Background: Severe birth asphyxia (apgar<7 at the 5th minute of birth) is recognized as a hearing loss risk factor by the joint committee on infant hearing (JCIH). About half of the newborns with hearing loss do not indicate any sign and risk factor at birth. Accordingly, the joint committee recommended performance of hearing screening test in 2000, especially for babies born with risk factors.Objectives: The aim of this study was to evaluate hearing loss in asphyxiated neonates. Early diagnosis would result in early treatment of these newborns.Patients and Methods: We assessed the relationship between asphyxia and hearing impairment in newborns admitted to a referral hospital, Tehran, Iran within 3 years (2003-2006). Hearing problems were diagnosed and followed by otoacoustic emission (OAE) in the third and fifth days of birth. Asphyxiated neonates with abnormal OAE were referred to an ENT specialist, second OAE and tympanometry were carried out after 2 weeks. Based on the results, newborns underwent treatment or were discharged.Results: Of 149 asphyxiated neonates, 80 had mean first minute apgar score of 4.01, and mean 5th minute score was 7.24. Two percent (3.149) of asphyxiated neonates had abnormal OAEs. No statistical correlation was found between the 5th minute apgar score and abnormal OAE (P value=0.391). However, a significant relationship between the mean birth weight and abnormal OAE (P value=0.0406) was found.Conclusions: It seems that birth asphyxia is not correlated with hearing loss.

Background: hyperbilirubinemia is one of the most disease in term and preterm neonate. A bilirubin level of more than 85 umol/l (5 mg/dL) manifests clinical hyperbilirubinemia in neonates, since with increase level of bilirubin in body many problems like sclera icterus, yellowing of the face and central dysfunction may be achieved. Unfortunately in Neonatal unit just use otoacoustic emission (OAE) to screening of hearing, but this test only evaluate the cochlear and not evaluate the 8th nerve and central auditory pathway, since central hearing loss easily be miss.And after a times a parent of children because inattention of Infant to sound refer to a pediatrician.Methods: This pilot study conducted with 9 neonate (3 male, 6 female) with hyperbilirubinemia more than 20 mg/dL that had been referred to pediatric audiology clinic of rehabilitation faculty of tehran university of medical science. We use otoacoustic emission (OAE) and behavioral observation audiometry (BOA) to evaluation of auditory system.Findings: among 9 neonates that evaluated with otoacoustic emission (OAE) 6 neonates have perfect OAE, 2 neonate abnormal OAE and 1 neonate in ambiguous range. In behavioral observation audiometry (BOA) only 2 neonates show behavioral auditory response, even with max of intensity, and others haven’t any response.Conclusion: we can conclude that in neonate with hyperbilirubinemia more than 20 mg/dL and absent response in BOA, the OAE test can’t be a sensitive test to predict hearing loss in neonate with hyperbilirubinemia. Since it is essential in Neonatal unit of hospital not use only OAE, also use BOA or auditory brainstem response (ABR) test.

Objective: OAE an audiologic study for diagnosis of exteracochlear auditory neuropathyMethod & Material: Immitance Audiometry, OAE and ABR and Rehabilitation intervention was performed for 3 children suffered from Kernictrus.Conclusion:-OAE in the from of screening, distorted product and transient evoked -otoacoustic emission has to be added to our audiology test battery.-OAE studies have their own merit when we are clinically involved with the diagnosis of especial clinical entities like neonatal hypoxia, kernicterus, multiple sclerosis, meningitis and meningoencephalitis.-case selection for cochlear implantation needs knowledge of patients' OAE results.-In the case of intracerebral auditory neuropathy the need for other rehabilitative measures will be better understood.

Evoked otoacoustic emissions (OAEs) are sounds generated within the inner ear in response to stimuli. OAEs provide a sensitive measure of the functional integrity of the outer hair cell (OHC). OAEs and ABR are used in hearing assessments of young children and adults and have an important role in the diagnosis of hearing loss. The purpose of this study was investigating the order of carrying out of auditory tests. Fifteen children enrolled in this study with a mean age of about 2.53±0.42 years old. At first, OAE assessments (DPOAE and TEOAE) were perfprmed; then, ABR assessment and finally the OAE measurements were repeated. The results show the amplitude of OAEs was temporally decreased after ABR measurements. A practical outcome of this study is a recommendation for the reversal of the traditional order for carrying out auditory tests, with the OAEs measurements preceding the ABR assessment, thus ensuring that the OAEs responses are unaffected.

Background and Objective: Hyperbilirubinemia is a common neonatal abnormality. Severe hyperbilirubinemia is a risk factor for auditory system injury. Auditory brainstem responses (ABR) are important in early diagnosis of hearing impairments in healthy term infants with elevated bilirubin levels requiring exchange transfusion.Materials and Methods: During a two- year- period (2007 - 2009), in a prospective descriptive analytical study, in Tehran Milad Hospital, 64 (32 female, 32 male), healthy term (> 37 weeks) infants, who required treatment or were treated with phototherapy or received exchange transfusion for elevated bilirubin levels or jaundice, were studied. After obtaining a written consent from their parents, the infants were tested with auditory brain responses and results were analyzed using SPSS 16 software.Results: No significant correlation was found between ABR and age, weight, bilirubin level or ABO blood group. Nineteen out of 64 infants received exchange transfusion. Three out of 19 infants (16%) exhibited abnormal ABR and 16 infants (84%) had normal ABR. There was no significant correlation between exchange transfusions and ABR (P>0.05).Conclusion: The results pointed out that 14% of the infants with elevated bilirubin who required exchange transfusion had abnormal ABR. This indicates that elevated bilirubin levels even without inducing kernicterus should be considered as risk factors for hearing impairments. Further studies are needed on how long these tests may remain abnormal.

Background: In search for a reliable objective test for early evaluation of hearing impainnent, we have tried to compare the results of pure tone audiometry with results of distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) in normal subjects, patients with meniere's disease (MD) and patients with noise induced hearing loss (NIHL).Methods and Materials: Hearing thresholds (HT) of the MD were significantly worse than the nonnal group at all frequencies (p<0.01). HTs of the NlHL group were significantly worse than the nonnal group higher frequencies (p<0.03). MD had significantly worse hearing thresholds than NlHL group at 2000 Hz and lower frequencies (p<0.03). Wave V absolute latency for NlHLL was higher than MD and normal groups (p=0.01 and p=0.002, respectively).Results: Distortion product (DP) for the NlHL and MD was significantly lower than the normal group at all frequencies (except 7270 Hz). A subset of subjects with hearing thresholds of less than 30 dB in all frequencies was selected from the three groups. NlHL subjects (but not MD group) had significantly lower DPOAE levels (p<0.05) in all frequencies (except for 7270Hz) as compared to the normal subjects. Conclusions: The results of this study provide a description of DPOAE results for normal and disease populations and support the concept that DPOAE may be used for early detection of NlHL.

In order to study the early Aptian Oceanic Anoxic Event 1a (OAE 1a), calcareous nannofossils are investigated at the late Barremian-early Aptian sediments of the Garau Formation at south west of the Kabir-Kuh anticline, Qaleh-Darreh section. Ninety species of calcareous nannofossils from 43 genus and 15 families are identified along with marker species like Hayesites irregularis and Eprolithus floralis. Based on index calcareous nannofossil taxa, the studied interval is located between the uppermost part of the CC6/NC5 and the early part of CC7/ NC7A. The first occurrence of H. irregularis, the marker of the Barremian-Aptian boundary, used as an index species between CC6/NC5E and CC7/NC6. Statistical analysis of the calcareous nannofossil assemblages at the studied interval indicate the presence of nannoconid decline at the Barremian-Aptian boundary and early Aptian and nannoconid crisis at CC7a/NC6B biozone. Nannoconid crisis is one of the main markers of the early Aptian OAE 1a that is recorded from different parts of the world at the Tethys and Boreal realms, Atlantic and Pacific oceans at the early Aptian (NC6 biozone). At the current study the early Aptian OAE 1a is recorded from the Garau Formation based on calcareous nannofossil assemblages.

Background and Aims: Hearing loss is one of the most common congenital disorders in newborns and infants. Approximately 1-4 of 1, 000 neonates are born with bilateral profound and permanent congenital hearing loss. Therefore, the diagnosis of hearing loss without performing hearing screening at birth is not possible. Otoacoustic Emission (OAE) is one of the tests to diagnose hearing loss and early intervention in neonates. The aim of the present study was to evaluate neonate hearing screening in Sayad-Shirazi Hospital in Gorgan to identify and early diagnose hearing impairment and to prescribe hearing aids.Materials and Methods: As a cross-sectional study, the investigation was performed on all neonates in Sayad Shirazi Hospital. After completing the questionnaire, the first evaluation (OAE) was performed on all alive infants in the first 48 hours of birth. The neonates were re-evaluated within the second months of birth if they were referred. The neonates with failed responses were referred to perform ABR. Data was analyzed using SPSS (version 22).Results: TEOAE tests were performed on 4453 infants in the first 48 hours of birth. A total of 2138 (48 %) infants were females and 2315 (52 %) were males. About 32% of infants had pass response to OAE and 68% of them had no responses (Refer). The second OAE test was repeated before two months of birth. From among 3024 neonates, 92% had response and 104 neonate had no response. ABR test was performed on 104 infants. Only three neonates had abnormal ABR and hearing loss was identified. Three neonates had hearing loss: parents of one of these neonates were relatives, another neonates suffered from high bilirubin, infection, and prematurity, and the third infant had moderate to severe hearing loss without any reason. Hearing aid was prescribed to these three children and two were referred to a consultant for cochlear implant.Conclusion: According to the results of the current study and similar studies in Iran and other countries, the need to implement a comprehensive plan for neonatal hearing screening and early intervention and early detection of hearing loss is important. This can also reduce the considerable costs that are spent for special education for these children.

Objective: Meningitis is one of the most important causes of sensorineural hearing loss in childhood. Because of the critical situation of patients, proper attention is not usually paid to hearing assessment in meningitis. By early detection and medical intervention at proper time, the retadation of lingual development can be avoided. Material & Methods: The hearing function of 40 children with meningitis was evaluated at 24-72 hours after diagnosis (acute period) and 24 hours before discharging from hospital (recovery period) with auditory brainstem responses (ABR). All patients 7-14 days after discharge underwent thorough investigation by detecting otoacoustic emissions test (OAE). Findings: Using the ABR test, during the acute period, 35 (87.5%) patients had normal hearing and in 5 (12.5%) patients severe to profound sensorineural hearing loss was detected. The same results were obtained during recovery period. OAE test showed normal hearing in 37 (92.5%) patients and impaired cochlear function in 3 (7.5%) patients. Conclusion: Early detection of hearing loss in the acute and recovery period of meningitis can be made by ABR and OAE tests.