Transient Evoked Otoacoustic Emissions Screening Research Articles

Revisiting the transient-evoked otoacoustic emissions passing criteria used for newborn hearing screening

Objective To assess transient-evoked otoacoustic emissions (TEOAE) data from 15 years of a newborn hearing screening program and evaluate how well various criteria separate ears with and without hearing loss. Design Retrospective review of TEOAE data using logistic regression, receiver operating characteristic curves, and cumulative percentage graphs. Study sample: Children with hearing loss who passed TEOAE screening as a newborn were compared to children who failed TEOAE screening and normal hearing children who either passed or failed. Exclusions were applied for acquired hearing loss or auditory neuropathy. Results Ears with hearing loss that passed screening had significantly lower TEOAE response levels compared to ears with normal hearing. Noise levels, test times, and number of sweeps were also lower. Most of these ears had mild hearing loss. Logistic regression results showed that high-frequency TEOAE response level is the best predictor of hearing loss. A multivariate “logit” score calculated from the regression was the best indicator for separating ears with hearing loss from ears with normal hearing. Conclusions TEOAE response levels or an algorithm which incorporates logit scores should be considered as a minimum passing criterion to increase the sensitivity of the TEOAE screening.

Neonatal hearing screening - does failure in TEOAE screening matter when the AABR test is passed?

PurposeNewborns who fail the transient evoked otoacoustic emissions (TEOAE) but pass the automatic auditory brainstem response (AABR) in universal newborn hearing screening (UNHS), frequently have no further diagnostic test or follow-up. The present study aimed to investigate whether hearing loss might be missed by ignoring neonatal TEOAE failure in the presence of normal AABR.MethodsA retrospective analysis was conducted in newborns presenting between 2017 and 2021 to a tertiary referral centre due to failure in the initial UNHS. The main focus was on infants who failed TEOAE tests, but passed AABR screening. The clinical characteristics and audiometric outcomes were analysed and compared with those of other neonates.ResultsAmong 1,095 referred newborns, 253 (23%) failed TEOAE despite passing AABR screening. Of the 253 affected infants, 154 returned for follow-up. At 1-year follow-up, 46 (28%) achieved normal audiometric results. 32 (21%) infants had permanent hearing loss (HL) confirmed by diagnostic ABR, 58 (38%) infants had HL solely due to middle ear effusion (MEE), and for 18 (12%) infants HL was suspected without further differentiation. The majority of permanent HL was mild (78% mild vs. 13% moderate vs. 9% profound). The rate of spontaneous MEE clearance was rather low (29%) leading to early surgical intervention in 36 children. The profile of the risk factors for hearing impairment was similar to that of newborns with failure in both, TEOAE and AABR; however, there was a stronger association between the presence of risk factors and the incidence of HL (relative risk 1.55 vs. 1.06; odds ratio 3.61 vs. 1.80).ConclusionIn newborns, the discordance between a “refer” in TEOAE and a “pass” in AABR screening is associated with a substantial prevalence of hearing impairment at follow-up, especially in the presence of risk factors.

Microcontroller-based acquisition system for evoked otoacoustic emissions: Protocol and methodology

This work presents the development of a signal acquisition and processing system for the fast detection of Transient-Evoked Otoacoustic Emissions (TEOAE). It was built under IEC 60645-6, IEC 62304, and IEC 82304-1 standards. Hardware and firmware specifications based on a Cortex-M7 microcontroller and an ER-10D acquisition probe are presented. A user interface was designed for parameter configuration and monitoring the detection process in a host personal computer. The signal processing chain is presented, and a time–frequency binary-mask approach is proposed to increase the signal-to-noise ratio, leading to a significant decrease in the average detection time. Results obtained with the implemented prototype for two different detection strategies were compared with those from a commercial equipment. Screening tests were performed with eight volunteers and one neonate with normal hearing. On average, the proposed hardware and associated signal processing methods provided a detection time fourteen times faster than the analyzed commercial system. These results are of special interest to developers of TEOAE screening systems.

Implementing hearing screening among children aged 0-59 months at established immunization clinics in Uganda: A multi-center study.

The prevalence of childhood hearing loss (HL) is high in low and middle income countries (LMICs), with many of the affected children facing communication delays and poor opportunities for education. Despite the increased advocacy for childhood hearing screening globally, Uganda has no established childhood hearing screening programs. This study set out to introduce hearing screening services by non-specialist health workers at routine immunization clinics among children aged 0-59 months and describe the prevalence and factors associated with failed hearing screening (HS) in these children. A cross-sectional multi-center study was conducted at immunization clinics at three regional referral hospitals (RRHs). A semi structured questionnaire was used to capture data on socio-demographic, clinical factors and the two stage Transient Evoked Oto-acoustic emissions (TEOAEs) screening performed on children aged 0-59 months. A child that failed two stage screening was considered to have failed HS. Logistic regression was used to calculate odds ratios (OR) for factors associated with failed HS. 1217 children were recruited at three RRHs, with a median age of 2 months (range: 0 to 59), half were male 52% (n=633). Overall 45 children failed two staged TEOAE screening giving a prevalence of failed HS of 3.7%, of these 27 (2.2%) and 18 (1.5%) failed unilaterally and bilaterally respectively. Children of rural residence (aOR=2.18, p=0.027), of low birth weight (aOR=0.42, p=0.045), with relatives having hearing loss (aOR=4.64, p= <0.001), who were admitted in hospital after birth (aOR=3.72, p=0.012) and a history of a childhood suppurative otitis media (aOR=9.53, p=0.015) all had increased odds of failed HS. The prevalence of failed screening is high. Implementation of childhood hearing screening by non-specialist health workers at immunization clinics using TEOAEs is possible and may be a necessary initial step in starting countrywide hearing screening in Uganda.

Auditory assessment of neonates at high risk of hearing impairment admitted to the intensive care unit

Background: Permanent hearing loss is a common neonatal health problem which leads to deleterious effects on language, speech development and academic outcome. Its prevalence is much higher in newborns that need neonatal intensive care admission. Methods: This is a cross-sectional study included 314 neonates admitted to neonatal intensive care unit. The inclusion criteria included neonates with risk factors of hearing loss. They were all evaluated by Transient Evoked Otoacoustic Emissions (TEOAE). Automated auditory brainstem response (AABR) was done at 3 months of age for those who failed TEOAE screening. Results: Out of 314 neonates, 4.5% were diagnosed by permanent hearing loss. No statistical significance was detected between hearing loss and gender (P = 0.61), prematurity (P = 0.529) and birth weight (P = 0.076). The most common risk factor detected was ototoxic drug intake, with aminoglycosides being the most frequent. There was a significant P value between ototoxic medications and hearing loss (P = 0.018). The highest percentage of cases with hearing loss was detected among neonates who received both aminoglycosides and vancomycin. Conclusion: The prevalence of permanent hearing loss among admitted neonates at risk of hearing loss are high.

The Impact of Pass/Refer Criteria in the Use of Otoacoustic Emission Technology for Newborn Hearing Screening.

Purpose The current study aimed to compare the specificity of transient evoked otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) in isolation and in combination, with varying pass/refer criteria for DPOAE technology. Method A longitudinal, repeated-measures design was employed. The current study sample comprised 91 of the initial 325 participants who returned for the repeat screening and diagnostic audiological assessment within a risk-based newborn hearing screening program. Results TEOAE screening had the highest specificity in comparison to DPOAE screening at the initial and repeat screening, irrespective of differences in DPOAE pass/refer criteria. DPOAE screening had a slightly higher specificity, with a three out of six rather than the four out of six frequency pass criteria. Conclusions Pass/refer criteria alone do not influence referral rates and specificity. Instead, consideration of other factors in combination with these criteria is important. More research is required in terms of the sensitivity and specificity of OAE screening technology using repeated-measures and diagnostic audiological evaluation as the gold standard.

Are ABO Blood Groups or Rh Antigen Perinatal Factors Affecting the Pass Rate of Transient Otoacoustic Emissions Screening Tests in Healthy Newborns during the First 48 h of Life?

Most hospitals recommend performing neonatal hearing screening. Transient evoked otoacoustic emission (TEOAE) tests represent an ideal technique for conducting this process. Previous studies have related the influence of ABO blood group and Rhesus antigens (Rh) on the susceptibility to various pathologies. However, available data about the potential relationship between ABO blood groups, Rh, and TEOAE pass rates are sparse. Recently, several authors concluded that O blood group and Rh+ are possible influential factors of TEOAE pass rates. Significantly different TEOAE amplitude response between the four main ABO blood groups were observed among normal-hearing individuals. Moreover, ABO blood groups were discussed as a possible influential factor for the development of noise-induced hearing loss later in life. The aim of this study was to investigate the relationship between ABO blood groups, Rh, and the first TEOAE pass rates in healthy newborns. Data were retrospectively collected from healthy newborns at the maternity ward of F. Borja hospital in Gandia (Spain). Rh and ABO were compared with the results of TEOAE performed within the first 48 h of life. Results: the study group included 2765 newborns. No significant correlation between ABO blood group or Rh and TEOAE pass rates was observed in comparative tables. Conclusion: ABO blood group and Rhesus antigens do not appear to have a significant impact on the pass rate of TEOAE screening in healthy newborns.

Improved transient evoked otoacoustic emission screening test using simple regression model and window optimization

The underlying problem in detection of transient evoked otoacoustic emission (TEOAE) is its extremely low level which is much under the level of noise that appears in the auditory canal. The algorithms based on wavelet transformation (WT) and frequency (e.g. scale) dependent windows are proved to have higher specificity and sensitivity of TEOAE test in comparison to the FFT-based algorithms using single analysis window. In this paper, a new algorithm for TEOAE screening test with improved performances is proposed. It is based on three improvements. The first one is based on simple linear regression model applied to series of signal-to-noise ratio (SNR) estimates and correction of the reproducibility estimate by mean square error criterion. The second one exploits inter-subjects variability of TEOAE latency by selecting the best window position. The third is based on the use of specific window shape developed from approximate of minimum mean square error criterion. The performance of the proposed TEOAE algorithm was tested on real TEOAE measurements embedded in artificial noise as well as on pure noise extracted from TEOAE measurements. The results provided evidence for the superiority of its performance in comparison with two referential algorithms.

Newborn hearing screening in prematurity: fate of screening failures and auditory maturation.

The purpose of this study was to identify delayed auditory maturation and the fate of premature infants who failed the newborn hearing screening (NHS) in neonatal intensive care unit. A total of 1375 neonates underwent NHS using the transient evoked otoacoustic emission (TEOAE) in a tertiary hospital between 2007 and 2010 according to the Joint Committee on Infant Hearing guidelines. In addition, a structured telephone survey was given to caregivers of infants who were lost to follow-up NHS. Auditory steady-state response (ASSR) threshold and the threshold change in diagnostic test failures were analysed. Among the 1375 NICU babies, 344 (25.0%) babies, 111 (9.7%) babies and 64 (4.6%) babies failed to pass the first TEOAE, second TEOAE and diagnostic ASSR, respectively. However, at the age of about 5 years, 12 (0.9%) infants showed permanent hearing loss (PHL). The ASSR threshold improved from 69.0 ± 19.7 dB to 52.9 ± 21.6 dB in <4 months (P < 0.001). Premature infants of <29 weeks of gestational age at birth showed higher referral (P = 0.003) rate at the first OAE test compared to the others, and the difference continued until the last follow-up. The odds ratio for the initial ASSR threshold >67.5 dB for PHL was 9.00 (95% confidence interval, 1.7-46.7). Most of first TEOAE screening failures (91.3%) showed normal hearing and speech development. Hearing levels in premature infants can improve over time, particularly in neonates with initial ASSR threshold <67.5 dB.

An effective compromise between cost and referral rate: A sequential hearing screening protocol using TEOAEs and AABRs for healthy newborns

ObjectiveThis study evaluated the efficacy of a sequential hearing screening protocol using transient evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR) tests in healthy newborns. DesignA TEOAE screening was performed during the first 48–72 h of life. If the infants failed, an AABR test was performed at the same time, and they were referred for a TEOAE rescreening at six weeks old. The results of screening Protocol 1 (only TEOAE) were compared with those of screening Protocol 2 (sequential TEOAE + AABR screenings for the first screening and TEOAE for the rescreening). Study sampleA total of 1062 healthy newborns were enrolled in this research. ResultsFor Protocol 1, the first screening and rescreening referral rates were 11.1% and 2.2%, respectively. In contrast, for Protocol 2, the referral rates were significant lower at 3.8% and 0.9%, respectively. Using the two protocols, six infants were diagnosed with hearing loss (0.57%). ConclusionsAdding simultaneous AABR tests for infants who fail TEOAE testing at the first screening stage can significantly reduce referral rates without increasing misdiagnosis rates. Although this sequential screening process involves slightly more time and has a higher cost than TEOAE alone, its greater accuracy compensates for this difference.

Evidence for a Right-Ear Advantage in Newborn Hearing Screening Results.

The aim of the present study was to investigate the effect of ear asymmetry, order of testing, and gender on transient-evoked otoacoustic emission (TEOAE) pass rates and response levels in newborn hearing screening. The screening results of 879 newborns, of whom 387 (study group) passed screening successfully in only one ear in the first TEOAE screening, but passed screening successfully in both ears thereafter, and 492 (control group) who passed screening successfully in both ears in the first TEOAE, were retrospectively examined for pass rates and TEOAE characteristics. Results indicated a right-ear advantage, as manifested by significantly higher pass rates in the right ear (61% and 39% for right and left ears, respectively) in the study group, and in 1.75 dB greater TEOAE response amplitudes in the control group. The right-ear advantage was enhanced when the first tested ear was the right ear (76%). When the left ear was tested first, pass rates were comparable in both ears. The right-ear advantage in pass rates was similar in females versus males, but manifested in 1.5 dB higher response amplitudes in females compared with males, regardless of the tested ear and order of testing in both study and control groups. The study provides further evidence for the functional lateralization of the auditory system at the cochlear level already apparent soon after birth in both males and females. While order of testing plays a significant role in the asymmetry in pass rates, the innate right-ear advantage seems to be a more dominant contributor.

Hearing impairment and its risk factors by newborn screening in north-western India.

BackgroundTo screen the newborn by Transient evoked Otoacoustic emission and to assess the incidence of hearing damage and associated risk factors.MethodThis longitudinal prospective observational study was conducted at a tertiary care hospital in India. A total of 415 babies were included in the study. All the newborns were evaluated with Transient evoked Otoacoustic emission (TEOAE) which was done by age of 1–3 days. Auditory brain stem response audiometry (AABR) was performed at the age of three months for confirming the hearing loss in the neonates those who failed the TEOAE screening. For infants proven to have significant hearing loss in one or both ears, were denoted to an ear, nose, and throat specialist for further evaluation & rehabilitation.ResultsOut of total 415 babies included in the study, 22 neonates showed abnormal TEOAE examination. Out of these 22 neonates, hearing loss was confirmed in 18 (82 %) subjects. by AABR. The following antenatal and post-natal risk factors were associated with hearing loss: ante-partum bleeding, history of maternal blood transfusion, fetal distress, prematurity, severe birth asphyxia, NICU admission for more than 24 h and Apgar score less than five at 5 min.ConclusionLate identification of hearing loss presents a substantial public health burden. Early recognition and intervention prior to 6 months of age has a significant positive impact on development. A high incidence of hearing impairment seen in our study neonatal population warrants the urgent implementation of universal hearing screening of all the newborn infants in India. NICU infants admitted for more than 24 h are to have an auditory brainstem response (AABR) included as part of their screening so that neural hearing loss will not be missed.

When should automatic Auditory Brainstem Response test be used for newborn hearing screening?

The aim of this study was to investigate the referral rate and when automatic Auditory Brainstem Response (aABR) should be used for newborn hearing screening. The present study enrolled 2933 healthy full-term infants and 176 infants with perinatal risk factors. Hearing screening using Transient Evoked Otoacoustic Emissions (TEOAEs) was performed in newborns for the first time 5 days after birth except perinatal risk factors infants. The TEOAE was repeated to neonates failing to pass at the 15th day after birth. Neonates failing to pass the second TEOAE, repeated the test again at the 30th day after birth. Neonates failing to pass the third TEOAE were referred for the second stage screening using aABR. In addition, neonates with risk factors were tested with aABR directly. In this research, 85 (2.9%) infants who could not pass the TEOAE and 176 infants exposed to perinatal risk factors, underwent the aABR test. In the aABR, 14 (7.9%) of 176 infants exposed to perinatal risk factors and 10 (11.7%) of 85 infants who could not pass the TEOAE failed to pass. As a result, hearing loss was detected in only 10 (0.34%) of 2933 healthy full-term infants. TEOAE should be performed at least twice in healthy full-term infants before aABR, because aABR is to be performed by specially trained personnel and takes a long time. In view of these results, it is our opinion that infants without perinatal risk factors should undergo TEOAE screening test and infants who did not pass control screening tests and have perinatal risk factors should absolutely undergo aABR test. But it should be remembered that TEOAE can cause a problem to miss auditory neuropathy in infants without perinatal risk factors.

Transient evoked oto-acoustic emission screening in newborns in Bogotá, Colombia: A retrospective study

ObjectiveThe aim of this study was to investigate the characteristics and performance of transient evoked oto-acoustic emission (TEOAE) hearing screening in newborns in Colombia, and analyze all possible variables and factors affecting the results. Materials and methodsAn observational, descriptive and retrospective study with bivariate analysis was performed. The study population consisted of 56,822 newborns evaluated at the private institution, PREGEN. TEOAE testing was carried out as a pediatric hearing screening test from December 2003 to March 2012. The database from PREGEN was revised, and the protocol for evaluation included the same screening test performed twice. Demographic characteristics were recorded and the newborn's background was evaluated. Basic statistics of the qualitative and quantitative variables, and statistical analysis were obtained using the chi-square test. ResultsOf the 56,822 records examined, 0.28% were classed as abnormal, which corresponded to a prevalence of 1 in 350. In the screened newborns, 0.08% had a major abnormality or other clinical condition diagnosed, and 0.29% reported a family history of hearing loss. A prevalence of 6.7 in 10,000 was obtained for microtia, which is similar to the 6.4 in 10,000 previously reported in Colombia (database of the Latin–American Collaborative Study of Congenital Malformations – ECLAMC). Statistical analysis demonstrated an association between presenting with a major anomaly and a higher frequency of abnormal results on both TEOAE tests. ConclusionsNewborns in Colombia do not currently undergo screening for the early detection of hearing impairment. The results from this study suggest TEOAE screening tests, when performed twice, are able to detect hearing abnormalities in newborns. This highlights the need to improve the long-term evaluation and monitoring of patients in Colombia through diagnostic tests, and to provide tests that are both sensitive and specific. Furthermore, the use of TEOAE screening is justified by the favorable cost: benefit ratio demonstrated in many countries worldwide.

Analysis of Hearing Screening Test Findings of 11,575 Newborns in Turkey

Objectives: Review the newborn hearing screening test data performed at Corlu State Hospital, Turkey, during the last 3 years. Methods: A total of 11575 newborns that were either born in this hospital or referred from other healthcare centers between September 2009 and September 2012 were included. TEOAE (Transient Evoked Otoacoustic Emissions) test and AABR (Automated Auditory Brainstem Response) were used as screening tests. After the newborn failed the initial TEOAE test, the test was repeated after 15 days. If the same result was obtained at the second test, the newborns were referred for ear, nose, and throat (ENT) examination. TEOAE and AABR screening tests were performed as the third stage evaluation. Results: Out of 11575 newborns, 593 (5.12%) had failed the test and were referred for ENT examination and further evaluation. Out of these 593 neonates, 474 (79.93%) passed the second step test at the referral center. 106 (17.87%) did not show up again, so we did not get any information about them. Unfortunately, bilateral and unilateral sensory neural hearing impairment was detected in 12 and 3 babies, respectively. Seven of these babies had risk factors such as family history of hearing loss and consanguineous marriages. Conclusions: Newborn hearing screening and early diagnosis are an problems in our field. The final hearing impairment ratio of our study was parallel to general statistics, but our false positive ratio seemed to be higher than that of other centers. It is important to do all tests at the same center concomitantly in order to decrease the false negative ratio.

Screening of delayed-onset hearing loss in preschool children in the mid-south of China

Objective: Newborn hearing screening has been successfully implemented worldwide to improve the detection of hearing loss. However, delayed-onset hearing loss subsequent to newborn hearing screening remains a concern. This study aimed to investigate the prevalence of delayed-onset hearing loss in preschool children who previously passed newborn hearing screening in Hubei Province in mid-south China. Design: Preschool children were screened by transient evoked otoacoustic emission (TEOAE) for delayed-onset hearing loss. Children referred after the TEOAE screening were assessed audiologically. Study sample: Between March 2010 and September 2011, 28 546 preschool children (4.86 ± 1.67 years old), who had passed newborn hearing screening were targeted for screening from four cities in Hubei Province, China. Results: During the study period, 540 children (1.89%) were referred for audiologic assessment and 22 (0.77/1000) of them had permanent delayed-onset hearing loss, including 8 (0.28/1000) with bilateral moderate hearing loss, 10 (0.35/1000) with mild bilateral hearing loss, 2 (0.07/1000) with unilateral moderate hearing loss, and 2 (0.07/1000) with unilateral mild hearing loss. Conclusions: Despite the success of newborn hearing screening, the provision of hearing screening in preschool remains essential for identifying delayed-onset hearing loss.

Frequency of Profound Congenital Hearing Loss in Healthy Newborn Infants in Fars Province

Introduction Deafness is one of the most important sensory disturbances at birth. Hearing loss can affect the development of speaking and learning during life. Early diagnosis and intervention improve language outcome. The current study aimed to determine the frequency of profound congenital hearing loss in healthy newborn infants in Fars province. Methods In a multicenter prospective study, from August 2010 to August 2011, 12573 newborns were screened for hearing loss prior to discharge from the wellborn nursery at nine teaching and private hospitals in Fars province. A three-stage hearing screening protocol using transient evoked otoacoustic emissions (TEOAE) screening with referral for diagnostic second TEOAE and auditory brainstem evoked response (ABER) assessment was employed. All neonates with abnormal initial TEOAE screening, followed with phone call for language outcome after one year. Newborns with hospital admission or drug administration excluded from the study.Results The overall pass rate in the initial screening was 91.8%, thus 1019(8.1/1000) neonates referred for diagnostic audiological assessments. Out of 1019 infants scheduled for follow-up study, only 619 neonates returned. Using follow-up letters and phone calls, it was managed to improve the response rate for language outcome after one year. Two infants were identified with profound bilateral congenital hearing impairment. These infants were immediately referred for cochlear implantation.Conclusion Findings of the current study showed that the frequency of profound congenital hearing loss is 0.159/1000 normal newborn infants in Fars province. The initial TEOAE has high false positive that may be due to occlusion of external ear canal by vernix in the early postnatal period.

Results of a 1‐year government‐funded newborn hearing screening program in Taiwan

To establish an ideal operative procedure of universal newborn hearing screening and to investigate whether a government-funded program increases compliance with such screening. Individual cohort study. Of the 3,373 neonates born at the Taipei City Hospital during the period August 2009 to July 2010, there were 3,361 who received hearing screening with automatic auditory brainstem response (AABR) 24 to 36 hours after birth. The cost of each procedure (US $16.70) was covered by the Taipei City Health Bureau. The control group comprised 6,582 neonates born at the same hospital during the period January 2003 to December 2004, of whom 5,749 had been screened with transient-evoked otoacoustic emission (TEOAE). The cost of each procedure (US $26.70) was paid by the parents of each newborn. The incidence of bilateral moderate to severe hearing impairment was 0.06% (two out of 3,361) and 0.10% (six out of 5,749) in the study and the control group, respectively. The incidence of unilateral hearing impairment was 0.09% (three out of 3,361) and 0.19% (11 out of 5,749) respectively. The coverage rate of the study was significantly higher than that of the control group (99.64% vs. 87.34%, P < .001). A significant decrease of the referral rate was achieved in the study group when compared with the control group (0.95% vs. 2.82%, P < .001). The follow-up rate of the study group was significantly higher than that of the control group (100.00% vs. 40.74%, P < .001). The government-funded AABR program resulted in markedly better parental compliance with newborn hearing screening than the self-pay TEOAE screening program. 2b.

Risk factors associated with hearing loss in infants: An analysis of 5282 referred neonates

Objective The aim of our study was to evaluate the frequency of risk factors and their influence on – the distribution and manifestation of – hearing loss in infants. The study was conducted at the Department of Laryngology in the Upper Silesian Center for Child Health in Katowice (Poland), as part of the Polish National Universal Neonatal Hearing Screening, conducted from 2003 to 2009. Materials and methods The selected population included every newborn that twice tested positive on the transient evoked otoacoustic emission (TEOAE) screening test, as well as all neonates with one or more risk factors as defined by the Joint Committee of Infant Hearing in 2000 (JCIH). The following procedures were used with each neonate: otolaryngological examination (with otoscopy), tympanometry, automated otoacoustic emission (AOAE), and auditory brainstem response (ABR). A total of 5282 infants were examined. Subjects were categorized into two groups: the first group consisted of 2986 (56.53%) neonates with risk factors of hearing loss, while the second group included 2296 (43.47%) neonates without any known risk factors, but who twice tested positive on the TEOAE screening. Results Among all infants examined (5282), sensorineural hearing loss (SNHL) was identified in 240 cases (4.54%), and conductive hearing loss (CHL) in 40 cases (0.76%), while normal hearing (NH) appeared in 5002 cases (94.70%). In the first group, SNHL was identified in 128 neonates (4.29%), and CHL in 28 (0.94%), while NH appeared in 2830 (94.78%). The largest percentage of SNHL (15.52%) appeared in children with identified or suspected syndromes associated with hearing loss. The next highest frequency of SNHL was comprised of children subjected to mechanical ventilation for a period in excess of 5 days (11.45%). Only a small percentage (2.86%) of SNHL appeared to be due to the use of ototoxic medications, despite the fact that this factor is the most prevalent (33.13%) of all analyzed risk factors of hearing impairment. After ototoxic medications, the frequencies of risk factors are as follows: premature birth (16.21%); low birth weight (12.04%); intensive care in excess of 7 days (10.64%). Furthermore, as the number of coexisting risk factors increases, the probability of SNHL in infants is seen to also increase. For children with one to four coexisting risk factors, the probability of SNHL ranges from 3.15% to 5.56%; for five or more risk factors the probability nearly doubles. Conclusion Our results indicate that syndromes associated with hearing loss and mechanical ventilation for more than 5 days were statistically significant risk factors in the occurrence of hearing loss. The most common risk factors are ototoxic medications, premature birth, low birth weight, and intensive care in excess of 7 days. As the number of risk factors an infant is exposed to grows, the probability of hearing impairment increases. The large percentage of children with sensorineural hearing loss in the absence of any known risk factors demonstrates the necessity of hearing examinations in all neonates.

Ambient noise levels and infant hearing screening programs in developing countries: An observational report

Considering that current newborn/infant hearing screening (NHS) instruments were designed primarily for use in developed countries, this study set out to ascertain the potential effects of higher ambient noise levels on transient-evoked otoacoustic emissions (TEOAE) in sub-Saharan Africa. Data was drawn from two hospital-based and community-based NHS programs in Lagos, Nigeria, with a total screened population of 11 893 infants. Two automated TEOAE screening devices—Echo-Screen and ECHOCHECK—were available for this study. Ambient noise levels ranged from 61.0–90.5 dBA in the hospital wards and 55.6–82.5 dBA in the community health centers. One TEOAE model could not be activated at the prevailing noise levels. No significant pattern was observed in average noise levels and overall TEOAE referrals across all screening sites. However, the false-positive rates ranged from 1.4–13.8%. This study suggests that valid TEOAE screening is attainable in the Negroid race in settings with ambient noise levels up to 68 dBA but the associated high false-positive rates may necessitate additional screening with auditory brainstem response to achieve acceptable overall referral rates for timely diagnostic evaluation.SumarioConsiderando que los instrumentos para tamiz auditivo neonatal/infantil (NHS) fueron diseñados primordialmente para su uso en países desarrollados, este estudio se propone establecer los efectos potenciales de altos niveles de ruido ambiental en las emisiones otoacústicas por productos de distorsión (TEOAE) en el Africa sub-sahariana. Los datos se obtuvieron de dos programas de NHS, con base hospitalaria y con base comunitaria de Lagos, Nigeria, con una población tamizada total de 11,893 infantes. Para este estudio estuvieron disponibles dos equipos de TEOAE – Echo-Screen y ECHOCHECK. El ruido ambiente varió de 61.0 a 90.5dBA en las salas hospitalarias y de 55.6 a 82.5 dBA en los centros de salud comunitarios. No fue posible activar un modelo de TEOAE con los niveles de ruido prevalecientes. No se observó ningún patrón de ruido promedio ni de las TEOAE que de refirieron en todos los sitios de tamiz. Sin embargo, las tasas de falsos positivos variaron de 1.4 a 13.8%. Este estudio sugiere que el tamiz con TEOAE es asequible en la raza negra en lugares con ruido ambiente de niveles hasta 68dBA pero por el nivel de falsos positivos asociado se podría requerir tamiz adicional con respuestas auditivas de tallo cerebral para alcanzar niveles aceptables de referencia para evaluación diagnóstica.