significant statistical differences was detected at 20HZ. These results were found in both situations in which we averaged both ears thresholds and when we estimated the thresholds of the ears separately.Conclusion: It seems that the origin of the responses of the modulation of 40Hz, primary auditory cortex, midbrain regions and subcortical areas, in these patients is involved or the origin of their tinnitus is related to some kind of problems in these areas, although more investigation is needed about 20Hz.

Background and Aim: Nowadays, auditory perception is not a complete method to assess vowels quality and we need to use more objective instruments. In this study we want to determine and compare the persian vowels formants in normal and hearing Impaired students in 7-9 year old children of Isfahan.Materials and Methods: This cross sectional study was performed on 64 normal and hearing impaired students. Background information was by interview and then, vowel production test was performed. First three formants of each vowel were obtained and recorded by speech studio soft ware and Dr. Speech device Data were compared between groups.Results: Mean F1 and F2, and F2/F1 and F3/F1 ratio of Persian vowels between these three studied groups were different significantly. Mean F3 of /o/, /e/ and /a/ in all groups was different significantly. Although we could not find such a significant differences for /u/, /i/ and /ᴂ/ between these groups (p<0.05).Conclusion: The most important difference between normal and hearing impaired children is their vowel Space and we found that, the more sever the hearing impairment is, the closer vowel space will be seen. The hearing impaired children rely mostly on their proprioceptive sense because of their hearing deficiency and it causes less movement of the tongue, so they usually substitute vowels which have similar F1 and F2.

Background and aim: Reading is one of the most essential skills in this century. Reading disorders can cause several problems for the person who has reading disorder. Early assessment and diagnosis play an important role in treatment of this disorder. The main purpose of this study was to develope a screening inventory reading test (IRT) for first to fifth grade student in Isfahan in order to early diagnosis of reading disorder.Materials and Methods: The test, consisting of 100 words context and four comprehension questions, named Inventory Reading Test (IRT), was evaluated by several speech therapists. It was standardized by testing on one thousand boys and girls, 200 students in every grade, that were selected through a multi - stage random sampling method. Test was performed on two other groups, a normal and a reading - disordered.Results: Scores of reading accuracy and velocity were highly correlated with the test total score. Test reliability was calculated as 0.77 by Cronbach`s alpha measure. There was significant difference between two groups mean score (p=0.01).Conclusion: IRT seems to be an appropriate tool for screening reading disorder of first to fifth grade students.

Background: Fanconi anemia (FA) is an autosomal recessive genetic disorder wich characterized by progressive pancytopenia, multiple congenital anomalies, increased susceptibility to acute myelogenous leukemia and epithelial cancers specially in head and neck and GUT. Characteristic feature of FA include short stature, café-au - laitspots, small eyes, mental retardation, skeletal and ear anomaliesCase: A 23 - year - old man who was a known case of FA since he was ten reffered to audiology clinic because of severe hearing loss. His initial diagnosis was pneumonia. Audilogic evaluation revealed bilateral profound hearing loss.Conclusion: One of the anomalies in FA are ear anomalies. These included conductive haering loss, external auditory canal stenosis and auricular malformation and progressive sensoryneural hearing loss. In this report external auditory canal and tympanic membrane were normal. The result of tympanometry were type An and audiometry were bilateral profound hearing loss that is a rare finding in FA patient.