Auditory and Vestibular Research Journal
Year:2007 | Volume:15 | Issue:2 (26)|Papers Count:9

Background and Aim: Analysis of transient evoked otoacoustic emissions (TEOAEs) is of considerable interest due to their close relation with cochlear mechanisms which reveal cochlear function. The particular structure of TEOAEs requires a method with both a satisfactory time and frequency resolution. Among different methods the time –frequency techniques are the most suitable approaches. The aim of this study was to investigate the differences between neonate’s cochlear function and adult’s cochlear function using time –frequency approaches in TEOAEs. Materials and Method: The data of this cohort study was obtained from a sample of 23 normal neonates, aged between 1-28 days, and 31 normal adults, aged between 18 -25 years. TEOAEs with click stimulus were performed for both ears .The TEOAEs files were investigated in time – frequency transform software in off-line mode. The signal to noise ratio(SNR) and response level (dB) of TEOAEs were analysed. Results: The reproducibility, SNR and response level in neonates was greater than adults and in both groups there were no significant difference between responses of males and females and of the right and the left ears. Concolusion: There are differences between neonate’s and adult’s cochlear response. High frequencies responses are stronger in neonate’s cochlea.

Background and Aim: A common complaint of children with learning disability (LD) is difficulty in understanding speech in the presence of background noise. Evidence from animal and human studies has indicated that the medial olivocochlear bundle (MOCB) play a role in hearing in the presence of noise. The MOCB function can be evaluated by the suppression effect of the click evoked otoacoustic emission (CEOAEs) in response to contralateral white noise. The present study was conducted to compare the suppression effect of CEOAEs between LD and normal students. Materials and Method: This research is an analytic-interventional study. The study group consisted of 20 learning disabled and 20 normal male students. The suppression effect of CEOAEs was evaluated by a comparison between CEOAEs levels in two conditions- with and without presentation of contralateral white noise. Results: In the absence of noise there was no significant difference between CEOAEs amplitudes of two groups while there was significant difference between CEOAEs of two groups in the presence of noise. The suppression effect of CEOAEs in normal students had significant difference with LD students.Conclusion: The reduced suppression effect in LD students indicates the reduced activity of the MOCB function and efferent pathway in LD students which affect their ability to hear in the presence of background noise. Consequently, the suppression effect of CEOAEs can be used in the test battery approach of LD children.

Background and Aim: Learning disability (LD) is one of the most prevalent problems among elementary school children. Approximately 10 percent of all elementary school children suffer from this problem. It has been determined that learning disability is predominantly accompanied with subtle impairment in central auditory nervous system. The main idea of this study was to evaluate middle latency auditory evoked potential (MLAEPs) in learning disabled children. Materials and Method: This cross-sectional study investigated middle latency auditory evoked potential in children with learning disability (n = 31) compared to normal children (n = 31). Latencies and amplitudes of MLAEPs results with different stimulus intensity and binaural stimulation were compared between two groups. Results: Compared to control group, learning disabled children exhibited smaller amplitudes for all the components except the right ear Na and Pa. There is no significant difference between two groups for latencies of the components. Conclusion: It seems that middle latency auditory evoked potential may be useful in diagnosis and evaluation of learning disabled children although more investigation is required.

Background and Aim: Learning Language is a skill which is acquired in early childhood. So, language gradually developed and new words and new structures slowly added to language knowledge. Hearing sense is the most important acquisition for of language and hearing disorder is a barrier for natural language acquiring .The purpose of this study is comparison between morphological and syntactic features of 4 to 5 years old severe to profound hearing impaired and normal children. Materials and Method: This cross-sectional study performed on 10 normal-hearing children with mean age of 4-5, from Gazvin kindergartens and 10 hearing impaired children with similar IQ and age from Nioosha Rehabilitation Center. The language and non language information was received by spontaneous and descriptive speech, and questionnaire, respectively and for comparing syntax comprehension, Specific language impairment test was used. Then these results were compared between two groups.Results: Difference between spontaneous speech and descriptive speech in hearing impaired child is just like normal child. These differences are that the number of utterance, the mean of lexical morpheme, functional morpheme in spontaneous speech is greater than descriptive speech but the mean length of utterance and richness of vocabulary in descriptive speech is greater than spontaneous speech. Mean of lexical morpheme, functional morpheme and richness of vocabulary related to morphological part and the number of utterance, the mean length of utterance and syntax comprehension related to syntax, in spontaneous and descriptive speech of normal children speech is greater than hearing impaired.Conclusion: According to recent researches, compared with normal child, the hearing impaired child nearly never to reach equal level, and for this reason, training for this group is necessary. It is concluded that although these children have severe to profound hearing loss they are developing their language by auditory training, hearing aid, language therapy and educational assistance and they only have delay in period of language learning. In the other words, language growth of a 4-5 year old hearing impaired child is almost similar to a 3 year old normal child.

Background and Aim: The purpose of this research is to study the standardization of speaking and reading rates in a group of normal speaker of female students, and to compare them. As the rate of speech is an important variable in the evaluation and treatment of stuttering, cluttering, dysarthria and apraxia. Materials and Method: One hundred of second grade students of primary school and an equal number of fifth grade students participated in this study. All subjects were native speakers of Farsi, who passed an informal, screening test of articulation and speech. None of the subjects had a history of speech, hearing, or neurological disorders. The subjects were asked to read from the 180 words portion of their Farsi book and tell story. Their speech was recorded by using a tape recorder. Then the data were analyzed for word and syllable rate. In transcribing the samples, single morpheme was counted as single word and compound words were counted as two words if they had two free morphemes. Non-word interjections were excluded from word and syllable counts while word interjections and repeated words were included in the count. Independent t-test and paired t-test were used for analyzing. Results: In the second grade students the reading rate is, on the average, 189.4 syllable per minute (SPM)(94.9 word per minute(WPM), 3.1 syllable per second(SPS)) and the talking rate is 189.8 SPM (99.1 WPM, 3.1 SPS) and in the fifth grade student the reading rate is 223.9 SPM (119.0 WPM, 3.7SPS) and the talking rate is 210.26 SPM (109.5 WPM , 3.4 SPS). Conclusion: The result highlight that in the fifth grade students, reading rates is higher than talking rates while in the second grade they are not, because they do not have enough skills for whole word reading. A remarkable finding in this research is that, reading and talking rates in the fifth grade students are higher than the second grade students.

Background and Aim: Although for a child to maximize his or her mastery of language, hearing aids (HAs) must consistently be worn, and they must be functioning correctly many studies indicates some hearing- impaired children's hearing aid do not work perfectly. The purpose of this study was to determine types of defects in students' hearing aid (HA) in Tehran Exceptional Schools.Materials and method: In this cross-sectional analytic study defects in sixty -two HAs of 41 children were determined. All were the students of Exceptional Schools referred to Audiology Clinic, Faculty of Rehabilitation Medical Sciences University of Tehran. Functions of the HAs were first checked by a sthetoclips. Then the electro acoustic measurements performed to determine the values of maximum gain and maximum power output. The data were separately recorded in a questionnaire for each kind of the HAs.Results: Fifty-six percent of HAs functioned perfectly and forty-four percent were not. The most Frequent defects were 24% and 20% pertained to the battery and manual controls respectively. External components had more difficulties than internal components. Seventy percent of ear molds were damaged. There were significant differences between peak of FOG and MPO curves in the catalogue and electroacoustic measurements in 2cc coupler.Conclusion: Most damaged parts of HAs in Tehran Exceptional students is related to the battery and controls which are external components of HAs. Because of high rate of dysfunctioning HAs and ear molds in this population in this survey, it is necessary to promote orientation and counseling level after fitting and to develop the quality of HAs and ear molds for Exceptional School students.

Background and Aim: Self-reported and questionnaire method for hearing impairment assessment allows us to study and to detect the invisible related issues, while they can not be done by traditional audiometry procedures. The purpose of this study is to compare measurement of hearing handicap using self-reported and staff version of NHHI and hearing thresholds in nursing home residents.Materials and Method: The study participants were 43 individuals, 23 males and 20 females, aged 45-95 years. Pure tone average was calculated after conventional Pure tone audiometry. The self- and staff- reported questionnaire were also fulfilled.Results: Nine (20.9%) individuals have normal hearing, 6 (14%) have slight, 10 (23.3%) mild, 7 (16.3%) moderate, 6 (16.3%) moderate to severe, 4 (9.3%) severe, and 1 (2.3%) profound hearing loss. Mean score of self and of staff reported versions were 32.22 % 2:29.31 and 32.67% 2:30.98, respectively.According to Kruskal-wallis test, there was significant correlation between self-reported and hearing level and between staff-reported and hearing level. The Pierson coefficient variation test between self and staff-reported, and self-reported and hearing level, staff-reported and hearing level showed significant cancelation.Conclusion: The NHHI self assessment associated with other equipments significantly improved the identification and assessment of adults and elderly hearing handicap in nursing home residents.According to the study condition, it may be concluded that the self and staff version of NHHI questionnaire are significantly identical and can be used instead.

Background and Aim: Most of the studies indicates that the parents of the hearing impaired children show many mental health problems after the diagnosis of their children's hearing impairment.Counseling with the parents of the hearing impaired children is one of the most important goals of any early intervention program. This paper describes a study to determine the effectiveness of a group counseling programmed for parents of hearing impaired children.Materials and Method: It was a semi-experimental study with a single group pretest-post test design. The participants were all the parents of hearing impaired children attending in an early intervention center. First the parents' mental health were assessed. Then the group counseling program was implemented. Program has involved six weekly 1.5 hour sessions. The format of each session included both lecture presentation and group discussion using cognitive behavioral procedure. Subjects were assessed before and immediately after group therapy by means of General Health Questionnaire (GHQ) and Symptom Check List 90 (SCL-90) questionnaires.Results: The first part of the project had shown that over the half of the parents had considerable psychosocial morbidity. Comparisons showed a significant reduction from pretreatment to post treatment in depression, anxiety and most of other psychological problems. Conclusion: The study supports the effectiveness of group therapy programs in the treatment of parents of hearing impaired children. Concerning the progress of early detection programs for the children's hearing impairment more studies should be done in the field of counseling with their parents.

Background and Aim: Auditory neuropathy is an hearing disorder in which peripheral hearing is normal, but the eighth nerve and brainstem are abnormal. By clinical definition, patient with this disorder have normal OAE, but exhibit an absent or severely abnormal ABR. Auditory neuropathy was first reported in the late 1970s as different methods could identify discrepancy between absent ABR and present hearing threshold. Speech understanding difficulties are worse than can be predicted from other tests of hearing function. Auditory neuropathy may also affect vestibular function.Case Report: This article presents electrophysiological and behavioral data from a case of auditory neuropathy in a child with normal hearing after bilirubinemia in a 5 years follow-up. Audio logical findings demonstrate remarkable changes after multidisciplinary rehabilitation.Conclusion: auditory neuropathy may involve damage to the inner hair cells-specialized sensory cells in the inner ear that transmit information about sound through the nervous system to the brain. Other causes may include faulty connections between the inner hair cells and the nerve leading from the inner ear to the brain or damage to the nerve itself. People with auditory neuropathy have OAEs response but absent ABR and hearing loss threshold that can be permanent, get worse or get better.