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.

Background: The current article is aimed at evaluating speech recognition scores in hearing aid wearers to determine whether nonsense syllables are suitable speech materials to evaluate the effectiveness of their hearing aids.
Method: Subjects were 60 children (15 males and 15 females) with bilateral moderate and moderately severe sensorineural hearing impairment who were aged between 7.7-14 years old. Gain prescription was fitted by NAL method. Then speech evaluation was performed in a quiet place with and without hearing aid by using a list of 25 monosyllable words recorded on a tape. A list was prepared for the subjects to check in the correct response. The same method was used to obtain results for normal subjects.
Results: The results revealed that the subjects using hearing aids achieved significantly higher SRS in comparison of not wearing it. Although the speech recognition ability was not compensated completely (the maximum score obtained was 60%) it was also revealed that the syllable recognition ability in the less amplified frequencies were decreased. the SRS was very higher in normal subjects (with an average of 88%).
Conclusion: It seems that Speech recognition score can prepare Audiologist with a more comprehensive method to evaluate the hearing aid benefits.

Exposure to noise is a one of the common problems in any industrial places. Many solutions have been introduced to overcome the deleterious effects of noise pollution maintaining and repairing systems in the equipments, environmental control and hearing conservation systems are some of these solutions that could be mentioned.
There are various types of Hearing protection devices and each one is useful under special circumstances. Commonly, different Hearing protection devices have a particular brochure to introduce information about the manufacturers and the quality of noise reduction in that special production.
Three different methods are commonly used to determine the noise reduction factor in various Hearing protection devices. All these methods have been presented based on the mathematical evaluations and according to the spectral features of the sound existing in the environment and then the sound pressure level is determined in dBA. In the current article we will have a look on the mentioned arithmetic models and their special characteristics.

There are some insufficiencies in the Hearing Conservation Program that are exponentially exacerbated by lack of the standard and observation for this program and little interest in team work activities. Regarding the noise measurement instruments, limitation in the measurement lack of the equipments and also incomplete evaluation are clearly detected.The performed investigations have demonstrated that most of the industrial centers have no baseline auditory curve and sometimes do not intend in hearing screening evaluations. that is mainly because of the need for sound protected environment and calibrated instruments and also 14 hours of sound rest before the experiment.Her the problems in performing hearing conservation program is discussed in more details.

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: workers in the spinning company were audiologically evaluated to estimate the impact of industrial noise of the factory on their hearing status.
Material & Method: subjects were 185 workers of the spinning post in the first flat of yarn. Hearing thresholds were compared at the beginning of their employment and after 1 to 19 years of work experience.
Results: the percent of hearing deficit was lower than the data reported by WHO.
Discussion: efficient application of hearing conservation devices has had a remarkable effect on hearing status of workers.

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.

Workers in the Municipality of Tehran expose to high level of noises. The major sources of noise are the vehicles for garbage collection, Asphalt production and its usage in construction of pavements, Repairing motor vehicles, technical and constructive implementation including road and building construction , Forging, Concrete planning, Welding, Building structure and  etc.Although most of such activities are performed by Contractors, many workers are exposed to high levels of noise during such processes. Since hearing conservation program is a duty for the Municipality, we have managed to use some new protocols to prepare a convenient and quiet environment for workers that is going to be discussed here in the present article

Prescription of hearing aid is an extensive special category of knowledge in the field of audiology. This article is aimed at discussing the function of hearing aid and also management of patients in the noisy environments and presenting solutions to overcome problems regarding to this issue along with taking a look to the equipments prepared nowadays to cope with noisy situations.

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.

Hearing loss, even when limited to 1 ear, has been indicated as a handicap to communication and learning. Although this does not seem true based on my clinical impressions, there are no objective data available to evaluate, or even infer, what type of hearing loss can become a true handicap to overall academic achievement. Presented herein are findings that imply, although do not prove, the potential academic handicap of unilateral hearing loss. This study prospectively analyzed the audiologic and otologic screening tests in a university over a 9-year period. The University of Tokyo is one of the leading universities in Japan the students examined undoubtedly had academic ability well above average, for the entrance examination is one of the most difficult to pass in Japan. The potential handicap to academic achievement caused by hearing impairment was evaluated by comparing the prevalence of hearing impairment among the study population

Objectives :Determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, impedance Audiometry and questionnaires.
Methods and Materials: This study was can-led out in a cross - sectional descriptive survey - on 1000 students (500 girls and 500 boys) among the student of primary school of EslamAhad Gharh, academic year 1376-77
Results: 1- Otoscopy examination abnormal conditions of external ear canal was found in 13.65% of cases mostly impacted ceruman (13.3%). Abnormal conditions of external ear canal was more prevalent in girls than boys and the difference was statistically meaningful in the right (P V=0 .012) and left (PV=0.043) ear. Abnormal tympanic membrane was seen in 6.75% of cases mostly retraction (295%).
2- Impedance Audiometry: 11.05% abnormal tympanograms were observed, mostly type C (4.1%).
3- Pure Tone Audiometry: An overall 9.7% hearing loss was found in this population including 3.5% bilateral and
6.2% unilateral hearing loss. 4.15% of population suffered from SNHL observed mostly in boys and conductive. Hearing loss mostly in girls and the difference was statistically meaning in the left ear (PV=0.03).25.8% of cases were in need of medical care and surgery and six of them (l.e 0.6%) were in need of rehabilitation services.Family background showed on effects on the hearing disorders.Only 11. 4% of parents, 13.4% of teachers and 14.4% of afflicted students were aware of the problem.

Objectives: determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, Impedance Audiometiy and questionnaires.
Methods and Materials:This study was carried out in a cross - sectional descriptive survey - on 1200 students (600 girls and 600 boys) among the student of primary school of Neishabbor, academic year 1376-77
Results:1- Otoscopy examination abnormal conditions of external ear canal was found in 14.1% of cases mostly impacted ceruman (13.6%) Abnormal conditions of tympanic membrane (0.4%) and foreign body 0.16%. Abnormal conditions of external ear canal was statistically unmeaningful. (P V=0 .8)
2- Impedance Audiometiy: 5. 75% Abnormal tympanograms were observed, mostly type C (3.15%)
3- Pure Tone Audiometry: An overall 5.5% hearing loss was found in this population including 3% bilateral and 1.25% unilateral hearing loss. Only conductive hearing loss was found in this population (2.7% in right ear and 3.5% in left ear), PV=0.9.Hearing loss observed mostly in girls but the difference was slight.Family background showed no effects on the hearing disorders.9.8% of cases were in need of medical care and 0.3% were in need of rehabilitation services.Only 28.8% of parents, 36.3% of teachers and 40.9% of afflicted students were aware of the problem.

Method and Materials: This cross - sectional survey is carried out in pediatric clinic department of audiology faculty of rehabilitation, TMSU, on spring 1998. 102 top grade ranking children with normal hearing threshold

Results:1- The thresholds were not significantly different at any frequency (P>0.05) in test re-test trials.
2- The test minus re-test threshold for individual ears showed clinically reliable and acceptable range 0-10dB SPL for at least
99.74% of the ears at all frequencies.
3- The threshold differences between right & left cars in two test sessions were not significantly different (P>0.05) except for 14KHz.
4- High- frequency threshold in two test sessions showed no significant difference between girls & boys at all frequencies (P>0.05) (except for 16 & 20 KHz in right ear and 10 KHz in left ear).
Conclusion: This test can be used for evaluation of individual high-frequency threshold in all frequency as test re-tests tria1. Moreover, this test may use as a beneficial tool for monitoring different endogenous and exogenous auditory pathologies.
Consideration: it is found that this research is valid only among situation of this project. Any generalization needs further research.