Method & Material: This study examined the speech in noise test in 60 school age children with otitis media with effusion and 30 school age children with normal hearing in +5, 0 and -5 dB signal to noise ratio. The mean of age was 8.05 in study group and 8.25 in control group. Speech in noise test were performed for study group and control group in quiet an in noise. Speech noise presented ipsilaterally in both groups.Finding: The correlation of mean of SDS in +5, 0 and -5 dB signal to noise ratio between study group and control group, is significant.

Auditory Hallucination or Paracusia is a form of hallucination that involves perceiving sounds without auditory stimulus. A common is hearing one or more talking voices which is associated with psychotic disorders such as schizophrenia or mania. Hallucination, itself, is the most common feature of perceiving the wrong stimulus or to the better word perception of the absence stimulus.Here we will discuss four definitions of hallucinations:1. Perceiving of a stimulus without the presence of any subject2. hallucination proper which are the wrong perceptions that are not the falsification of real perception, Although manifest as a new subject and happen along with and synchronously with a real perception3. hallucination is an out-of-body perception which has no accordance with a real subject In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid, substantial, and located in external objective space. We are going to discuss it in details here.

Objective: A research was conducted to assess the phonological awareness in hearing-impaired children in comparison to normal children. In this context, we discussed about the ability of these children in identification of rhyme and word segmentation to syllables.
Method and Material: The sample of this study is composed of 320 children, 160 normal & 160 hearing-impaired with a hearing-loss. Of over 70 dB, studying in the 1st t 4th grade of the primary schools in Tehran. They are divided into two groups at each level (20 girls & 20 boys).
Results: 1) Hearing-impaired children&aposs scores on test related to rhyme and syllable is lower as compared with normal children. 2) Hearing-impaired children are more potent on test of word segmentation to syllables in comparison to that related to rhyme, while normal children are more successful on test of word segmentation to syllables as compared with that related to rhyme.

Discussion: Hearing is an important factor in phonological awareness. Formal education at special schools doesn&apost compensate for the hearing impairment as to development of the phonological awareness.

Objective: A survey on hearing state of blind schoolboys in Tehran.
Method and Material: This cross-sectional descriptive survey was conducted on 640 ears of 320 blind schoolboys of 5-23 years old as a hearing screening in Tehran blind schools, 2000-01.
Results: 20.94% was hearing-impaired of whom 13.75% had bilateral and 7.19% had unilateral hearing loss. 15.16% of students suffered from sensory-neural hearing loss (SNHL), 1.56% from conductive hearing loss (CHL) and 0.62% from mixed hearing loss (MHL), that is, SNHL occurred 10 times more than CHL. Hearing loss was often mild and moderate, and audiogram configuration was primarily high tone loss (HTL). On the whole, 8.13% of students needed medical treatment, 15.13% needed audiological rehabilitation and 3.44% of them were in need of both medical and rehabilitation Intervention. General information about hearing problem was very low among students, their parents and teachers, which was 26.87%, 20.9% and 22.39%, respectively. There is significant relation between SNHL and parents&apos relationship.
Conclusion: The prevalence of hearing loss in blinds is higher than in normal-visions. It is often sensorineural. So, it is important to identify these children through hearing screening (Using more high frequencies) and to conduct medical as well as rehabilitative intervention.

Objective:Determining the prevalence of hearing loss and correlated factors in clients referring to audiology clinic of Buali hospital.
Method and Material: This cross-sectional analytic-descriptive survery was carried out on six thousand and twenty ears of 3010 clients (1651 ,ae amd 1359 female) in Audiology clinic of Buali hospital , during Sept 2000 to Sept 2001.
Results: Hearing loss is the most common reason for referring the clients (20.5%). 1319 ears (21.9%) Showed sensorineural hearing impairment and conductive and mixed hearing loss are observed in 1059 (17.6%) and 234 (3.9%) ears, respectedly. Hearing loss degree most cases is mild (14%) in both ears. There is no significant difference between male and female hearing threshold means (p>0.05) ‘ but a significant difference between hearing thresholds is observed in terms of age (p<0.05). Audiogram configuration in most cases is flat (55.1%). Otoscopic examination reveals abnormal condition in 2333 ears (38.8%) . 37.2% of the studied cases have abnormal tympanogram mostly type B (15.9%). 2.2% of the clients wear hearing aid that mostly have B.T.E ones (1.5%). 6.2% of the clients , depends on their hearing impairment type and degree need rehabilitation services.
Conclusion: The results are Valid only in the context of this study and it&aposs generaliztion needs further researches.

Objective: Comparing analog and digital hearing aids reducing disability caused by hearing deficiency among moderate to severe sensorineural hearing-impaired persons.
Method and Material: This descriptive-analytic study was carried out on two groups of subjects participated in this study in some audiology clinics of hearing aid since May 2002 to October 2003. Twenty subjects wore analog hearing aids and twenty one subjects wore digital hearing aids. In this study , no subject had previous middle ear or psychological problems. APHAB questionnaire was completed before using hearing aid and 2 months after to determine benefit of hearing aid use. Results: Total score mean of APHAB inventory before and after use of analoge hearing aids were 52.215+6.420 and 32.300+3.443 respectively. Also total score mean of APHAB inventory before and after use of digital hearing aids were 54.9252+9.028 and 26.321+10.916 respectively. There was no significant difference between total mean score of APHAB inventory before and after using analog and digital hearing aids (P=0.058).While there was significant difference between total mean score of APHAB questionnaire before and after use of analog hearing aids (P<0.001) and also before and after use of digital hearing aids (P<0.001). Moreover age, gender , litracy level , occupation , degree of hearing loss and manner of hearing aid usage did not have significant effect on APHAB results. Configuration of loss had siginficant effect on aversiveness subscale before and after use of analog hearing aids (P=0.008). Previous experience and duration of hearing aid usage had significant effect on aversiveness subscale before and after use of digital hearing aids (P=0.043) and (P=0.024), respectively , while all of these three items did not have significant effect on total mean score of APHAB inventory and also total mean scores of three subscales of ease of communication , reverberation and background noise.
Conclusion: Comparing to analog hearing aid , digital one is significantly benefitial for reverberation and background noise for hearing-impaired persons , but it has no benefit for ease of communication and aversiveness that may be arised from effects of the individual expectation , psychological and personal factors.

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 overemphasized. In spite of the negative results if still there is any suspicoin, total facial nerve exploration is necessary.

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 seems to repeat syllables faster than the girls do.

Objective: determining difference limen for Frequency (DLF)in string musicians.
Materials &Methods: This case-control study was conducted on 15 string 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: 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: Risk factors including asphyxia , meningitis , form of delivery, etc. may cause hearing loss in neonates results in speech and language deprivation , emotional and educational problems. The aim of this study was to determine the prevalence of hearing loss and its relationship with risk factors among neonates hospitalized in neonate intensive care unit (NICU).
Materials and Methods: It was a cross-sectional study on 234 NICU hospitalized neonates in Ghaem and Imam-Reza hospitals of Mashhad. Epidemiologic and pathologic information were obtained. Otoacoustic emissions were done in all of neonates. Patients referred to the second otoacoustic emissions (OAEs) and patients failed in the second test controlled by auditory brainstem response (ABR).
Results: Hearing abnormality was found in 11 neonates (4.7%) including 2 girls and 9 boys.   (1 neonate with mild, 2 with mild to moderate, 2 with moderate to severe, 1 with sever to profound hearing loss and 4 with auditory neuropathy). Hearing abnormality has a significant greater incidence in group with apgar £5 and in patients with icterus (in need with transfusion).
Conclusion: Incidence of hearing loss in NICU hospitalized neonates are greater in comparison with general population. It has a greater incidence in group with icterus (in need with transfusion) and apgar £5,so,a comprehensive hearing screening program must be applied for early identification and intervention.

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: Auditory neuropathy (AN) can be diagnosed by abnormal auditory brainstem response (ABR), in the presence of normal cochlear  microphonic (CM) and otoacoustic emissions (OAEs).The aim of this study was to investigate the ABR and other electrodiagnostic test results of six patients suspicious to AN with problems in speech recognition.
Materials and Methods: this cross sectional study was conducted on 6 AN patients with different ages evaluated by pure tone audiometry, speech discrimition score (SDS) , immittance audiometry , electrocochleography , ABR, middle latancy response (MLR), late latency response (LLR), and OAEs.
Results: Behavioral pure tone audiometric tests showed moderate to profouned hearing loss. SDS was so poor which is not in accordance with pure tone thresholds. All patients had normal tympanogram but absent acoustic reflexes. CMs and OAEs were within normal limits. There was no contralateral suppression of OAEs. None of cases had normal ABR or MLR although LLR was recorded in 4.
Conclusion: All patients in this study are typical cases of auditory neuropathy. Despite having abnormal input, LLR remains normal that indicates differences in auditory evoked potentials related to required neural synchrony. These findings shows that auditory cortex may play a role in regulating presentation of deficient signals along auditory pathways in primary steps.

Background and Aim: Hearing loss results in impairment of  muscles coordination and survival essential that are engaged in motor speech timing tasks. It will negatively affect the acquisition of speech sounds. The purpose of this study was to compare the oral diadochokinesis in normal-hearing and hearing - impaired adolescents
Materials and Methods: This research was conducted on sixty-one adolescents aged 15-18 years old. Forty-six had moderately severe, severe, or profound hearing loss and fifteen were normal. The time spent to perform each oral diadochokinesis tasks was measured by speech analyzer of Dr. speech software, version four.
Results: Results indicated that hearing - impaired performed significantly slower on all speech timing tasks than their normal hearing peers except those with moderately severe hearing-impaired group. There were significant differences between profound hearing-impaired group and both other groups.
Conclusion: The results of this study point out  the motor speech problems in hearing impairment. The differences, in general, indicate that speech-timing coordination deficits are compromise with hearing loss degree.

Background and Aim: Central auditory processing disorders (CAPD) may have a variety of etiologies therefore, performing CAPD tests seem inevitable. Behavioral tests such as synthetic sentence identification (SSI) has gained considerable popularity because of high sensitivity to brainstem and cortical lesions, high diagnostic ability,  cost-benefiting, and also limitations of electrophysiologic tests. The purpose of this study was to prepare a Farsi-language version of SSI and to perform a primary evaluation. 
Materials and Method: Farsi SSI test was made and recorded on CD. Then sixty 20-to 35- year old normal-hearing participants were evaluated in audiology clinic, Faculty of Rehabilitation Sciences Iran University of Medical Sciences in three months.
Results: There is no significant difference between scores of Farsi and original versions of SSI. Gender has no significant effect on the scores.
Conclusion: According to this results, Farsi SSI is comparable to the original one. It can, therefore, be used in CAPD test battery.

Background and Aim: Since knowing the mechanisms which evoke non-fluency is the first step in the treatment of stuttering, and there are very few researches in Persian which consider the role of the linguistic factors behind  stuttering , this study is an attempt to provide answers to some of numerous questions about stuttering by comparing  the stuttered words` type in stuttered children and adults. 
Materials and Methods: In this study stuttered people were divided into 5 age groups as follows: 3-6, 7-9, 10-12, 13-16, and older than 17 years old. Each group had ten participants. Forty-two of the 50 participants were male , and the youngest person was 3 years old and the eldest one was 32 years old. The study method involved recording at least 5 minuets of spontaneous speech of every one who was diagnosed of suffering from stuttering by two speech and language pathologists. The percent of non-fluency on every word&aposs type was determined where a content word was followed or preceded by a function word (Function-Function-Content words and Function-Content words contexts). Then these findings were analyzed by Kruskal-Wallis and Mann-Whitney tests. 
Results:  The results of this study show while function words are dominantly more stuttered than content words in children less than 13 years old in Function-Function-Content words context, we consider more disfluency on content words and second function word by getting old. We consider more stuttering on function words in children less that 13 years old in Function-Content words context too and increased non-fluency on content word by growing up. Results also show meaningful differences between the fifth group and others in the amount of stuttering on second function word in the Function-Function-Content words contexts and also between the first group and the others in amount of non-fluency both on function and content words in Function-Content words context.
Conclusion: people who stutter from Farsispeakers populations exhibit almost differential patterns of disfluency in different ages. Young speakers who stutter are predominantly disfluent on function words. There is an exchange of disfluencies from function to content words as speakers get older. Disfluencies on both function and content words are so rarely in Function-Content words and Function-Function-Content words contents. These findings support the view that stuttering on function words in children is a way of getting time to complete the next content word&aposs plan. These exchange findings are similar to what is found in English and Spanish languages and explained by the EXPLAN model.

Background and Aim: Tinnitus represents the perception of sound without an external stimulus. The prevalence of tinnitus ranges from 3% to 30%. In most cases its etiology is unknown. Tinnitus can be classified as pulsatile or nonpulsatile. Nonpulsatile form is the most common form and almost exclusively subjective in nature.  There is a range of condition attributed to nonpulsatile high frequency tinnitus (acoustic neuroma,  Meniere&aposs disease, ototoxic agents, noise exposure...). There are many studies about form, site, loudness, and frequency of tinnitus and how it can affect the quality of patient life.
Materials and methods: This was a descriptive and analytic study. Thirty-six patients (23 men and 13 women) with mean age 53.1 year old with subjective tinnitus evaluated in pezhvak audiometric clinic in Mashhad .The data consisting of age sex, loudness, frequency form and site of tinnitus. Evaluation of affects of tinnitus on the quality of life and habits was performed with a tinnitus questionnaire (TQ).
Results: Tinnitus was unilateral in 64% of cases right site was more common. Mean  pitch was 7.03 kHz and average loudness was 3.8 dB SPL. SDS was in normal range in all of patients. There was a high frequency sensory neural hearing loss (above the 4 kHz) in most of the patients. The greatest score (60.3%) of TQ related to intrusiveness aspect. Sleep disorder has the lowest score (39/3%). Global score was 52.4%.
Conclusion: Nonpulsatile subjective tinnitus has a broad range of etiology with unknown mechanism in most cases and without any history of underlying disease in a large group of patients. This symptom mostly involves the patients` lifestyle that is intrusiveness aspect in comparison with the other aspects including sleep, hearing and somatic complaints. There is no cure for most patient and more studies are needed in the future.

Background and Aim: Mismatch negativity (MMN) is one of auditory evoked potentials that occurs about 100-250 ms after stimulus onset. The MMN waveform is elicited by a discriminateable change in a sequence of repetitive homogenous stimuli. This change can be in intensity level, frequency, or duration of auditory stimuli. The purpose of this study was to obtain MMN waveform using tonal stimuli and to investigate its changes during changes in age.
Materials and Methods: The study was prescriptive-analytic cross-sectional. The participants were sixty children aged 4 to 9 year.The Stimuli were at 80 dB pe SPL. A 1000Hz tone and a 1500 Hz tone were used as standard and deviant stimuli, respectively. Probability of deviant stimuli was 20%. Trials were recorded using surface electrode placed at four locations on the head.
Results: The MMN waveform does not exist in 22.5% of the children. Also, determining of MMN peak in 22.5% was not exactly possible. In other subjects, a significant negative correlation was observed between latency of MMN and age, but not for age and amplitude for this negativity.
Conclusion: This study confirms that the MMN may not be seen in normal people. Also there are maturational changes in MMN waveform.