Automated Auditory Brainstem Response Research Articles

Diagnostic accuracy of CE Chirp

ObjectiveThere has been an increase in the use of the CE-Chirp stimulus in automated auditory brainstem response (AABR) equipment for neonatal hearing screening. The purpose of this study is to evaluate the diagnostic accuracy of the LS CE-Chirp-evoked auditory brainstem response (ABR) compared to the click-evoked ABR for the identification of different degrees and configurations of sensorineural (SNHL) hearing loss. Method49 ears with mild to moderate SNHL were assessed: 16 ears with rising SNHL and 33 ears with sloping high frequency SNHL. Behavioural pure tone thresholds were obtained at 125–8000 Hz and ABR thresholds were measured using the click and LS CE-Chirp stimuli respectively. Click- and LS CE-Chirp-evoked thresholds were compared with each other and with behavioural pure tone average at 500, 1000, 2000 Hz (PTA), high frequency average at 2000, 4000, 8000 Hz (HFA) and low frequency average at 250, 500, 1000 Hz (LFA). Diagnostic accuracy of the two ABR stimuli was also compared by using ROC curves. ResultsDifferences between click- and LS CE Chirp-evoked ABR, and behavioural thresholds were not statistically significant (p > 0.05). The highest significant correlations for ABR using clicks to behavioural thresholds was found at 2000 and 4000 Hz, whereas, the highest correlation for LS CE-Chirp ABRs to behavioural thresholds was found at 1000, 2000 and 4000 Hz (r > 0.7, p < 0.001). A very strong, positive correlation was found between both click (r = 0.805, p < 0.001) and LS CE-Chirp (r = 0.825, p < 0.001) and the behavioural PTA. LS CE-Chirp ABR thresholds were closer to mid and low frequency thresholds than the click ABR while the click-evoked thresholds were in closer proximity to HFA. Sensitivity and specificity and false negative rates were identical. Diagnostic accuracy of the LS CE-Chirp ABR was equal to or better than click for low (area under the curve (AUC) = 0.83), mid (AUC = 0.89) and high frequency hearing losses (AUC = 0.73). However, scatterplots indicated more frequent underestimation of behavioural pure tone thresholds at mid and high frequencies with the LS CE-Chirp than for the click ABR. ConclusionThe diagnostic accuracy of the LS CE Chirp-evoked ABR is equivalent or better than the click-evoked ABR. The importance of ongoing surveillance and consideration of ABR screening protocols is consequently emphasized.

Auditory Brainstem Evoked Response Patterns in the Neonatal Intensive Care Unit.

Delayed maturation of auditory brainstem pathway in neonates admitted to the neonatal intensive care unit (NICU) may lead to misdiagnosis of children with normal peripheral hearing and inappropriate use of amplification devices. The aim of this study is to determine the pattern of auditory brain stem response in neonates admitted to the NICU for proper hearing assessment in this high-risk population. This prospective study was conducted on 1,469 infants who were admitted to the NICU, of which 1,423 had one or more risk factors for permanent congenital hearing loss and were screened with automated auditory brain stem response (AABR). A total of 60 infants were referred for diagnostic ABR analysis after failure on AABR screening. The control group comprised 60 well-baby nursery neonates with no risk factors for PCHL. Mean values of absolute latencies of waves III and V; interpeak latencies I-III, III-V, and I-V; amplitude of waves I, and V; and I/V amplitude ratio at 90 dBnHL measured for the right and left ears at 1 and 3 months of age show significant difference in NICU neonates compared with controls (p < 0.05). All the diagnostic ABR measurements significantly improved at the age of 3 months (p < 0.001) except wave I absolute latency of both groups (p > 0.05). Significant correlations were found between ABR readings at the age of 1 and 3 months and the gestational age of the NICU neonates (p < 0.05). Diagnostic ABR findings in NICU neonates suggested delayed maturation of the auditory brainstem pathway with a great impact of gestational age on this maturation. Auditory maturational changes were observed at 3 months of age of patient and control groups.

Seropositivity of Anti-Rubella Antibodies as A Marker for Rubella Infection in Infants at High Risk of Congenital Deafness

Hearing loss in newborns or congenital deafness can be caused by the development of several parts of the auditorysystem. Congenital deafness is often associated with infections, such as Toxoplasmosis, Rubella, Cytomegalovirus (CMV),and Herpes (TORCH). Deafness is very difficult to be early detected. Therefore, simple but fast methods are needed. Earlydetection is based on the Newborn Hearing Screening (NHS) program. Otoacoustic Emission (OAE) and AutomatedAuditory Brainstem Response (AABR) checks are raw materials for early detection. Congenital deafness often occurs withpregnancy infections with viruses such as Rubella. Rubella infection during pregnancy, especially during the first trimester,often causes Congenital Rubella Syndrome (CRS). Rubella infection often occurs with other causes, such as Toxoplasma,CMV, and Herpes. A Serological test can be used as one of the diagnostics of this infection. This study used single RubellaIgG and IgM antibodies and double antibodies test as a marker for the infection. The authors wanted to correlate theserological examination of this infection with the auditory function. Rubella infection was detected with single serologicalanti-Rubella IgG and IgM and double multiple Rubella and TORCH serological tests. Also, the auditory function wasassessed using the OAE and AABR test in this research. The result showed 35 (77.7%) patients with positive Rubellaserological tests among 45 NICU patients at Dr. Soetomo Hospital. There were number of patients was 12 (34.2%) patientswith a single positive serological test and 23 (65.7%) patients with positive multiple TORCH serological tests. The number ofpatients with Rubella negative infection was 10 (22.2%). There were 11 (31.4%) patients of positive Rubella infections withpositive hearing loss and 24 (68.6%) patients with negative hearing loss. From the results of the study, 35 patients were athigh risk of disturbance and the statistical analysis showed that there were no significant serological differences in Rubellapositive with hearing loss (p=0.087). Hearing loss in NICU infants has a high risk of factors causing Rubella infection andother related causes. In most Rubella positive serological tests IgG was found, which can be due to maternal factors.Serology tests need to be repeated for confirmation under the surveillance program. How to follow-up the patients anddefine the next laboratory test after six months remain a great challenge. The efforts need to be strengthened in surveillanceprograms.

Evaluation of Universal Newborn Hearing Screening and follow-up

Universal newborn hearing screening (UNHS) was established in Germany in 2009. Even compliance was tested in early studies, there is little knowledge regarding the follow-up examination of children with suspected hearing disorder. A retrospective evaluation was performed in 570cases of children who failed newborn hearing screening for the years between 2009-2016. Hearing deficiency was defined as having a hearing threshold ≥ 35 dB. Compliance with national guidelines was checked. Every child received brainstem evoked response audiometry (BERA). Permanent hearing disorder was found in 24 %, of whom about half (51 %) had an inner ear hearing loss (of these in 73 % bilateral). Only 27 % of high risk children born in peripheral hospitals were tested immediately by the envisaged automated auditory brainstem response (AABR) method. They often presented tardy, leading to a delayed diagnosis and therapy. Children tracked by the Bavarian health office presented little earlier but had less cases who were lost to follow-up. In 93 % a diagnosis was made during first examination and therapy (e. g. prescription of hearing aids) initiated on average within four months age. The rate of deafness corresponded with national averages. The quality of primary screenings is crucial in revealing problems and avoiding delay in dealing with them.

Outcomes of regional-based newborn hearing screening for 35,461 newborns for 5 years in Akita, Japan

ObjectivesNewborn hearing screening (NHS) has been actively performed since 2001 in Akita, Japan. The NHS coverage rate has increased yearly, and performance has been consistently >90% since 2012. The purpose of this study was to summarize NHS outcomes in the Akita prefecture of Japan and to obtain new insights for from our summarized data for the future. MethodsA total of 35,461 newborns in hospitals and clinics where hearing screening was performed in Akita from 2012 to 2016 were included. The outcome data of NHS were collected for analysis. ResultsThe overall screening coverage rate for hearing loss was 94.7%. Of the screened infants, 0.53% received a referral on the 2-stage automated auditory brainstem response (ABR), and 80.4% of referred infants had a check-up at the hospital to receive a diagnostic hearing examination. Finally, the prevalence of bilateral congenital hearing loss was 0.14%, that of bilateral moderate to profound hearing loss was 0.12%, and that of unilateral congenital hearing loss was 0.10%. Furthermore, the average consultation period in infants with risk factors was significantly later than that in infants without risk factors (p = 0.0015). Follow-up for infants diagnosed with normal hearing after diagnostic hearing examination revealed that 4.7% suffered bilateral moderate to profound hearing loss later. This percentage is significantly higher than that of the general group (p < 0.001). ConclusionThe prevalence of bilateral congenital hearing loss was 0.14% in Akita and 0.12% of infants were diagnosed with bilateral moderate to severe hearing loss. Medical personnel should be enlightened regarding the importance of performing hearing diagnostic examinations until 3 months of age. Even if infants were diagnosed with normal hearing after a diagnostic examination, we strongly suggest continuing follow-up until they are able to perform pure tone audiometry with accuracy.

Determining concordance and cost impact of otoacoustic emission and automated auditory brainstem response in newborn hearing screening in a tertiary hospital

ObjectiveThis study compared otoacoustic emission (OAE) and automated auditory brainstem response (AABR) in terms of concordance and cost impact for newborn hearing screening (NBHS) in the Philippine setting. MethodsThis was a prospective observational study to assess concordance between OAE and AABR involving 253 infants. Each infant underwent OAE and AABR testing. Infants who passed both tests were not required to follow up for additional testing. Infants who failed in any test were scheduled for repeat screening and diagnostic ABR after 1 month. Concordance was computed using B-statistic. For cost analysis4 scenarios were compared to 1-step both tests scenario: (1) OAE alone, (2) AABR alone, (3) 2-step OAE, and (4) 2-step AABR in terms of number of infants with hearing loss (HL) detected, cost of diagnosis, and economic loss from lack of treatment. ResultsThere was high concordance between OAE and AABR (B-statistic = 0.8). AABR had a higher refer rate (18.58%) than OAE (10.27%) but higher number of detected babies with HL. Cost analysis favored an AABR alone scenario while the 2-step OAE protocol fared poorly. ConclusionA change from 2-step OAE to AABR alone is worth considering in our institution.

Concurrent Hearing and Genetic Screening of 180,469 Neonates with Follow-up in Beijing, China

Concurrent hearing and genetic screening of newborns is expected to play important roles not only in early detection and diagnosis of congenital deafness, which triggers intervention, but also in predicting late-onset and progressive hearing loss and identifying individuals who are at risk of drug-induced HL. Concurrent hearing and genetic screening in the whole newborn population in Beijing was launched in January 2012. This study included 180,469 infants born in Beijing between April 2013 and March 2014, with last follow-up on February 24, 2018. Hearing screening was performed using transiently evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR). For genetic testing, dried blood spots were collected and nine variants in four genes, GJB2, SLC26A4, mtDNA 12S rRNA, and GJB3, were screened using a DNA microarray platform. Of the 180,469 infants, 1,915 (1.061%) were referred bilaterally or unilaterally for hearing screening; 8,136 (4.508%) were positive for genetic screening (heterozygote, homozygote, or compound heterozygote and mtDNA homoplasmy or heteroplasmy), among whom 7,896 (4.375%) passed hearing screening. Forty (0.022%) infants carried two variants in GJB2 or SLC26A4 (homozygote or compound heterozygote) and 10 of those infants passed newborn hearing screening. In total, 409 (0.227%) infants carried the mtDNA 12S rRNA variant (m.1555A>G or m.1494C>T), and 405 of them passed newborn hearing screening. In this cohort study, 25% of infants with pathogenic combinations of GJB2 or SLC26A4 variants and 99% of infants with an m.1555A>G or m.1494C>T variant passed routine newborn hearing screening, indicating that concurrent screening provides a more comprehensive approach for management of congenital deafness and prevention of ototoxicity.

Detección de la infección por citomegalovirus congénito en neonatos que no pasan el cribado auditivo universal.

Introducción: Dada la importancia del inicio temprano de un tratamiento antiviral en los neonatos con hipoacusia neurosensorial secundaria a infección congénita por citomegalovirus (CMVc), presentamos un protocolo de diagnóstico precoz del CMVc en función del resultado del cribado auditivo neonatal universal con potenciales evocados auditivos automatizados (PEATC-A). Material y métodos: Partiendo del conocimiento actual que aporta la literatura, elaboramos un algoritmo de actuación consensuado entre los coordinadores del Programa de Detección Precoz de la Hipoacusia Infantil en la Comunidad de Castilla y León (España). Resultados: Si la primera prueba de PEATC-A en el neonato es un no pasa de uno o ambos oídos, solicitamos en el plazo de 15 días la identificación del genoma viral mediante PCR en una muestra de orina. La confirmación posterior de hipoacusia neurosensorial uni o bilateral, permitirá el inicio del tratamiento antiviral, antes del primer mes de vida. Discusión: Si bien el cribado universal del CMVc haría posible el seguimiento de todos los neonatos infectados, detectando más precozmente los casos de hipoacusia tardía/progresiva; ante la presencia de una hipoacusia neurosensorial de causa desconocida, a partir de las dos semanas de vida posnatal, se debe intentar descartar una infección por CMVc, aunque en estas condiciones resulta más complicado. Conclusión: La incorporación del diagnóstico del CMVc en el programa de cribado auditivo neonatal, permitirá la detección precoz de algunos niños con infección congénita, pudiéndoles mejorar su calidad de vida.

Neonatal hearing test results in the Çukurova region

Objective: In this article, we aimed to present the neonatal hearing screening protocol and test results in healthy neonates in Adana City Training and Research Hospital, Adana. Method: A total of 2022 healthy newborns were scanned between November 2018 and February 2019 in our hospital with a three-stage screening protocol. Initial transient evoked otoacoustic emissions (TEOAE), followed by a second stage transient evoked otoacoustic emission and third stage automated auditory brainstem response (A-ABR) were used. If there was a referral with these two methods, clinical BERA was used. High risk newborns were defined. Results: In total, of the 2022 infants included in the study, hearing loss was detected in 34 newborns and the frequency of congenital hearing loss was 1.7%. According to our results, hyperbilirubinemia was more common in infants with hearing loss. Conclusion: Performing hearing screening tests in all newborns, raising public awareness on this issue, and legal follow-up are very important.

High-frequency otoacoustic emissions in universal newborn hearing screening

ObjectiveDistortion-product otoacoustic emissions (DPOAEs) are currently used in many newborn hearing screening programs as the initial hearing test, typically testing frequencies between 1 and 4 or 6 kHz, but they have been associated with high false-positive rates. The objective was to investigate the possible benefit of high-frequency DPOAEs for reducing false-positive rates. Methods255 healthy newborns (138 males and 117 females) undergoing conventional hearing screening based on DPOAE and automated auditory brainstem response (AABR) testing were recruited. High-frequency DPOAE amplitudes, noise floors and signal-to-noise ratios (SNRs) were measured for f2 frequencies up to 12 kHz. ResultsOf the 255 newborns who participated in this study, 23 (9%) failed the conventional DPOAE test but passed the AABR test, and 8 (3%) failed both tests. For an SNR threshold of 6 dB, high-frequency DPOAE tests at f2 = 4, 6, 8 and 10 kHz resulted in a reduction in the false-positive rate from 9% to 0.4%, or to zero if only three of the four frequencies were required to exceed the threshold. SNRs were lower in newborns with birth weights greater than 4000 g; lower at 2 kHz in newborns with a gestational age of 41 weeks; slightly higher in vaginally-delivered newborns; and higher at 2 kHz with increasing age in the group that failed the conventional DPOAE test but passed AABR. ConclusionHigh-frequency DPOAEs resulted in a reduction in the DPOAE failure rate and the false-positive rate. These findings may be helpful in universal newborn hearing screening programs.

Risk factors of hearing defects and their relationship to the outcome of hearing screening among neonates

Background: Increased exposure to risk factors of hearing loss leads to a high susceptibility to deafness&#x0D; among neonates admitted to neonatal care units in developing countries.&#x0D; Objective: This article aims to study the prevalence of risk factors for neonatal hearing defect and determine their effect on the result of transient evoked otoacoustic emissions hearing test ( TEOAE). Methods: A longitudinal study was carried out for a period of one year from 1st October, 2016 to 30 th September, 2017 in the CWTH, Medical city, Baghdad, Iraq Demographic characteristics and certain risk factors were recorded for screened neonates. TEOAE test was done and if they failed to pass two steps, they were referred to&#x0D; autom ated auditory brainstem - response (AABR).&#x0D; Results: Out of 400 neonates, 342 (85.5%) passed from step 1TEOAE, while 58 (14.5%) were referred to step 2. From 58, 26 (44.8%) have passed step 2 and 32 (55.2%) not pass step 2 and were referred to AABR. From those 32 neonates with suspected hearing defect, NICU stay &gt;7 days, ototoxic drugs &gt;7days, use of ventilator &gt;7 days, birth weight &lt;1500gm, and craniofacial malformations were the main risk factors for hearing defects occurring in (90.6%), (90.6%), (59.4%), (40.6%), and (21.9%) respectively. &#x0D; Conclusions: Low birth weight , long intensive care stay, mechanical ventilation, drugs ototoxicity and&#x0D; craniofacial malformation of neonates are the main risk factors for failed TEOAE test

Assessing and monitoring the impact of the national newborn hearing screening program in Israel

BackgroundThe Israeli Newborn Hearing Screening Program (NHSP) began operating nationally in January 2010. The program includes the Otoacoustic Emissions (OAE) test for all newborns and Automated Auditory Brainstem Response (A-ABR) test for failed OAE and infants at risk for auditory neuropathy spectrum disorders. NHSP targets are diagnosis of hearing impairment by age three months and initiation of habilitation by six months.Objectives(1) Review NHSP coverage; (2) Assess NHSP impact on age at diagnosis for hearing impairment and age at initiation of habilitation; (3) Identify contributing factors and barriers to NHSP success.Methods(1) Analysis of screening coverage and referral rates for the NHSP; (2) Analysis of demographic data, results of coverage, age at diagnosis and initiation of habilitation for hearing impaired infants pre-implementation and post-implementation of NHSP from 10 habilitation centers; (3) Telephone interviews with parents whose infants failed the screening and were referred for further testing.ResultsThe NHSP coverage was 98.7% (95.1 to 100%) for approximately 179,000 live births per year for 2014–2016 and average referral rates were under 3%. After three years of program implementation, median age at diagnosis was 3.7 months compared to 9.5 months prior to NHSP. The median age at initiation of habilitation after three years of NHSP was 9.4 months compared to 19.0 prior to NHSP. Parents (84% of 483 sampled) with infants aged 4–6 months participated in the telephone survey. While 84% of parents reported receiving a verbal explanation of the screening results, more than half of the parents reported not receiving written material. Parental report of understanding the test results and a heightened level of concern over the failed screen were associated with timely follow-up.ConclusionsThe findings indicate high screening coverage. The program reduced ages at diagnosis and initiation of habilitation for hearing impaired infants. Further steps needed to streamline the NHSP are improving communication among caregivers to parents to reduce anxiety; increasing efficiency in transferring information between service providers using advanced technology while ensuring continuum of care; reducing wait time for follow-up testing in order to meet program objectives. Establishment of a routine monitoring system is underway.

Comparison of distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (AABR) for neonatal hearing screening in a hospital with high delivery rate

IntroductionCongenital hearing loss is one of the commonest congenital anomalies. Neonatal hearing screening aims to detect congenital hearing loss early and provide prompt intervention for better speech and language development. The two recommended methods for neonatal hearing screening are otoacoustic emission (OAE) and automated auditory brainstem response (AABR). ObjectiveTo study the effectiveness of distortion product otoacoustic emission (DPOAE) and automated auditory brainstem response (AABR) as first screening tool among non-risk newborns in a hospital with high delivery rate. MethodA total of 722 non-risk newborns (1444 ears) were screened with both DPOAE and AABR prior to discharge within one month. Babies who failed AABR were rescreened with AABR ± diagnostic auditory brainstem response tests within one month of age. ResultsThe pass rate for AABR (67.9%) was higher than DPOAE (50.1%). Both DPOAE and AABR pass rates improved significantly with increasing age (p-value<0.001). The highest pass rate for both DPOAE and AABR were between the age of 36–48 h, 73.1% and 84.2% respectively. The mean testing time for AABR (13.54 min ± 7.47) was significantly longer than DPOAE (3.52 min ± 1.87), with a p-value of <0.001. ConclusionsOAE test is faster and easier than AABR, but with higher false positive rate. The most ideal hearing screening protocol should be tailored according to different centre.

Ambient noise levels and hearing screening outcomes: where technology meets clinical decision making

Purpose: The current study aimed to determine the mean ambient noise levels within a risk-based newborn hearing screening (NHS) programme. It further aimed to investigate the relationship between the ambient noise levels and the screening outcome. A descriptive, longitudinal, repeated measures, within-subjects design was employed. Three hundred and twenty-five neonates from two public sector hospitals were enrolled in an NHS programme.Methods: These neonates underwent an initial hearing screening in the wards, and were thereafter booked for a repeat hearing screening which was conducted in an outpatient clinic within the hospital setting. Screening included transient evoked otoacoustic emissions (TEOAEs), distortion product otoacoustic emissions (DPOAEs) and automated auditory brainstem response (AABR). The maximum ambient noise levels were measured and recorded for each screening session. Data related to mean ambient noise levels were analysed using descriptive statistics. The independent samples t-test and the Wilcoxon rank sum test were used to determine the association between the ambient noise levels and screening outcomes.Results: Results indicated that the ambient sound levels were significantly higher for ears which referred, compared to ears which passed.Conclusion: Findings from the current study highlight the need for monitoring of ambient noise levels across all screening contexts, and consideration of the inclusion of sound level measurements when planning for hearing screening programmes, particularly for contexts where environmental adaptations may not be possible.

Sensorineural Hearing Loss in Newborns Hospitalized in Neonatal Intensive Care Unit: An Observational Study.

Children hospitalized in Neonatal Intensive Care Units (NICU) present an increased risk for Sensorineural Hearing Loss (SNHL) due to prematurity, hypoxia-ischemia, hyperventilation, low birth weight and the use of ototoxic drugs. The aim of this study was to assess the prevalence of SNHL in newborns hospitalized in a NICU using Transient Evoked Otoacoustic Emissions (TEOAE) and Automated Auditory Brainstem Responses (A-ABR) and analyze the associated risk factors. A sample of 153 newborns hospitalized in NICU underwent TEOAE, A-ABR and clinical ABR to evaluate the presence of hearing deficits. Prevalence of SNHL was calculated and odds ratio for specific risk factors was measured. One-hundred fifteen babies (86.7%) presented normal hearing at TEOAE and A-ABR. Fifteen children had a REFER response at TEOAE and a PASS response at A-ABR. Twenty-five children (16.3%) had a REFER A-ABR and were addressed to clinical ABR. A diagnosis of SNHL was made in 12 (7.8%) newborns. An increased risk of SNHL was observed in preterm children <28 weeks (p=0.0135), in children with neurological disorders (p=0.02), that underwent surgery (p=0.0002), affected from premature retinopathy (p=0.0006), craniofacial malformation (p=0.007) and that had sepsis (p=0.04). Additional risk factors for SNHL in our sample were a maternal disease during pregnancy (p=0.0011), cesarean delivery (p<0.0001) and a twin pregnancy (p<0.0001). SNHL in newborns is correlated with hospitalization in NICU. An accurate hearing screening associated to a rigorous clinical medical collection of data is necessary to promptly identify cases of SNHL in children with a special attention to those hospitalized in NICU and plan proper intervention.

Evaluation of the Hearing in Children of Mild and Severe Pre-Eclamptic Mothers

Abstract Aim: This study is realized with the aim to investigate whether or not there is congenital and progressive hearing loss in the children aged between 1 and 4 whose mothers experienced mild or severe preeclampsia in their pregnancy. Material and Methods: Total 60 children participated in the study whose mothers had mild preeclampsia [20 children] and severe preeclampsia [20 children] and whose mothers were healthy [20 children] for the control group. After the Ear-Nose-Throat [ENT] examination, immitansmetric examination, otoacoustic emission test, Automatic Auditory Brainstem Response [A-ABR] measurement and Free Field [FF] audiometry were applied to the children. Result: As a result of audiological evaluation, Type C tympanogram was observed in the right ear of one child in the group with mild preeclampsia, and in the left ears of total four children in the group with severe preeclampsia [2 children] and in the healthy group [2 children]. No ipsilateral reflex was obtained in the right ears of total two children in the groups with mild [1 child] and severe [1 child] preeclampsia, and in the left ear of one child in the group with severe preeclampsia. One child in the group with mild preeclampsia did not pass from the OAE test. Normal immitansmetric findings and passed result from OAE test were obtained in the second audiological evaluation. All children passed the Automatic Auditory Brainstem Response [A-ABR] test. Hearing thresholds between 125-4000 Hz were obtained in the FF and at 30 dB. Conclusion: When comparison is made between the hearings of children whose mothers were healthy and have experienced preeclampsia; normal hearing findings were obtained for groups, and it is considered that preeclampsia did not cause any congenital and/or progressive hearing loss by it.

Hearing impairment and hypoxia ischaemic encephalopathy: Incidence and associated factors.

To establish the local incidence of hearing loss in newborns with Hypoxic Ischaemic Encephalopathy (HIE) and to identify associated risk factors. Retrospective Cohort Study. Neonatal Intensive Care Unit (NICU) dual stage hearing screening protocol, including automated otoacoustic emissions (AOAE) and automated auditory brainstem response (AABR) testing. 57 newborns received therapeutic hypothermia for HIE. Twelve babies (21%) died. Audiology data was incomplete in 3 babies. Complete data was available for 42 babies (male n=24), 4 (9.5%) of whom had hearing impairment. The development of hearing loss was associated with abnormal blood glucose levels (p=0.006), low Apgar score at 1min (p=0.0219) and evidence of multi organ dysfunction [high creatinine (p=0.0172 and 0.0198) and raised liver transaminases (aspartate aminotransferase (AST) p=0.0012, alanine aminotransferase (ALT) p=0.0037)]. An association with gentamicin was not found. This study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE. Blood glucose should be monitored carefully in these infants and developmental surveillance should include formal audiology. Further larger studies are needed to clarify the role, if any, of hypothermia per se in causation of hearing loss and to fully identify risk factors for hearing impairment in this population. The current study confirms that hearing impairment is common in term infants who have undergone therapeutic hypothermia for moderate/severe HIE. No association between gentamicin use and the development of hearing impairment was found however initial blood glucose outside the normal range was of significance. Other factors associated with hearing impairment were low Apgar scores, greater need for resuscitation and evidence of multi organ dysfunction (renal and liver failure).

Feasibility of infant hearing screening from a developing country context: the South African experience

Purpose: To explore the feasibility of infant hearing screening from a developing country context.Methods: A descriptive research design was employed, using a combination of surveys, questionnaires and face-to-face semi-structured interviews; as well as conduction of audiological measures such as otoacoustic emissions (OAEs) and automated auditory brainstem responses (AABR) during hearing screening. Participants comprised low–risk neonates, high-risk neonates and primary health care nursing managers.Results: Findings indicated that (1) screening at the Midwife Obstetric Unit 3-day assessment clinic may be more practical; (2) screening at primary health care clinics is not feasible until the identified barriers are addressed and; (3) factors such as ambient noise levels, availability of space for screening and time of discharge influence the practicability and efficiency of screening within a hospital context.Conclusion: There are a number of factors which influence the practicability and efficiency of newborn hearing screening. Each of these factors may vary depending on the level of healthcare setting and may either facilitate or act as barriers toward the implementation of newborn hearing screening in the South African context.

The Prevalence and Causes of Auditory Neuropathy/Dys-synchrony (AN/AD) in Children with Hearing Impairment.

There are a wide variety of hearing impairments that part of it is auditory neuropathy/dys-synchrony (AN/AD). So, the object of this study was determination the prevalence and causes of AN/AD in children with hearing impairment. This study was a descriptive cross-sectional survey. The sample size consisted of 105 hearing impairment children. All them were under hearing screening tests (tympanometry), distortion and transient evoked otoacoustic emissions (DPOAEs + TEOAE) and automated auditory brainstem response (AABR). If they were suspected to AN/AD, for complete diagnostic measurements were referred to our hospital. Four cases (8 ears) with AN/AD were diagnosed, which had an average age 37months (SD = 8.67). So, the prevalence of AN/AD was 3.8% among hearing impaired children. The findings of this study showed that there are the relationships between AN/AD and fluctuating hearing loss, acoustic reflex, high bilirubin, blood exchange after birth, neonatal intensive (NICU) care unit (P < 0.05). The simultaneous use of both ABR and OAE tests in the birth screening provide much more useful information than when each of these tests is used alone.

Prevalence of Hearing Impairment Among High-Risk Newborns in Ibadan, Nigeria.

The burden of severe hearing impairment is increasing with two-thirds of these hearing impaired people residing in developing countries. Newborn hearing screening helps to identify early, babies who need intervention in order to prevent future disability. Neither universal nor targeted hearing screening programme is available in Nigeria.Objectives: This study was carried out to assess the prevalence of hearing impairment among high-risk newborns in UCH and the associated risk factors.Materials and Methods: Two hundred one newborns in the neonatal unit of UCH with risk factors for hearing impairment had hearing screening done using automated auditory brainstem response (AABR) at 30, 45, and 70 dB at admission and discharge, and those that failed screening at discharge were rescreened at 6 weeks post-discharge.Results: Eighty-three (41.3%) and 32 (15.9%) high-risk newborns failed at admission and discharge screening respectively, and 19 (9.5%) still failed at follow up screening. The majority of hearing loss at follow up was bilateral (94.7%) and severe (52.6%). The risk factors associated with persistent hearing loss at follow up were acute bilirubin encephalopathy (RR = 11.2, CI: 1.4–90.6), IVH (RR = 8.8, CI: 1.1–71.8), meningitis (RR = 4.8, CI: 1.01–29), recurrent apnoea (RR = 2.7, CI: 1.01–7.3), severe perinatal asphyxia NNE III (RR = 7, CI: 2.4–20.2).Conclusion: Severe and bilateral hearing impairment is a common complication among high risk newborns in UCH persisting till 6 weeks post-neonatal care. Severe perinatal asphyxia with NNE III, ABE, IVH, meningitis and administration of amikacin for more than 5 days were significant risk factors. We recommend that SCBU graduates with these risk factors should have mandatory audiologic evaluation at discharge.