The cut off points of 90th percentile of acoustic reflex thresholds were determined in the normal and sensory hearing loss.All subjects had measurable hearing(ANSI-1969≤110 dBHL) in three frequencies of 500,1000 and 2000Hz.

While hearing loss was more than 55dB, The cut off point was higher in studies that NR responses was included.

In cases that hearing loss was less than 75dB, 90th percentile can be used in diganosis of retrochochlear lesions.Since Acoustic reflexes are absent in both mentioned pathologies in greater amount of hearing loss,It would be less efficient in diffrential diganisis of cochlear and retrochochlear lesions to use acoustic reflex thresholds under the mentioned circumstances.

Hearing aid selection as the first step in modifying the hearing loss is a critical point . people with severe to profound hearing loss need special consideration. In order to determine the amount of gain and output of hearing aids, some formulae are presented. Although most of these formulae are planned for mild to moderate hearing loss, they are used for severe to profound hearing losses. POGO method is one of these formulae.This method, based on halving the hearing threshold, is not suitable for profound hearing loss. There are some considerations in revising this method for severe to profound hearing loss and it’s name has changed to POGO II, too.

 This is a study performed following the study between the years 1980 to 1982 to investigate risk factors and diagnostic and rehabilitative patterns in a group of newborns suffered hearing loss in a city centre. The current findings which have been attained from 1983 to 1988 manifested that just one third of the deaf newborns can be tracked by means of common auditory evaluation tests in the Neonatal Intense Care Unit (NICU). Although these newborns have been followed sooner than the infants in the Well Baby Nursery (WBN). The age for enrolling in the Parent-Infant Program for both groups is approximately 20 month. During these 8 years it has been detected that the common age for taking part in the rehabilitative programs for newborns is 1 year or more greater than that recommended by Joint Committee on infant hearing

Sudden hearing loss is a type of hearing loss that occurs in three successive frequencies by more than 30 dB and in less than 72 hours. Every 10 person in 100000 in the world and 25000 people in USA suffer this kind of hearing loss. The average age of the onset is 43 years old.

It is difficult for clinicians to make parents aware of any disease or permanent handicap of their children.It is crucial to have vivid picture of the reactions to such crisis in order to manage severe psychological effects of the mentioned situations such as depression and unhappiness. Confronting the situation parents have diverse feelings regarding the pregnancy period, birth time and handicap diagnosis and these are the factors that shape the parent’s upcoming reactions. Common feedbacks to the crisis are refusing the problem, keeping their child away from society, the emotions that provoke disappointment, asking about the reasons for hearing loss, referring to religion, condemning the physician, feeling sin and changing doctor frequently. When parent accept the situation and that hearing could not recurrent and understanding the natural reasons back on their child’s handicap, they can manage the situation constructively.

In this article we aimed at studying the function of Melanin in the inner ear. To reach this goal TTS was studied in people with blue or brown eye color. Subjects were 68 male teenagers with normal hearing. Auditory thresholds were obtained by means of high frequency audiometry (.8-8KHz)before and after TTS.  We used narrowband noise with frequency width of 1665-2335Hz, central frequency of 2 KHz, intensity of 105dBSPL and duration of 10 minutes. A significant difference was discovered in the average TTS of this two group in the frequency range of 2-8 KHz. Brown-colored eye boys manifested the least TTS and the blue- colored eyes one the most discovered TTS.

The incidence of severe hearing loss after coronary artery bypass graft surgery has been as rare as 1/1000 surgery (Plasse et al., 1981). To evaluate possible changes in the auditory status, audiograms were taken before and after this operation. Our objectives were to: 1) evaluate hearing losses that were not necessarily severe and 2) examine the factors associated with any auditory insult. we selected patients among a group without any history of hearing problems and the intake of any ototoxic drugs. All patients underwent careful examination and hearing evaluation the day prior to surgery. 6 days after surgery they were examined again and asked about any hearing problems or experience of tinnitus. Various operative details were taken and the post-operative drug record examined. Patients who were too ill for retesting, or who had been given sedative or ototoxic drugs or opiate analgesia, were dropped from the study. The whole procedure was repeated on a control group of 20 patients who were having thorocotomy but without being placed on a cardiopulmonary bypass. From the bypass sample of 40 ears, five of them (four individuals) had an individually statistically significant high-frequency hearing loss. The results showed a statistically significant difference between the bypass group and the control group, with the bypass patients having worse threshold shifts following the operation.Discriminant analyses have shown that those patients suffering hearing impairment may be discriminated principally with four variables: the patient's age, minimum temperature and minimum blood pressure during the operation, and the time on bypass.

Objectives: The current study was performed to establish the prevalence rate of hearing disorders in school age children.
Method: This study has been performed in a randomized manner among 1000 school-age children (500 girls and 500 boys) in the years between1976-1997 in Behbehan. All subjects underwent Audiometric evaluations, Otoscopy, and impedance audiometry. Additionally, parents, children and teachers were interviewed or asked by questionnaires regarding the familial status of parents, familial history of any hearing loss and the awareness of suffering hearing loss. The findings have been prepared in the charts and tables and the relationship between age and gender of the subjects with the incidence of hearing loss has been evaluated via the statistical test X² and hearing loss in left and right ear was compared by T-test.
Results: the findings demonstrated that 6.6% of the subjects suffered hearing loss in one ear (2.2%) or both ears (4.3%). 4.8% of the patients suffered conductive hearing loss while 1.6% suffered sensory-neural hearing loss. In .2% patients complained different types of hearing loss in the ears. Hearing loss was mostly slight and the relationship between age and gender with the incidence of hearing loss was not statistically significant.
Conclusion: Based on the findings we have concluded that in18.4% of the subjects, medical treatment was required and 0.7% of them were in need of rehabilitation. The percentage of the awareness of the hearing disorders among children, parents and teachers was 21.2%, 22.7% and 15.2% respectively.

A 34-year-old female with a history of a sudden mild left-sided hearing loss and high-pitched tinnitus along with fullness in the same ear was referred to the audiology clinic. Hearing fluctuation and variability in other symptoms were also reported. Although no complain of any vertigo or balance disorder was mentioned, light headedness was implied. Differential diagnosis of endolymphatic Fistula and retro cochlear lesion was demanded. Audiologic and radiologic findings of this patient are presented in the article to discuss findings regarding the diagnosis of the suspected disorder.

Introduction: Several animal studies have been performed that demonstrates a relationship between the amount of magnesium ion in the plasma and the hearing thresholds following exposure to noise, Mg++ has been considered as an effective factor in  prevention of noise induced hearing loss in animals.The aim of this study was to discover whether Mg for a long period of time have a protective effect on occurrence of Noise Induce Hearing loss.
Method: The subjects were randomly chosen among individuals who were under training in army service for two months. The subjects were treated in a double-blind manner by placebo and magnesium ion. Threshold estimation and blood examination was performed for all subjects before and after treatment. All subjects were exposed to noise during 8 weeks training in the army.
Results: The statistical difference between two groups which was treated with placebo and magnesium ion was significant.
Discussion: This study is compatible with previous in vivo observations and animal studies demonstrating the protective effects of magnesium on noise-induced impairment of inner ear.

Technology has made people to be exposed to a lot of sources of noise because of the instruments they use at workplace or at home. Dentists are a group of such people who are especially subject to different sources of noise such as high-speed air-turbine headpieces, operated at 300,000 to 400,000 revolutions per minute In the current study we were aimed at measuring noise at the dentists&apos office estimating hearing thresholds in dentists and determining the reason of hearing loss and finally determining the role that work experience e play in the hearing loss occurred.Dentists have been divided into groups based on the work experience and subjects were randomly selected from the dentists of various groups. Sound levels were measured in clinical settings and in a pre-clinical laboratory for estimation of hearing-damage risk among dentists,The findings demonstrated that all dentists regardless of age and gender suffered a notched hearing loss at 6000 Hz. Additionally hearing loss was worse in right ear.Since sound energy of high-speed air-turbine headpieces is mostly concentrated in high frequencies, it can lead in the most possible hearing loss at 6000Hz.

Sound is an inseparable part of human life and provides us with lovely experiences such as listening to music. Musicians from classical orchestras to rock groups are exposed to high decibel of sounds. Musicians playing percussion musical instruments are exposed to high level of impact noise and players of Brass musical instruments are highly exposed to noise peaks higher than 100dB. Woodwind players are enduring the risk of posing directly in front of Brass players. Based on the above-mentioned risks for hearing loss clinical consideration of noise induced hearing loss in musicians is highly required.In the current study we were aimed at examining hearing stratus of classic and traditional musicians by means of pure tone audiometry in Islamic Republic of Iran Broadcasting. 33 subjects were evaluated aged between 22 to 59 years old. Their musical experience was variable between 6 to 45 years.The study demonstrated that most of the musicians in this study suffered bilateral high frequency hearing loss with a notch in the frequency range of 4-8 KHz.

Introduction: We estimated the noise in an industrial shoe factory to determine the effect of noise in the workplace on the hearing status of the workers in such environments.
Materials and method: the intensity of noise in dB in different parts of the factory was estimated. Then working people in each part was selected randomly and their hearing thresholds were evaluated by Conventional audiometry.
Results: The results demonstrated that 23% were required to estimate thresholds more precisely and 95 needed close examination by Otolaryngologist. Besides, 10% of the workers suffered sensory neural hearing loss whose 2% of them diagnosed as NIHL.
Discussion: Since the mentioned factory has good hearing conservation program for the workers, it seems that promoting the program can decline the number of noise induced hearing losses to the least numbers.

In the current investigation we gathered information about the hearing thresholds, types of hearing loss, types of tinnitus, and also the prescribed tinnitus maskers for the veterans. We were aimed at determining the percentage of tinnitus, audiogram shape and its relationship with tinnitus, and the percentages of veterans using tinnitus maskers. The needed information was prepared by studying the audiograms and file of the patients.  The results of the investigation have been prepared here in details.

Background: Many Endogenic and exogenic factors can affect the individual&aposs susceptibility to noise exposure, for instance middle and outer ear characteristics, the amount of oxygen transmission, skin color, medical history, mental state and the patient&aposs attention, age, cigarette smoking and many otjher factors affect the amount of noise induced hearing loss and acoustic trauma.The current study was aimed at investigate the impact of various Endogenic and exogenic factors on the amount of PTS and TTS in veterans in Hamedan province.
Results: The results of the study manifested that:- Veterans with tinnitus suffered more hearing loss than patients without this symptom.- Extended intensity of noise and exposure time to war noises can exacerbate the amount of hearing loss in veterans who had fight more.- The degree of hearing loss in patients who had previously suffered middle ear infections or otitis or the familial history of hearing loss was more than people without such history
Discussion: The findings of our study in compatible with the results of other similar studies and confirms the effect of different pathologic and non-pathologic factors on the degree of noise induced hearing loss.

Tinnitus from the Latin word tinnire meaning ringing is the perception of sound within the human ear in the absence of corresponding external sound. The most common cause is noise induced hearing loss. Tinnitus may be induced by an acoustic trauma or a permanent noise in the workplace. In case that Tinnitus is induced by acoustic trauma the site of lesion is commonly the base of the cochlea. Tinnitus in the senile population is mostly accompanying presbycusis. Although the incidence of permanent tinnitus following noise exposure is high, little is published about this issue. In the current article we are aimed at studying the prevalence of tinnitus in Minoo and other manufactures.

There are increasing evidences about the vestibular damage caused by the exposure to noise. Histological and functional derangements of the vestibular system have been reported in laboratory animals exposed to high levels of noise. However, clinical series describe contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise induced hearing loss (NIHL). Animal studies have proved that crista ampullaris bears the most disturbances, though some damages have been also detected in macula of the utricle and saccule and utricle. These changes have been induced due to acoustical pressure on the vestibular labyrinth. The findings from the experiments regarding vestibular function in patients suffering NIHL have shown a paramount diminish in vestibulo-occular Reflex (VOR). The correlation among NIHL, VOR and unilateral caloric weakness were statistically significant which can be due to a common mechanism of disturbances in the function of cochlea and vestibule.

The most common contributing factors in inducing hearing loss in adults are aging, exposure to noise and the interaction among these factors with other parameters. Individual parameters are also effective in the extent of hearing loss which is produced. Being aware of Vulnerability factors such as physical parameters, Auditory and non-auditory factors can be useful in considering a good hearing conservation program for noise induced hearing losses.In the current article we are aimed at introducing three important parameters and their sub-divisions pertaining to this issue.