Auditory and Vestibular Research Journal
Year:2005 | Volume:14 | Issue:23|Papers Count:9

Objective: Comparison of Air conduction (AC) and Bone conduction (BC) auditory brain stem response (ABR) latencies. Materials and Methods: In this cross-sectional study, 34 (17 males, 17 females) normal-hearing young subjects tested with AC- and BC-ABR. Wave V latencies of both procedures were compared Results: BC- wave V latency significantly prolonged about 0.5 ms. that prolongation was less with decreasing intensity.  Females' AC-and BC - ABR latencies were less than males'. Conclusion: AC- and BC- ABR appeared to be useful to determine sensory-neural acuity in children with atresia or difficult to test subjects specially newborns.

Objective: Noise measurement and frequency analysis of commercially available noisy toys were the main purposes of the study. Materials and Methods: 181 noisy toys commonly found in toy stores in different zones of Tehran were selected and categorized into 10 groups. Noise measurement was done at 2, 25, and 50 cm from toys in dBA. The noisiest toy of each group was frequency analyzed in octave bands. Results: The highest and the lowest intensity levels belonged to the gun (mean=112 dBA and range of 100-127 dBA) and to the rattle-box (mean=84 dBA and range of 74-95 dBA), respectively. Noise intensity levels significantly decreased with increasing distance except for two toys. Noise frequency analysis indicated energy in effective hearing frequencies. Most of the toys energies were in the middle and high frequency region. Conclusion: As intensity level of the toys is considerable, mostly more than 90 dBA, and also their energy exist in the middle and high frequency region, toys should be considered as a cause of the hearing impairment.

Objective: This research is designed to study palatographic specification of lingual- palatal consonants in Persian language. Since there is not any research about the lingua-palatal contacts in Persian language, this research is designed to determine these "normal" contact patterns and variability of Persian consonant production. Materials and Methods: In this study 16 consonants have been studied. Subjects were 4 normal adults. Each person repeated every consonant ID times in (CVCV) syllable with vowel /a/. Frame of maximum contact for each consonant was determined. Individual and overall representative frames obtained from those frames. Results: There are different patterns of variability between Persian consonants. Consonants /n/, /f/, and /I/ display more variable articulation and stops and affricates display less variable articulation than others. Conclusion: Persian consonants have different contact patterns. These findings are in accordance with previous studies in other languages.

Objective: determining difference limen for Frequency (DLF) in string musicians. Materials &Methods: This case-control study was conducted on 15string musicians with musicianship> 10 years (30 ears) and 15 normal hearing subjects (30 ears). They all were male and 20-30 years old. DLF was measured after otoscopy and immitance audiometry and pure tone audiometry. Results: DLF was significantly different between two groups of case and control. DLF in musicians is less than the normal hearing subjects. Conclusion: It seems that familiarization with notes results in better DLF in musicians comparing to others.

Objective: To determine phonological processing in elementary children with Down syndrome. Materials and Methods: Phonetic test is used to extract phonological processing in 40 children with Down syndrome. They were normal in hearing and oral structure. Results: There was significant difference between girls and boys in some subgroups of phonological processing. In assimilation, voiceless assimilation in boys and complete assimilation in girls were the most. Nasal assimilation in girls and fricative assimilation in boys were the least. In substitution, the least mean belonged to liquid and nasal substitution in girls and voice ness substitution in boys. In general there was no significant difference between age and phonological awareness; however, there was direct correlation between syllable structure and age and reverse correlation between age and stop assimilation. Conclusion: In addition to 3 groups of phonological processing including: syllable structure, assimilation, and substitution, omission was seen. The difference between girls and boys indicates they are impressed by the phonetic structure of words in different ways. Correlation between age and phonological processing shows phonological errors may be resulted from deviation.

Objective: Obtaining the diadochokinetic syllable rates standard among the elementary students in 3, 8, and 19 educational zones in Tehran. Materials and Methods: 1997 students (980 girls and 1017 boys) randomly selected and examined. Frequency of /pa/, /ta/, /ka/ and /pataka/ in 5 seconds and the number of seconds for producing /pa/, /ta/, /ka/ and /pataka/ for 15 times were recorded for every student. Results: There is significant difference between means of time and frequency with increasing age. Means of some syllable rates were significantly different between girls and boys. Conclusion: Mean of syllable frequency was increased and the mean of syllable repetition time was decreased with increasing age. On the whole, boys seem to repeat syllables faster than the girls do.

Objective: Genetic studies show that consanguineous marriage can increase the probability of incidence of genetic impairments such as hearing impairments. The target of this study is to identify the prevalence of consanguinity among the parents of hearing impaired students in primary schools. Materials and Methods: We selected all of deaf students of Tehran (614 students). Their mothers answered to questionnaires. The questions were about Risk Factors of deafness in mother pregnancy or in neonatal period. Results: from 614 students, 389 parents of them (64%) had consanguineous marriage and 223 person (36%) didn't have this factor. 2 person did not answer to this question. In this study we observed that there is 32.3% family history of hearing loss, 29.2%deaf sister and brother, 17% ear infection history. Other risk factors were studied too. Also there is significant correlation between consanguinity and more than one deaf children in the family (p<0.005). Conclusion: According to high incidence of consanguinity (64%) that was observed in this study it may be one of most important causes of sensory neural hearing loss in children, so we should give enough information about this problem to the people.

Background: Facial schwannoma is a rare tumor arising from any part of the nerve. Probable symptoms are partial or facial weakness, hearing loss, visible mass in the ear, otorrhea, loss of taste, rarely pain, and sometimes without any symptoms. Patients should undergo a complete neurotologic history, examination with documentation of facial and auditory function, specially C.T. scan or M.R.I. Surgery is the only treatment option although the decision of when to remove facial schwannoma in the presence of normal facial function is difficult. Case: A 19-year-old girl with all above symptoms in the right side except loss of taste is diagnosed having facial schwannoma with full examination, audiometric, and radiological tests. She underwent surgery. In follow-up facial function were mostly restored. Conclusion: The need for careful assessment of patients with Bell's palsy cannot be veremphasized. In spite of the negative results if still there is any suspicion, total facial nerve exploration is necessary.