The Association between Prenatal Nicotine Exposure and Offspring's Hearing Impairment

OBJECTIVES

 The objective of this study is to evaluate whether there is an association between in-utero exposure to nicotine and subsequent hearing dysfunction.

MATERIALS AND METHODS

 Secondary analysis of a multicenter randomized trial to prevent congenital cytomegalovirus (CMV) infection among gravidas with primary CMV infection was conducted. Monthly intravenous immunoglobulin hyperimmune globulin therapy did not influence the rate of congenital CMV. Dyads with missing urine, fetal or neonatal demise, infants diagnosed with a major congenital anomaly, congenital CMV infection, or with evidence of middle ear dysfunction were excluded. The primary outcome was neonatal hearing impairment in one or more ears defined as abnormal distortion product otoacoustic emissions (DPOAEs; 1 to 8 kHz) that were measured within 42 days of birth. DPOAEs were interpreted using optimized frequency-specific level criteria. Cotinine was measured via enzyme-linked immunosorbent assay kits in maternal urine collected at enrollment and in the third trimester (mean gestational age 16.0 and 36.7 weeks, respectively). Blinded personnel ran samples in duplicates. Maternal urine cotinine >5 ng/mL at either time point was defined as in-utero exposure to nicotine. Multivariable logistic regression included variables associated with the primary outcome and with the exposure (p < 0.05) in univariate analysis.

RESULTS

 Of 399 enrolled patients in the original trial, 150 were included in this analysis, of whom 46 (31%) were exposed to nicotine. The primary outcome occurred in 18 (12%) newborns and was higher in nicotine-exposed infants compared with those nonexposed (15.2 vs. 10.6%, odds ratio [OR] 1.52, 95% confidence interval [CI] 0.55-4.20), but the difference was not significantly different (adjusted odds ratio [aOR] = 1.0, 95% CI 0.30-3.31). This association was similar when exposure was stratified as heavy (>100 ng/mL, aOR 0.72, 95% CI 0.15-3.51) or mild (5-100 ng/mL, aOR 1.28, 95% CI 0.33-4.95). There was no association between nicotine exposure and frequency-specific DPOAE amplitude.

CONCLUSION

 In a cohort of parturients with primary CMV infection, nicotine exposure was not associated with offspring hearing dysfunction assessed with DPOAEs.

KEY POINTS

· Nicotine exposure was quantified from maternal urine.. · Nicotine exposure was identified in 30% of the cohort.. · Exposure was not associated with offspring hearing dysfunction..

Covid-19 infection in pregnant women: Auditory evaluation in infants

 Recent studies showed that COVID-19 infection can affect cochleo-vestibular system. The possibility of a vertical transmission is controversial. Some studies suggested that it is possible but unlikely, others find no evidence of vertical transmission. The objective of this study was to investigate whether exposure to COVID-19 during pregnancy or at birth has an impact on the hearing of the offspring. As part of the national hearing screening program, we performed in all newborns between January 2022 and February 2023, TEOAEs (Transient Evoked Otoacoustic Emissions) at birth and at 3 months. For those "REFER" at the third month test, we performed aABR (Automatic Auditory Brainstem Response) at 6 months. We analysed separately result between infants born to COVID-positive mothers during pregnancy and those born to COVID-negative mothers. To statistical verify differences we performed "Chi-square test". We enrolled a total of 157 infants, of whom 16 were born to mothers who had a molecular PCR test positive for COVID-19. In the latter we tested a total of 32 ears and only 1 ear (3,1%) resulted "REFER". On the other hand, in the control group we tested a total of 282 ears and 22 (7,8%) were found to be "REFER". Our study showed no significant differences in audiological assessment between newborns exposed to COVID-19 infection during pregnancy or at birth compared to the unexposed group. However, further studies with a larger patient's sample will be necessary for a more comprehensive evaluation.

Neonatal Hearing Rescreening in a Second-Level Hospital: Problems and Solutions

Second-level hospitals face peculiarities that make it difficult to implement hearing rescreening protocols, which is also common in other settings. This study analyzes the hearing rescreening process in these kinds of hospitals. A total of 1130 individuals were included; in this cohort, 61.07% were hospital newborns who failed their first otoacoustic emission test after birth (n = 679) or were unable to perform the test (n = 11), and who were then referred to an outpatient clinic. The remaining 38.93% were individuals born in another hospital with their first test conducted in the outpatient clinic (n = 440). A high number of rescreenings were made outside of the recommended time frame, mainly in children referred from another hospital. There was a high lost-to-follow-up rate, especially regarding otolaryngologist referrals. Neonatal hearing screening at second-level hospitals is difficult because of staffing and time constraints. This results in turnaround times that are longer than recommended, interfering with the timely detection of hearing loss. This is particularly serious in outpatient children with impaired screening. Referral to out-of-town centers leads to unacceptable follow-up loss. Legislative support for all these rescreening issues is necessary. In this article, these findings are discussed and some solutions are proposed.

Analysis of congenital hearing loss after neonatal hearing screening

Introduction

Neonates undergo neonatal hearing screening to detect congenital hearing loss at an early stage. Once confirmed, it is necessary to perform an etiological workup to start appropriate treatment. The study objective was to assess the different etiologies, risk factors, and hearing results of infants with permanent hearing loss and to evaluate the efficacy and consequences of the different screening devices over the last 21 years.

Methods

We conducted a single-center retrospective cohort analysis for all neonatal hearing screening program referrals and performed an etiological workup in case of confirmed hearing loss. We analyzed the evolution of the etiological protocols based on these results.

Results

The governmental neonatal hearing screening program referred 545 infants to our center. Hearing loss was confirmed in 362 (66.4%) infants and an audiological workup was performed in 458 (84%) cases. 133 (24.4%) infants were diagnosed with permanent hearing loss. Ninety infants (56 bilateral and 34 unilateral) had sensorineural hearing loss, and the degree was predominantly moderate or profound. The most common etiology in bilateral sensorineural hearing loss was a genetic etiology (32.1%), and in unilateral sensorineural hearing loss, an anatomical abnormality (26.5%). Familial history of hearing loss was the most frequently encountered risk factor.

Conclusion

There is a significant number of false positives after the neonatal hearing screening. Permanent hearing loss is found only in a limited number of infants. During the 21 years of this study, we noticed an increase in etiological diagnoses, especially genetic causes, due to more advanced techniques. Genetic causes and anatomical abnormalities are the most common etiology of bilateral and unilateral sensorineural hearing loss, respectively, but a portion remains unknown after extensive examinations.

Expanded targeted screening for congenital cytomegalovirus infection

An early diagnosis and intervention for congenital cytomegalovirus infection can reduce long-term disability; however, the introduction of universal neonatal screening has been controversial worldwide. The present study clarified the outcome of a targeted screening protocol for detecting congenital cytomegalovirus infection based on suggestive perinatal conditions. In addition, the positive rate was compared to those from the reported studies and the validity of the targeted screening criteria was discussed. A total of 2121 newborn infants were admitted to our hospital between October 2018 and October 2021. Cytomegalovirus DNA was examined by the isothermal nucleic acid amplification method for urine samples from newborns with any of the following: microcephaly, abnormal ultrasound findings in the brain and visceral organs, repeated failure in neonatal hearing screening, suspicious maternal cytomegalovirus infection during pregnancy, and other abnormal findings suggestive of congenital cytomegalovirus infection. Among 2121 newborns, 102 (4.8%) were subject to the urine cytomegalovirus DNA test based on the abovementioned criteria. Of them, three were cytomegalovirus DNA-positive. According to the protocol, the cytomegalovirus DNA-positive rates were 0.14% among the total enrollment of 2121 newborns and 2.9% (3/102) among the targeted newborns. This protocol may overlook congenital cytomegalovirus infection that is asymptomatic or exhibits inapparent clinical manifestations only at birth; however, it is feasible and helps lead to the diagnosis of congenital cytomegalovirus infection that may otherwise be overlooked.

Early Hearing Detection and Intervention Results in Northeastern of Iran from 2005 to 2019: A Repeated Cross-Sectional Study

Background

Hearing loss is one of the most common congenital disorders. The Early Diagnosis and Intervention Process is designed for the early diagnosis and intervention of hearing loss in infants. The present study aimed to examine the results of Early Hearing Detection and Intervention (EHDI) in northeastern Iran from 2005 to 2019.

Setting

Northeastern Iran.

Methods

In most cases, the two-stage protocol (otoacoustic emissions [OAE] and automated auditory brainstem response [AABR]) has been used. Infant assessment methods included the use of OAE, ABR, auditory steady-state response, high-frequency tympanometry, and behavioral audiometry. Interventions included medical interventions, hearing rehabilitation, hearing aids, and cochlear implants.

Results

1,162,821 infants were screened. The screening coverage increased from less than 1% in 2005 to about 99% in 2018. The referral rate has been about 1%. 2.17 out of every 1000 infants are hearing impaired, and the most common cases are bilateral hearing loss and mild to moderate hearing loss.

Conclusions

During 2005 to 2019 the coverage rate reached to more than 95% of live births. To improve the EHDI process in this population, better follow-up of diagnosed neonates and expansion of diagnostic and intervention services are needed.

Keypoints to Successful Newborn Hearing Screening. Thirty Years of Experience and Innovations

Congenital deafness is a major pediatric problem, affecting about 1.5–3 per 1000 newborns. The early treatment through cochlear implantation and auditory rehabilitation has been a historic milestone. Early diagnosis of congenital deafness is an essential requirement to obtain the best results, which is achieved through neonatal screening, a diagnostic practice that we began systematically at the Hospital Clínico in Valencia (Spain) 30 years ago. Neonatal hearing screening is successful in most developed countries. Its implementation has been slow due to the multiple difficulties that its universal application entails since it involves several health professionals and must be carried out, in a short time interval after birth. In addition, it must have a good performance that prevents the overload of other services and that requires experience and continuous adjustments in search of proper protocols. The aim of this review is to shed some light on some key points of neonatal hearing screening, highlighting our experience in the solutions to common problems. We will discuss about techniques, protocols and neonatal or nutritional factors that can influence the screening results. To a summary of our work, an update on the subject is provided with the intention of sharing experiences and facilitating the start-up of the new units.

Our newborn hearing screening results

OBJECTIVE:

The aim of the study was to evaluate the results of neonatal hearing screening in our hospital with the help of literature and to question and reveal the risk factors to gain healthy individuals and to raise awareness for all health workers and the public who are interested in this subject.

METHODS:

A total of 16,388 newborn infants were evaluated between October 2009 and January 2018. All newborns were screened with transient evoked otoacoustic emissions (TEOAEs) test. Risk factors were investigated. The test repetition and auditory brainstem response (ABR) measurements were performed on newborns who could not pass the TEOAE test and the newborns in the risky group after 15 days.

RESULTS:

A total of 116 newborns (0.7%) were suspected to have hearing loss. Twenty-seven newborns (0.16%) were found to be in intensive care unit. Twelve newborns (0.07%) had permanent hearing loss. Then, in order: 9 newborns (0.05%) had received phototherapy and 7 newborns (0.04%) were born to consanguineous marriages. In addition, 3 newborns (0.02%) had a low birth weight and 1 newborn (0.006%) had a history of fever.

CONCLUSION:

Screening tests should be performed in all newborns for early detection of hearing loss. Even though frequency of hearing loss is higher in newborns with risk factors, the treatment should be started within 6 months, the latest, and newborns should be referred for rehabilitation and training.

Comparison of Two-Step Transient Evoked Otoacoustic Emissions and One-Step Automated Auditory Brainstem Response for Universal Newborn Hearing Screening Programs in Remote Areas of China

Objective: To compare the hearing screening results of two-step transient evoked otoacoustic emissions (TEOAE) and one-step automatic auditory brainstem response (AABR) in non-risk newborns, and to explore a more suitable hearing screening protocol for infants discharged within 48 h after birth in remote areas of China. Methods: To analyze the age effect on pass rate for hearing screening, 2005 newborns were divided into three groups according to screening time after birth: <24, 24-48, and 48-72 h. All subjects received TEOAE + AABR test as first hearing screen, and those who failed in any test were rescreened with TEOAE + AABR at 6 weeks after birth. The first screening results of AABR and TEOAE were compared among the three groups. The results of two-step TEOAE screening and one-step AABR screening were compared for newborns who were discharged within 48 h. The time spent on screening was recorded for TEOAE and AABR. Results: The pass rate of TEOAE and AABR increased significantly with the increase of first screening time (P < 0.05), and the false positive rate decreased significantly with the increase of first screening time (P < 0.05). The failure rate of first screening of AABR within 48 h was 7.31%, which was significantly lower than that of TEOAE (9.93%) (P < 0.05). The average time spent on AABR was 12.51 ± 6.36 min, which was significantly higher than that of TEOAE (4.05 ± 1.56 min, P < 0.05). The failure rate of TEOAE two-step screening was 1.59%, which was significantly lower than one-step AABR. Conclusions: Compared with TEOAE, AABR screening within 48 h after birth can reduce the failure rate and false positive rate of first screening. However, compared with TEOAE two-step screening, one-step AABR screening has higher referral rate for audiological diagnosis. In remote areas of China, especially in hospitals with high delivery rate, one-step AABR screening is not feasible, and two-step TEOAE screening protocol is still applicable to UNHS screening as more and more infants discharged within 48 h after birth.

Maturation of the auditory system in normal-hearing newborns with a very or extremely premature birth

BACKGROUND

Literature shows that lower gestational age leads to greater delays in the auditory conduction, which suggests atypical maturation of the brainstem in normal-hearing premature newborns. Our aim is to investigate if there is a difference between the extrauterine and intrauterine maturation of the auditory system in normal-hearing newborns with a very premature (28-31 weeks) or extremely premature (<28 weeks) birth.

METHODS

Results of the Automated Auditory Brainstem Response Newborn Hearing Screening Program in Dutch Neonatal Intensive Care Units and diagnostic examinations were centrally registered from 1998 to 2016. Normal-hearing newborns with a gestational age of 25-31 weeks were included. Screening results at 32-45 weeks of postmenstrual age were compared between newborns born with different gestational ages. Multiple imputation was used to predict missing screening results. Small for gestational age was defined as birth weight corrected for gestational age < -1.6 standard deviation. Descriptive and (pooled) logistic regression analyses were performed.

RESULTS

23,964 newborns with 28,754 screening results were eligible. At the same postmenstrual age, pass rates were lower when gestational age was lower in normal-hearing newborns with a very and extremely preterm birth. Pass rates of 80% could be obtained at 34-35, 32-33, and 30-32 weeks' postmenstrual age in newborns with 25, 26-27, 28-31 weeks gestational age, respectively. Small for gestational age had an additional negative effect on pass rates.

CONCLUSION

Analysis of hearing screening data suggests that extrauterine maturation of the auditory system is delayed in normal-hearing newborns with a very or extremely premature birth.

Prevalence of permanent neonatal hearing impairment: systematic review and Bayesian meta-analysis

Objective: To investigate the variance in reported prevalence rates of permanent neonatal hearing impairment (HI) worldwide.Design: A systematic review and meta-analysis was performed on reported prevalence rates of sensorineural and permanent conductive or mixed HI worse than 40 dB in neonates, detected as a result of a screening programme or audiometric study.Study sample: For meta-analysis, 35 articles were selected, 25 from high-income countries and 10 from middle-income countries according to the world bank classification system.Results: The prevalence rate of permanent uni- and bilateral HI worse than 40 dB in neonates varied from 1 to 6 per 1000, the overall prevalence was 2.21 per 1000 [1.71, 2.8]. In NICU populations the prevalence rate was higher with a larger fraction of bilateral cases. Although not significant, prevalence rates were slightly higher in Asia compared to Europe and the number of infants lost to follow-up appeared higher in countries with lower gross national income.Conclusion: Substantial variations exist in prevalence rates of neonatal permanent HI across countries and regions. There is a strong need for more data from low-income countries to identify demographic factors that account for this variability in reported prevalence rates. Reporting these data in a uniform way is advocated.

[Hearing assessment and follow-up study of aeonatal deafness gene screening homozygous mutation infants]

Objective:To analyze the hearing assessment characteristics and follow-up of some deafness gene screening homozygous infants in Zhuhai. Method:The clinical data of 28 newborns with homozygous mutations transferred to Zhuhai Maternal and Child Health Hospital from Feb. 1, 2015 to Oct. 25, 2018 in hospitals of Zhuhai City were retrospectively analyzed. All the children were screened for hearing. The hearing characteristics and long-term follow-up results of homozygous mutations at different gene sites were analyzed by auditory diagnosis and behavioral follow-up from 1 to 3 years. Result:Fourteen cases of GJB2 c.109G>A with a homozygous mutation, 11 cases passed the hearing screening, the audiological diagnosis was normal, and the behavior test and follow-up were normal from 1 to 3 years. Hearing screening was not passed in 3 newborns, mild to moderate abnormalities of single or bilateral ears were diagnosed by audiology, 1 000 Hz without positive, and middle ear lesions were diagnosed. Eight cases of GJB2 c.235del C homozygous mutation were followed up by behavioral audiometry and follow-up from 1 to 3 years after cure. Among them, 5 cases were diagnosed as severe hearing impairment of bilateral ears and 3 cases as mild and moderate hearing impairment. One case of GJB3 547G>A homozygous mutation was followed up for 1-3 years, and all of them failed to pass the follow-up of behavioral audiometry and follow-up. Four cases of SLC26A4 IVS7-2A>G, 1 case of SLC26A4 1229C>T homozygous mutation, all of them failed to pass the neonatal hearing screening. All the patients were diagnosed as severe hearing impairment of binaural hearing, and the follow-up of 1-3 years' follow-up did not pass the follow-up tests. Conclusion:GJB2 C.235del C, SLC26A4 IVS7-2A>G locus homozygous mutation infant hearing impairment was mainly severe hearing impairment in bilateral ears, and there was no change in 1-3 years follow-up. GJB2 C.109G A homozygous mutant infants had normal hearing, and it was suggested that they should be followed up closely. It is very important to give correct and reasonable genetic counseling to parents with GJB2 C.109G A homozygous mutation without unnecessary panic.

Newborn and Infant Hearing Screening Facing Globally Growing Numbers of People Suffering from Disabling Hearing Loss

Recent prevalence estimates indicate that in 2015 almost half a billion people-about 6.8% of the world's population-had disabling hearing loss and that prevalence numbers will further increase. The World Health Organization (WHO) currently estimates that at least 34 million children under the age of 15 have disabling hearing loss. Based on a 2012 WHO report, approximately 7.5 million of these children were under the age of 5 years. This review article focuses on the importance of high-quality newborn and infant hearing screening (NIHS) programs as one strategy to ameliorate disabling hearing loss as a global health problem. Two WHO resolutions regarding the prevention of deafness and hearing loss have been adopted urging member states to implement screening programs for early identification of ear diseases and hearing loss in babies and young children. The effectiveness of these programs depends on factors such as governmental mandates and guidance; presence of a national committee with involvement of professionals, industries, and stakeholders; central oversight of hearing screening; clear definition of target parameters; presence of tracking systems with bi-directional data transfer from screening devices to screening centers; accessibility of pediatric audiological services and rehabilitation programs; using telemedicine where connectivity is available; and the opportunity for case discussions in professional excellence circles with boards of experts. There is a lack of such programs in middle- and low-income countries, but even in high-income countries there is potential for improvement. Facing the still growing burden of disabling hearing loss around the world, there is a need to invest in national, high-quality NIHS programs.

Updating the nationwide methodology for hearing screening of newborns in the Czech Republic

Screening programs examining neonatal hearing serve to detect hearing defects, as a prerequisite for hearing rehabilitation, communication skills, and the enhancement of speech development. There are two methods through which neonatal hearing screening is carried out - the transiently evoked otoacoustic emissions (TEOAE) or the automatic BERA (AABR, automated auditory brainstem response). Positive screening means the discovery of a hearing defect (permanent hearing loss), and negative screening (normal TEOAE or the AABR results) means the absence of a hearing defect. The procedural aim is to update and adjust the neonatal hearing screening, which is determined by the Bulletin of the Ministry of Health of the Czech Republic No. 7/2012. Neonatal screening is performed at three levels: at neonatological site, at the ENT (phoniatric) rescreening site and at the ENT regional centre. The activities at each level are accurately and concretely identified including the issue of billing the performance to health insurance companies and informed consent to personal data protection (GDPR). The correct functioning of screening for hearing loss is based on the simple organization of the screening, patient examination comfort, medical recovery from it, and its economic viability. The schedule for neonatal hearing screening and rehabilitation recommends the following steps: 1. screening of a newborns hearing on the second or third day after delivery by a neonatological nurse using otoacoustic emissions, alternatively AABR for newborns at risk; 2. hearing rescreening in the third to sixth week of child`s age at the ENT rescreening site; 3. completion of hearing impairment diagnostics within three to sixth months of age at the ENT regional centre. The failure to follow the procedure above is a threat to the hearing and speech development of the child with severe permanent hearing impairment. The collaboration of ENT doctors with neonatologists and paediatricians allows for creating conditions under which the functional nationwide hearing screening of newborns can be established throughout the Czech Republic.

From Neonatal Hearing Screening to Intervention: Results of the Dutch Program for Neonatal Hearing Screening in Well Babies

In the Netherlands, Youth Health Care services (YHC) have been carrying out neonatal hearing screening (NHS) in newborns since 2006. The aim of the NHS is to identify children with permanent hearing loss, so that intervention can be started before the age of 4 months. Early detection of hearing loss is important, as children who start intervention early have been shown to develop better. This article describes the structure and performance of the NHS carried out by the YHC, the quality of the program, and the timeliness of the start of intervention. Since its implementation, the NHS has been audited annually in order to monitor the program's quality. Monitoring reports and data from the Dutch Foundation for the Deaf and Hard of Hearing Child were used in this study. For many years, results have shown the NHS to be a stable screening program of high quality. The participation rate is high, refer percentage low, and the timeliness of the program is continually improving. Although the timeliness of post screening diagnostics and intervention need most improvement as they do not always meet the target times, this has improved over recent years.

[International consensus (ICON) on audiological assessment of hearing loss in children]

Summary The prevalence of hearing loss in newborns and infants is estimated between 1 to 3.47 cases per 1000 live births. Neonatal screening for hearing loss and audiological evaluation are becoming more extensively carried out. However, there is no consensus regarding the use of audiometry and other electrophysiological tests in current practices. This article is intended to provide professionals with recommendations about the "best practice" based on consensus opinion of the session's speakers, and a review of the literature on the efficacy of various assessment options for children with hearing loss.

Two-Way Radio Modem Data Transfer for Newborn Hearing Screening Devices

INTRODUCTION

The success of a newborn hearing screening program depends on successful tracking and follow-up to ensure that children who have had positive screening results in the first few days of life receive appropriate and timely diagnostic and intervention services. The easy availability, through a suitable infrastructure, of the data necessary for the tracking, diagnosis, and care of children concerned is a major key to enhancing the quality and efficiency of newborn hearing screening programs.

MATERIALS AND METHODS

Two systems for the automated two-way transmission of newborn hearing screening and configuration data, based on mobile communication technology, for the screening devices MADSEN AccuScreen^® and Natus Echo-Screen^® were developed and tested in a field study. Radio modem connections were compared with conventional analogue modem transmissions from Natus Echo-Screen devices for duration, transmission rate, number of lost connections, and frequency of use.

RESULTS

The average session duration was significantly lower with the MADSEN AccuScreen (12 s) and Natus Echo-Screen both with radio modem (15 s) than the Natus Echo-Screen with analogue modem (108 s). The transmission rate was significantly higher (898 and 1,758 vs. 181 bytes/s) for the devices with radio modems. Both radio modem devices had significantly lower rates of broken connections after initial connection (2.1 and 0.9 vs. 5.5%). An increase in the frequency of data transmission from the clinics with mobile radio devices was found.

CONCLUSIONS

The use of mobile communication technology in newborn hearing screening devices offers improvements in the average session duration, transmission rate, and reliability of the connection over analogue solutions. We observed a behavioral change in clinical staff using the new technology: the data exchange with the tracking center is more often used. The requirements for on-site support were reduced. These savings outweigh the small increase in costs for the Internet service provider.

Newborn hearing screening: present scenario

In 2009 many countries of the world met to discuss newborn and infant hearing screening current issues and guiding principles for action under World Health Organization (WHO) banner, though most of the countries who had begun this work as universal program or high risk screen do not have exact data and protocol. The developing countries also decided to become part of it and common guideline was proposed. India being part of it included hearing screening as one of the 30 diseases to be screened under Rashtriya Bal Swasthya Karyakram (RBSK). This article discusses all these issues of newborn hearing screening in the world and India.

Low cost calibrated mechanical noisemaker for hearing screening of neonates in resource constrained settings

BACKGROUND & OBJECTIVES

There is a need to develop an affordable and reliable tool for hearing screening of neonates in resource constrained, medically underserved areas of developing nations. This study valuates a strategy of health worker based screening of neonates using a low cost mechanical calibrated noisemaker followed up with parental monitoring of age appropriate auditory milestones for detecting severe-profound hearing impairment in infants by 6 months of age.

METHODS

A trained health worker under the supervision of a qualified audiologist screened 425 neonates of whom 20 had confirmed severe-profound hearing impairment. Mechanical calibrated noisemakers of 50, 60, 70 and 80 dB (A) were used to elicit the behavioural responses. The parents of screened neonates were instructed to monitor the normal language and auditory milestones till 6 months of age. This strategy was validated against the reference standard consisting of a battery of tests - namely, auditory brain stem response (ABR), otoacoustic emissions (OAE) and behavioural assessment at 2 years of age. Bayesian prevalence weighted measures of screening were calculated.

RESULTS

The sensitivity and specificity was high with least false positive referrals for 70 and 80 dB (A) noisemakers. All the noisemakers had 100 per cent negative predictive value. 70 and 80 dB (A) noisemakers had high positive likelihood ratios of 19 and 34, respectively. The probability differences for pre- and post- test positive was 43 and 58 for 70 and 80 dB (A) noisemakers, respectively.

INTERPRETATION & CONCLUSIONS

In a controlled setting, health workers with primary education can be trained to use a mechanical calibrated noisemaker made of locally available material to reliably screen for severe-profound hearing loss in neonates. The monitoring of auditory responses could be done by informed parents. Multi-centre field trials of this strategy need to be carried out to examine the feasibility of community health care workers using it in resource constrained settings of developing nations to implement an effective national neonatal hearing screening programme.