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.

The study included 80 patients treated for sudden deafness over the last 5-7 years. Case history, laboratory findings, pure-tone audiogram and electronystagmography (ENG) findings were noted. If any abnormalities had been recorded in ENG studies, the studies were redone. ORL status was redefined and audiograms were obtained in all patients. When becoming ill, the 80 patients had not differed from the normal population in common cardiovascular risk factors. None of them had had signs of viral infection (paired serum samples had been taken at 2-week intervals routine examinations had been done for common viral antigens). As many as 31 of the 80 patients with acute hearing loss had had abnormalities such as spontaneous nystagmus (PN), hypoexcitability (HE) and directional preponderance (DP) in the bithermal caloric tests (+44 degrees C, + 30 degrees C) of their ENG studies. Twenty of the 31 patients still had abnormal ENG studies after 5-7 years. Only 1 subject had positional nystagmus, and none had subjective vertigo. Patients with an abnormal ENG study showed a poor recovery of the speech reception threshold, whereas those with a normal ENG study showed slightly significant (p less than 0.05) recovery.

 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

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.

Transmission of intracranial pressure (ICP) to the perilymph is performed through cochlear aqueduct and also by other ways. Indirect measurement of perilymphatic pressure may be investigated by observing tympanic membrane (TM) displacement during stapedial reflex contraction, the tympanic membrane displacement (TMD) measurements. This non-invasive technique of examining intracranial pressure (ICP) can be effective in patients suffering abnormal cerebral pathology that could lead in Changes in ICP. It would also be effective in regular monitoring of hydrocephalus patients. This study has a look on this technique which has been reported to provide a reliable, non-invasive measure of ICP.

Tactile aids, which translate sound waves into vibrations that can be felt by the skin, have been used for decades by people with severe/profound hearing loss to enhance speech/language development and improve speechreading.The development of tactile aids dates from the efforts of Goults and his co-workers in the 1920s Although The power supply was too voluminous and it was difficult to carry specially by children,  it was too huge and heavy to be carried outside the laboratories and its application was restricted to the experimental usage. Nowadays great advances have been performed in producing this instrument and its numerous models is available in markets around the world.

Auditory perceptual and visual-spatial characteristics of subjective tinnitus evoked by eye gaze were studied in two adult human subjects. This uncommon form of tinnitus occurred approximately 4-6 weeks following neurosurgery for gross total excision of space Occupying lesions of the cerebellopontine angle and hearing was lost in the operated ear. In both cases, the gaze evoked tinnitus was characterized as being tonal in nature, with pitch and loudness percepts remaining constant as long as the same horizontal or vertical eye directions were maintained. Tinnitus was absent when the eyes were in a neutral head referenced position with subjects looking straight ahead. The results and implications of ophthalmological, standard and modified visual field assessment, pure tone audio metric assessment, spontaneous otoacoustic emission testing and detailed psychophysical assessment of pitch and loudness are discussed.

Nowadays OAE have a special role in electrophysiological examinations and also remarkable application in infants&apos hearing screening test. In the current article we have focused attention on the physiological fundamentals of OAE and tried to explain the trends in physiological studies that finally led to discovering the acoustic radiations by "David Kemp". By studying this article we can conclude that inner ear cannot be pondered just as a transformer that change the movements of the inner ear&aposs fluid to the neural signal, rather it should be considered as an active organ that can produce energy and also control the other active mechanisms involved in hearing.

Recent studies have demonstrated that outer hair cells play two functional roles in the ear: one is the sensory function and the other is motor one. The function of OHCs in being trigered with very poor signals can not be overlooked. This mechanism would lead in improving the sensitivity of the ear. As stimulus intensity increases, little by little, OHC will reach its saturation level and finally the amplification effect decreases.Otoacoustic emissions could be reverberations produced by the responses of outer hair cells .Any decrease in the number of OHCs can cause a mechanical split in the fine tuning mechanism of the organ of corti and result in hearing loss.

Many of the CP angle tumors are acoustic neuroma, vestibular schowanoma or 8^th nerve tumor. This kind of tumor is benign histologically. Big size ones can cause neurological symptoms such as cerebellar imbalance, edema and cranial nerves dysfunction. Acoustic neuroma is mostly unilateral and audio logical findings manifest a unilateral hearing loss. Although big size tumors can lead to bilateral audio logical symptoms which can affect the findings of hearing assessment. Here, a 31 year-old patient suffering right ear vestibular schowanoma have been reported. changes in left ear pure tone results, acoustic reflex measurements and ABR in addition to hearing loss in the right ear have been demonstrated.

Background: hearing loss is a major health care problem that tends to retard the developmental milestones of children. It takes early detection and intervention to avoid a permanent loss in acquisition of speech and cognitive functions. Hence, the importance of hearing screening in all children especially in the developing world for accurate statistics and early intervention is clear. This work was aimed at predicting hearing in children by means of acoustic reflex measurements
Method: In this study which was performed in 1995, 146 ears(86 children aged between 5-10years old referring to audio logy clinic in Tehran university of medical sciences between august 1995 and February 1996) were evaluated (amongst 95 were normal and 51 ears with SNHL<84dB).the methods Niemeyer and Destrehan formula ,Lilly2 equation, un weighed Sensitivity prediction by acoustic reflex, weighed sensitivity prediction by acoustic reflex to establish their clinical viability.
Results: findings demonstrated that weighed sensitivity prediction by acoustic reflex(WASPAR) have a good correlation with conventional audiometric evaluation(K=.78) and also it has good sensitivity, Specificity , Negative predicted value(NPA) and positive predicted value (PPV).
Conclusion: In case that conventional audiometry is not applicable, WASPAR is a good objective choice in lieu of subjective tests.

Noise pollution is the problem of the industrial world that along with noised induced by traffic has become a problem in human life.This is more problematic in Tehran because of the traffic and the accumulation of small or large industries. People are profoundly exposed to the high level noises and there are increasing demands to solve the problem of noise in Tehran or at least alleviate it.In the current article we will have a brief and quick look to the noise making industries, the reason behind the noise pollution and the strategies for facing the disturbing industries.

Industrialization has had many complications for human beings and has been a threat to social mental and physical health. Vibration induced noises in the workplace is one of the main devastating factor in producing hearing loss in workers.Recently, several investigations on the issue of noise pollution and noise dosimetry and also Noise induced hearing loss have been developed. In the current article we will have a look and sometimes reconsideration on the results and of these studies and will discuss the findings in regard to noise control and management in details.

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.

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.

As the industry develops in the societies, human being is more likely to exposed to high level of noises and be at risk of hearing loss. Urbanism and working in the situation which are not in accordance with the personal nature make people even more susceptible to risk factors of hearing loss.   Exposure of workers to industrial noise has been the subject to several studies and it seems that reconsidering the situations in both society and nature can be a key to change environment for decreasing noise in the society.For example in Tehran, geographically, the slope of the earth from north to south is 5-10% which is a main factor contributing in noise pollution.Moreover, the source of most outdoor noise worldwide is mainly construction and transportation systems including motor vehicles, air craft noises and rail noises. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.In the current article we have examined both conditions in the hearing condition of workers with high levels of noise exposure.