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 10 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/, /ſ/, and /l/ 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: 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&apos AC-and BC - ABR latencies were less than males&apos.
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.

Background and Aim: Hearing sensitivity is so vital for musicians as loud music can cause hearing loss. The aim of this study was to assess hearing sensitivity of musicians in order to determine the effects of music exposure on hearing organ.
Materials and Methods: This case-control study  was conducted on 15 string musicians with musicianship history of more than 10 years and 15 normal hearing subjects. They all were male and 20-30 years old. TEOAEs and DPOAEs performed after otoscopy , immittance and pure tone audiometry in octave frequencies between 250 to 16000 Hz.
Results: There is not significant difference between pure tone thresholds of two groups for all frequencies.A significant difference of TEOAE is found between two groups for total response and amplituds of TEOAEs . DPOAEs amplituds are not significantly different between two groups .
Conclusion: Musicianship may  affect TEOAEs amplitudes , but cannot affect results of PTA and DPOAEs. Therefore this can be useful to detect cochlear lesions secondary to music exposure and also as a tool in hearing protection program.

Background and Aim: Hyperbilirubinemia is one of the most common abnormalities during the neonatal period. Approximately 60% full-term and 80% preterm neonates suffer from hyperbilirubinemia. Hearing loss is one of the most prevalent side-effects of hyperbilirubinemia. This happens when the serum concentration of indirect bilirubin increases dramatically. The main purpose of this study is to evaluate the hearing status and to diagnose the probable site of lesion in affected children.
Materiads and Methods: In this cross-sectional study, 33 newborn to two year old subjects uffering from hyperbilirubinemia were evaluated using auditory brainstem response (ABR) and transient evoked otoacoustic emissions (TEOAE) tests In the Audiology department of the Faculty of Rehabilitation Sciences Iran University of Medical Sciences sampling method was accessible.
Results: 21% of the subjects had severe to profound hearing loss and 9% of subjects had mild to moderate hearing loss. In 51% of the subjects there was no response to ABR and TEOAE tests indicating cochlear and/or retrocochlear lesion. The other 15% manifest only abnormal ABR test indicating the presence of the auditory neuropathy.
Conclusion: TEOAEs test has its own limitations in these subjects, that is the hearing status of such patients can not be completely evaluated by using just TEOAE test. Therefore, to detect hearing loss both ABR and TEOAE tests must be performed in these subjects.

Background and Aim: One of the most significant complaints of children with learning disability (LD) is difficulty in understanding speech in the presence of background noise. Different studies have shown that the medial olivocochlear bundle(MOCB) may play a role in hearing in noise. The MOCB function can be evaluated by the contralateral suppression of tone burst evoked otoacoustic emissions (TBEOAEs).The aim of the present study was to evaluate frequency specifications of MOCB by the contralateral suppression of TBEOAEs at 1,2,3 and 4 KHz in response to contralateral white noise in LD students.
Materials and Methods: This case-control study was conducted on 34 LD students aged 7-11 years and 31 normal students matched for age.The contralateral suppression of TBEOAEs was evaluated by comparing TBEOAEs amplitudes with and without contralateral white noise.
Results: In the absence of noise there was no significant difference between TBEOAEs amplitudes of two groups. In the presence of noise significant decrease was seen in TBEOAEs amplitudes at 1,2,3 and 4 KHz in both groups. In LD students the amount of this decrement at 1,2 and 4 KHz was lower than in the normal students.
Conclusion: A significant diminished suppression effect at 1,2 and 4 KHz in LD students indicates that at these frequency regions MOCB function was reduced. Therefore its suggested that the assessment of MOCB by evaluating the suppression effect of TBEOAEs included in the test battery approach used in the diagnostic of LD students.

Background and Aim: Lack of early detection of and intervention for infants hearing loss results in a significant delay in speech and language development. So auditory rehabilitation plays an important role in improving the diminished communication ability. One of the most successful auditory training approaches is the SKI-HI parent-infant program. The purpose of this study was preparation and evaluation of Farsi-Language SKI-HI program for under 3-year-old hearing impaired  children.
Materials and Methods: After translation and modification of the text of the program, fifteen under 3-year-old children with bilateral severe sensory hearing loss who were fitted with appropriate behind the ear hearing aids received intervention for 6 months. The levels of the auditory skills were measured pre and post intervention. Intervention Efficiency Index (IEI), Pretest Developmental Rate (PDR) and Proportional Change Index (PCI) were computed.
Results: The data indicated that there was a significant difference between means of IEI and PDR which were 0.87 and 0.31, respectively. PCI was 3.38 indicated that the children&aposs auditory skills developed at about 2.38 times higher rate after SKI-HI intervention than they did before.  PCI confidence interval showed that development in  the population is 1.46 to 3.30 times higher after SKI-HI intervention (with 95% probability) the rate of auditory skills.
Conclusion: The auditory training with Farsi-language SKI-HI Parent-Infant program may efficiently affect development of auditory skills of hearing impaired children.

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: Physiologic measures of cochlear and auditory nerve function may be of assistance in distinguishing between hearing disorders due primarily to auditory nerve impairment from those due primarily to cochlear hair cells dysfunction. The goal of present study was to measure of cochlear responses (otoacoustic emissions and cochlear microphonics) and auditory brainstem response in some adults with auditory neuropathy/ dys-synchrony and subjects with normal hearing.
Materials and Methods: Patients were 16 adults (32 ears) in age range of 14-30 years with auditory neuropathy/ dys-synchrony and 16 individuals in age range of 16-30 years from both sexes. The results of transient otoacoustic emissions, cochlear microphonics and auditory brainstem response measures were compared in both groups and the effects of age, sex, ear and degree of hearing loss were studied.
Results: The pure-tone average was 48.1 dB HL in auditory neuropathy/dys-synchrony group and the frequency of low tone loss and flat audiograms were higher among other audiogram&aposs shapes. Transient otoacoustic emissions were shown in all auditory neuropathy/dys-synchrony people except two cases and its average was near in both studied groups. The latency and amplitude of the biggest reversed cochlear microphonics response were higher in auditory neuropathy/dys-synchrony patients than control people significantly. The correlation between cochlear microphonics amplitude and degree of hearing loss was not significant, and age had significant effect in some cochlear microphonics measures. Auditory brainstem response had no response in auditory neuropathy/dys-synchrony patients even with low stimuli rates.
Conclusion: In adults with speech understanding worsen than predicted from the degree of hearing loss that suspect to auditory neuropathy/ dys-synchrony, the frequency of low tone loss and flat audiograms are higher. Usually auditory brainstem response is absent in this patients and use of both otoacoustic emissions and cochlear microphonics responses to measure cochlear hair cells function are suggested in them.

Background and Aim: Matching a mother wavelet to class of signals can be of interest in signal analysis and denoising based on wavelet multiresolution analysis and decomposition. As transient evoked otoacoustic emissions (TEOAES) are contaminated with noise, the aim of this work was to provide a quantitative approach to the problem of matching a mother wavelet to TEOAE signals by using tuning curves and to use it for analysis and denoising TEOAE signals. Approximated mother wavelet for TEOAE signals was calculated using an algorithm for designing wavelet to match a specified signal.
Materials and Methods: In this paper a tuning curve has used as a template for designing a mother wavelet that has maximum matching to the tuning curve. The mother wavelet matching was performed on tuning curves spectrum magnitude and phase independent of one another. The scaling function was calculated from the matched mother wavelet and by using these functions, lowpass and highpass filters were designed for a filter bank and otoacoustic emissions signal analysis and synthesis. After signal analyzing, denoising was performed by time windowing the signal time-frequency component.
Results: Aanalysis indicated more signal reconstruction improvement in comparison with coiflets mother wavelet and by using the purposed denoising algorithm it is possible to enhance signal to noise ratio up to dB.
Conclusion: The wavelet generated from this algorithm was remarkably similar to the biorthogonal wavelets. Therefore, by matching a biorthogonal wavelet to the tuning curve and using wavelet packet analysis, a high resolution time-frequency analysis for the otoacoustic emission signals is possible.

Background and Aim: Due to its ability in bonding with hard and soft tissue, healing and repairing of the bone, and proper replacing of the ossicles in middle ear, bioactive glass has come into consideration. The aim of this work was preparation, development and characterization of nanopowder bioactive glass obtained by the sol-gel technique.
Materials and Methods: Bioglass powder was made by sol-gel technique and the presence of desired elements is tested by X-ray fluorescence analysis. Trans Electronic Microscopic (TEM) technique was used to evaluate the powders shape and size. The prepared bioglass powder was immersed in the simulated body fluid solution for 30 days. Fourier transform infrared (FTIR) spectroscopy was utilized to recognize and to confirm the formation of apatite layer on prepared bioglass powder. (XRD) as a structural characterization technique was used to investigate the microstructure.
Results: The glass powder size was less than 100 nanometers. The formation of apatite layer confirmed the bioactivity of the bioglass powder and tests revealed that all the films had the signs of bioactivity. It was also found that at sintering temperatures above 900 ºC, crystalline phase Ca₂SiO₄ was formed.
Conclusion: The sol-gel nanopowder bioglass can be used as a replacement for small bones such as ossicles in middle ear, and it leads to bone osteointegration and growth of the surrounding tissue.

Background and Aim: Internal Evaluation means assessment of abilities and potentials. To promote the quality of education, research, health and finally rehabilitation is one of the most important roles and responsibilities of the universities. Promotion of quality of the theoretical and practical education for the Audiology students provides this major with its final goal that is to serve society. The purpose of this study was to evaluate the strength, weaknesses, opportunities and threats (SWOTs) of the Audiology department and to identify the ways of diminishing weaknesses and threats.
Materials and Methods: This descriptive cross-sectional study was conducted on undergraduates, postgraduates, graduates, academic staff, and the director of Audiology department in 9 areas, including management flowchart, educational programs, instructional methods and curriculum models, students, educational areas and equipments, graduate, academic staff, research, and treatment. Data were collected by questionnaires. Results were analyzed descriptively and were expressed in raw and percentage.
Results: The scores of areas in two measures were as follows: management flowchart 4.36 (87.31%), educational programs 4.17 (83.58%), instructional methods and curriculum models 4.01 (80.26%), students 3.43 (68.60%), educational areas and equipment 3.60 (72.11%), from the view of undergraduates, post graduates, faculties, graduates 3.60 (72.03%), academic staff 4.03 (80.6%), research 3.52 (70.4%), and treatment 4.54 (90.80%). The highest score was, therefore, of the treatment area and the lowest belonged to the educational area and equipments. The score of the Audiology department, as the main factor was 3.89 out of 5 which was 77.88%.
Conclusion: Audiology group total score indicates the desirable status that can be promoted to the most desirable if SWOTs are considered.

Background and Aim: Objective measurement is general and acoustic measurements in particular have become a substantial aspect of stuttering assessment during the last few decades. Measurements do not replace the perceptual judgment, but they allow a more precise diagnosis, provide more evidence for therapeutic interventions, and are useful as feedback for patients in therapy. The purpose of this investigation was to compare some adult male stutterers&apos and nonstutterers&apos acoustic features.
Materials and Methods: Adult male stutterers and nonstutterers participated this case-control  study. Their fluent reading of 20 sentences in Farsi, prolongation of  vowels /a/ and /i/, and rhythmic counting from 1 to 20 were analyed with Dr. Speech software.
Results: There were no significant differences between two groups in fundamental frequency (f₀) and standard deviation of f₀ in three speech samples (vowels /a/ and /i/, reading 20 sentences, and rhythmic counting from 1 to 20). No significant difference were between two groups for jitter and shimmer.
Conclusion: Non significant differences between two groups are somewhat due to investigation of this parameters in fluent speech of stutterers  and nonstutterers.

Background and Aim: Hyperbilirubinemia during the neonatal period is known to be an important risk factor for neonatal auditory impairment, and may reveal as a permanent brain damage, if no proper therapeutic intervention is considered. In the present study some electroacoustic and electrophysiologic tests were used to evaluate function of auditory system in a group of children with severe neonatal Jaundice.
Materials and Methods: Forty five children with mean age of 16.1 14.81 months and 17 mg/dl and higher bilirubin level were studied, and the transient evoked otoacoustic emission, acoustic reflex, auditory brainstem response and auditory steady-state response tests were performed for them.
Results: The mean score of bilirubin was 29.37± 8.95 mg/dl. It was lower than 20 mg/dl in 22.2%, between 20-30 mg/dl in 24.4% and more than 30 mg/dl in 48.0% of children. No therapeutic intervention in 26.7%, phototherapy in 44.4%, and blood exchange in 28.9% of children were reported. 48.9% hypoxia and 26.6% preterm birth history was shown too. TEOAEs was recordable in 71.1% of cases. The normal result in acoustic reflex, ABR and ASSR tests was shown just in 11.1% of cases. The clinical symptoms of auditory neuropathy were revealed in 57.7% of children.
Conclusion: Conducting auditory tests sensitive to hyperbilirubinemia place of injury is necessary to inform from functional effect and severity of disorder. Because the auditory neuropathy/ dys-synchrony is common in neonates with hyperbilirubinemic, the OAEs and ABR are the minimum essential tests to identify this disorder.

Background and Aim: Patients with Parkinson&aposs disease manifest oculomotor abnormalities. This is the consequence of basal ganglia impairment.  The most common abnormalities include increased saccade latency, hypometric saccades  and decreased saccade velocity. The purpose of this study was comparison of saccadic parameters using videonystagmography in patients with idiopathic Parkinson&aposs disease and normal subjects.
Materials and Methods: In this cross sectional study, saccadic movements were investigated in thirty patients with idiopathic Parkinson&aposs disease and thirty age matched subjects were 35-70 years old. Saccade latency, velocity and accuracy were quantitatively analyzed.
Results: Results of this study indicated increased saccade latency, reduction of saccade velocity and accuracy in patients with Parkinson&aposs disease(P<0.001).
Conclusion: This study showed that patients with Parkinson&aposs disease manifest saccadic deficits. This suggests dopaminergic control of these ocular movements.

Background and Aim: Tinnitus is the consciousness of sound that arises in the ear or head without any external sound origin. The efficacies of transmeatal low-level laser irradiation for tinnitus treatment were reported before. The aim of this study was to evaluate the effectiveness of low level laser therapy on tinnitus and ECochG and DPOAEs parameters.
Materials and Methods: The study design was prospective, quasi experimental. This investigation conducted on 16 ears (10 patients) with disabling tinnitus. All patients underwent ENT examination, complete audiological evaluation, tinnitus study, ECochG and DPOAEs, and finally completing tinnitus data sheet. The results were compared before and after irradiation.
Results: Means of tinnitus loudness (LMT) and CAP amplitudes were significant different before and after irradiation (p<0.005). There was no any other significant difference before and after low level laser irradiation in subjective loudness, pitch matching annoyance grade of tinnitus and DPOAEs and other ECochG parameters.
Conclusion: Transmeatal low-power laser irradiation with 200 mW seems not to be effective for treatment of tinnitus. This paper is the research brief report. In clinical point of view, this study should be repeated with a greater sample size although our results were statistically important.

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 7ـ9 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 /æ/ 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: 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&aposs articulatory patterns. One of them is voicing. In addition to determine amount of spacial 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&aposs 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: 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&aposs threshold changes in three monthes after receiving the devise in pediatric cochlear implant recipients.
Materials and Methods: This longitudinal study evaluated the potential&aposs 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 differnent sessions, while there was significant difference between apical and basal electrodes&apos 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: Hearing impairment affects all aspect of individual life, specially language and communication skills. When hearing impairment is congenital or occurs early in life, the child's ability to learn optimally through audition, will be affected. The aim of this study was to evaluate linguistic skills of preschool hearing impaired children and compare these skills with normal peers.

Methods: This descriptive cross-sectional study was performed on 38 preschool hearing impaired children that the main handicap was severe to profound hearing loss with ability to communicate orally and 28 normal children with the same cultural and social context. Twenty four non linguistic variables including age, gender, the age of entrance of preschool center, number of hearing aids, etc. were obtained by filling a questionnaire and fifteen linguistics variables including number of utterance, morphemes, correct utterance, noun phrase, ambiguous utterance, correct sentences, compound sentences, etc. were collected by some part of TOLD-P-3 test and three complementary questions. Then we compared the data from two groups.

Results: There were significant differences between number of utterance, number of correct mean length utterance, number of well-formed sentences in normal and hearing impaired group (p<0.000). There were no significant difference between unintelligible utterances, repetitive utterances and bad-formed sentences between two groups(p>0.05).

Conclusion: This study showed a severe deficit in linguistic skills in preschool hearing impaired children.

Background and Aim: Vestibular evoked myogenic potentials (VEMP) originate from the saccule and the inferior vestibular nerve. In this study, the prevalence of VEMP and latency of the p13 and n23 were compared between three groups of individuals, including symptomatic and asymptomatic Meniere's disease cases and normal participants.

Methods: This study was conducted on 42 cases with the mean age of 40.48 years thirty were Meniere's disease patients, of which 19 were symptomatic and 11 were asymptomatic twelve were normal participants. The VEMP were recorded with 500 Hz tone bursts at 120 dBpeSPL. Then the prevalence and latency of the waves were analyzed and compared in the three above mentioned groups.

Results: The prevalence of VEMP in symptomatic Meniere's disease patients (52.6%) was significantly less than asymptomatic individuals (90.9%) and also normal subjects (100%)(p<0.05). There was no significant difference between latencies of the waves in these three groups (p>0.05). The latency of p13 for symptomatic, asymptomatic and normal participants was 16.41, 15.20 and 14.14 ms, respectively and the latency of n23 for these groups was 20.25, 18.77 and 18.50 ms, respectively.

Conclusion: In Meniere's disease, after medical management, the succule probably regains normal function resulting in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely due to involvement of the inner ear and intactness of the nerve. VEMP may be a useful test for diagnosis of Meniere's disease and additionally for monitoring the trend of medical management.