ABR-based newborn hearing screening with MB11 BERAphone® using an optimized chirp for acoustical stimulation

Shortened neural conduction time in young adults with tinnitus as revealed by chirp-evoked auditory brainstem response

Tinnitus is generally considered to be caused by neuroplastic changes in the central nervous system, triggered by a loss of input from the damaged peripheral system; however, conflicting results on auditory brainstem responses (ABRs) to clicks have been reported previously in humans with tinnitus. This study aimed to compare the effect of tinnitus on ABRs to chirps with those to clicks in normal-hearing young adults with tinnitus. The results showed that the tinnitus group had no significantly poorer hearing thresholds (0.25-16 kHz), click-evoked otoacoustic emissions (1-16 kHz), and speech perception in noise (SPIN) than the control group. Although chirps evoked significantly larger wave I and V amplitudes than clicks, people with tinnitus had no significantly smaller wave I amplitudes for either stimulus. Nevertheless, adults with tinnitus exhibited significantly smaller interpeak interval (IPI) between waves I and V for chirps (IPI-chirp) but not for clicks. In addition, the IPI-chirp correlated significantly with the SPIN for individuals with tinnitus when the signal-to-noise ratio was low. The present results suggest that the chirp-evoked ABR may be a valuable clinical tool for objectively assessing the SPIN in individuals with tinnitus. Further studies should be conducted to investigate possible etiologies of tinnitus.

Analysis of barriers and facilitators to early hearing detection and intervention in KwaZulu-Natal, South Africa

Background

Objectives

Method

Results

Conclusion

Auditory Brainstem Response with chirp stimuli in newborns: an integrative review

ABSTRACT Purpose: to review the literature available on electrophysiological findings on ABR with chirp stimuli in newborns. Methods: articles were searched in PubMed, MEDLINE, Scopus, Web of Science, LILACS, and SciELO. Papers published in English and Portuguese between 2010 and 2020 were selected, including those that addressed ABR with air-conduction broadband chirp stimuli in newborns, that assessed ABR with a specific frequency, and that compared ABR results with chirp and click stimuli. Articles that assessed only bone-conduction results, duplicates, literature reviews, case reports, letters, and editorials were excluded. Literature review: the search strategy resulted in nine selected articles. Four studies (44.4%) analyzed ABR wave amplitude and latency with chirp stimuli, three studies (33.3%) compared the time of ABR procedures between chirp and click stimuli, two studies (22.2%) analyzed only amplitude, and two (22.2%), verified the specificity of ABR with chirp stimuli in neonatal hearing screening. Conclusion: chirp stimuli elicit responses with greater amplitudes, lower latencies, and shorter examination time than those with click stimuli in newborns.

PEATE por estímulo chirp em recém-nascidos: uma revisão integrativa

RESUMO Objetivo: revisar a literatura disponível sobre os achados eletrofisiológicos do PEATE por estímulo chirp em recém-nascidos. Métodos: a busca dos artigos foi realizada nas bases de dados PubMed, Medline, Scopus, Web of Science, LILACS e Scielo. Foram selecionados artigos publicados em Inglês e Português, entre 2010 e 2020. Foram incluídos artigos que contemplavam o uso do PEATE por estímulo chirp banda larga por via aérea em recém-nascidos; que avaliavam o PEATE por frequência específica e que comparavam os resultados do PEATE por estímulo chirp e clique. Aqueles que avaliavam somente resultados por via óssea, artigos repetidos nas bases de dados, artigos de revisão de literatura, relato de casos, cartas e editoriais foram excluídos. Revisão da Literatura: a estratégia de busca resultou na seleção de nove artigos. Quatro estudos (44,4%) analisaram amplitude e latência das ondas do PEATE por estímulo chirp, três (33,3%) compararam o tempo de realização do PEATE por clique e chirp, dois estudos (22,2%) analisaram somente o parâmetro amplitude e dois (22,2%) verificaram a especificidade do PEATE por chirp na triagem auditiva neonatal. Conclusão: o estímulo chirp possibilita respostas com maiores amplitudes, maiores latências e menor tempo de realização do exame quando comparado ao estímulo clique em recém-nascidos.

Twelve years of neonatal hearing screening: audiological and etiological results

PURPOSE

Most developed countries have implemented some form of universal newborn hearing screening program. Early identification and rehabilitation of congenital hearing loss is important in functional outcome, and the need to identify the cause of hearing impairment has become clear. We aimed to evaluate audiological and etiological outcomes in a large group of patients with failed neonatal hearing screening.

METHODS

We performed a retrospective chart analysis of patients who were referred to our tertiary referral center after failing neonatal hearing screening during a 12-year period (2007-2019). Screening was based on automated auditory brainstem response (AABR) or a combined approach of AABR and auditory steady-state response (ASSR) with chirp stimulus. Extensive audiometric testing was performed to confirm and determine the type and degree of hearing loss. In case of permanent hearing loss, a standardized etiological protocol was followed to determine the cause.

RESULTS

Of the 802 referred newborns, hearing loss was confirmed by diagnostic ABR in 78%. Main causes of hearing loss included otitis media with effusion (56%, higher in patients screened by AABR/ASSR compared to AABR), a genetic disorder (12%), congenital cytomegalovirus infection (cCMV, 5%) and atresia/stenosis of the external ear canal (5%). Of the patients with permanent hearing loss, 15% showed changes in hearing loss severity over time.

CONCLUSION

In the majority of newborns referred after failing universal neonatal hearing screening, hearing loss could be confirmed. The leading cause was reversible hearing loss due to otitis media with effusion, but hearing loss proved permanent in about 35% of referred newborns, with genetics as predominant cause. Follow-up of congenital hearing loss patients is important as deterioration as well as improvement was observed over time.

Comparison between MB11 BERAphone® and ALGO2e color for hearing screening in Japanese healthy newborns

BACKGROUND

Since 2001, newborn hearing screening has been performed in Japan.

OBJECTIVE

This study compared newborn hearing screening results between the MAICO MB11 BERAphone (MB11) and the Natus ALGO2e color (ALGO) Automated Auditory Brainstem Response (AABR) devices among healthy Japanese newborns.

MATERIALS AND METHODS

From December 2014 to April 2018, 1477 healthy newborns were screened by MB11 and 267 by ALGO. Data from at-risk newborns were not included. Outcomes were 'Pass' and 'Refer' rates, specificity, false-positive rates, and assessment duration. Infants with a Refer result were examined using Interacoustics Eclipse.

RESULTS

MB11 identified 1425 (96.5%) as Pass and 52 (3.5%) as Refer. ALGO identified 263 (98.5%) as Pass and four (1.5%) as Refer. Specificity and false-positive rates were 97.7% and 2.3% for MB11 and 98.5% and 1.5% for ALGO, respectively. Using MB11, the total mean assessment time was 320.2 ± 220.7 s, with 315.6 ± 214.2 s for Pass and 628.6 ± 288.8 s for Refer.

CONCLUSIONS

MB11 is useful for hearing screening in healthy Japanese newborns and is fast and easy to operate. MB11 showed high specificity equivalent to ALGO.

Effect of delivery mode on neonate auditory brainstem responses to air- and bone-conducted stimuli

OBJECTIVES

The object of this study was to examine if caesarean section delivered neonates have different middle ear function relative to neonates with vaginal delivery.

METHODS

Auditory brainstem responses (ABRs) were examined in caesarean section delivered (n = 23) and vaginally delivered (n = 29) neonates. ABRs were also evoked with air- and bone-conducted stimuli (i.e., clicks and CE-Chirps) and presented at a screening intensity level (i.e., 30 dB nHL). Wave V latencies and amplitudes were examined as a function of mode of delivery and stimuli.

RESULTS

Statistically significant longer wave V latencies evoked with air-conducted stimuli were seen in caesarean section delivered neonates (p = .042). There was no statistically significant difference in wave V latencies with bone-conducted stimuli among the two groups of neonates (p = .42). There were no significant differences in wave V amplitude between neonates with caesarean section and vaginal delivery for air-conducted (p = .42) stimuli. Wave V amplitudes were not significantly different as a function of mode of delivery with CE-Chirp stimulus (p = .41). Wave V amplitudes were significantly larger for the caesarean section delivered neonates with the bone-conducted click stimulus (p = .036).

CONCLUSIONS

The ABR wave V latency disparity with air- and bone-conducted stimuli support the notion that differences in middle ear function exist between the two groups of newborns. It was speculated that delayed fluid resorption in the middle ear exists in neonates with caesarean section delivery compared to those with vaginal delivery.

[Duration of automated auditory brainstem response test for the initial hearing screening and influencing factors for the duration in neonates]

OBJECTIVE

To study the duration of automated auditory brainstem response (AABR) test for initial hearing screening and the factors influencing the duration in neonates.

METHODS

A total of 472 neonates who were admitted to the neonatal intensive care unit (NICU) were enrolled as the study group and 182 healthy neonates were enrolled as the healthy control group. The influence of the duration of AABR test on the initial screening results was observed in the two groups. The influencing factors for the AABR test duration were analyzed.

RESULTS

In the AABR screening of 180, 360, and 540 seconds, the study group had a failure rate of 41.5%, 28.4%, and 24.4% respectively, while the healthy control group had a failure rate of 31.3%, 19.8%, and 15.4% respectively, showing a decreasing trend with the extension of test time in both groups (P<0.05). In the two groups, the screening results of 180-second testing were moderately consistent with those of 360- or 540-second testing (Kappa<0.75, P<0.05), and the screening results of 360-second testing were highly consistent with those of 540-second testing (Kappa>0.75, P<0.05). In the study group, the median duration of AABR test was 108 seconds (95%CI: 97-120 seconds), which was significantly longer than the duration of 75 seconds (95%CI: 65-85 seconds) in the healthy control group (P<0.05). The Cox regression analysis showed that maternal age ≥35 years, anemia, and electrolyte disturbance (RR<1, P<0.05) were independent risk factors for prolonged AABR test duration, while the prolonged continuous positive airway pressure-assisted ventilation was a protective factor (RR>1, P<0.05).

CONCLUSIONS

The AABR test time of 360-540 seconds for initial hearing screening helps to reduce false positive results due to environmental and risk factors in neonates. It may be useful to reduce the false positive results of AABR screening before discharge by taking corresponding intervention measures for NICU neonates with high risk factors.

Device optimised chirp stimulus for ABR measurements with an active middle ear implant

OBJECTIVE

Active middle ear implants are widely used to treat adults and children with sensorineural, conductive, or mixed hearing loss. Currently, there is no adequate method to determine the performance of active middle ear implant systems.

DESIGN

The proposed method is based on measuring the auditory brainstem response while stimulating the hearing system via the active middle ear implant (Vibrant Soundbridge^TM, VSB; MEDEL, Austria). The acoustic stimulation was achieved via an optimised chirp stimulus (CE-Chirp), implemented in the Eclipse system (Interacoustics, Denmark). To compensate for the frequency-specific delays in the VSB system, the underlying model function of the CE-Chirp was adjusted accordingly (VSB-CE-Chirp). Study samples: The study includes 12 subjects having mild to profound sensorineural, conductive or mixed hearing loss.

RESULTS

The use of an optimised VSB-CE-Chirp instead of the CE-Chirp increases significantly the ABR wave V amplitudes (1.63 times) and so also increases their identifiability (by 15.2%). On average, wave V could be identified at a 7.5 dB lower stimulation level.

CONCLUSION

The constructed VSB-CE-Chirp stimulus, after it had been transmitted through the VSB system, follows well the shape of the original CE-Chirp. Preliminary measurements in VSB patients demonstrated a significantly improved ABR amplitude with the VSB-CE-Chirp.

[Preoperative auditory evaluation and postoperative follow-up in cochlear implantees : The role of objective measures]

The primary diagnostic aim prior to cochlear implantation is establishment of a comprehensive and multidisciplinary diagnosis, in order to subsequently begin therapy as early as possible. Audiological evaluation prior to implantation employs a test battery-approach, including subjective and objective procedures. Objective measures show high reliability and therefore play a major role in the diagnosis of difficult-to-test subjects such as infants and young children. During postoperative follow-up, objective measures offer a valid method for analyzing the effects of different stimuli on the auditory system. Particularly in infants, children, and uncooperative patients, the results of these tests enable the speech processor settings to be optimized, the hearing benefit to be assessed, and treatment to be adapted accordingly. Auditory brainstem responses (ABR) offer an excellent test/retest and inter-/intrarater reliability and validity, and are the most commonly used method for objective hearing threshold estimation and evaluation of the functional integrity of the lower auditory pathway. The use of narrow-band stimuli allows frequency-specific threshold estimation; analysis of stationary auditory steady state potentials (ASSR) adds the advantages of automated objective detection. Electrocochleography and electrically evoked ABR give valuable information in special cases. The use of cortical potentials (CAEP) in response to speech stimuli is quite promising, although the high response variability currently limits this method's clinical application. An audiological test-battery approach combining the results of subjective and objective measures leads to significantly increased reliability of preoperative diagnosis and postoperative follow-up in cochlear implantees.

Auditory Brainstem Response Thresholds to Air- and Bone-Conducted CE-Chirps in Neonates and Adults

PURPOSE

The purpose of this study was to compare auditory brainstem response (ABR) thresholds to air- and bone-conducted CE-Chirps in neonates and adults.

METHOD

Thirty-two neonates with no physical or neurologic challenges and 20 adults with normal hearing participated. ABRs were acquired with a starting intensity of 30 dB normal hearing level (nHL). The lowest stimulus intensity level at which a wave V was identifiable and replicable was considered the ABR threshold.

RESULTS

ABR thresholds to air-conducted CE-Chirps were 9.8 dB nHL for neonates and adults. ABR thresholds to bone-conducted CE-Chirps were 3.8 and 13.8 dB nHL for neonates and adults, respectively. The difference in ABR thresholds to bone-conducted CE-Chirps was significantly different (p < .0001, ηp2 = .45). Adults had significantly larger wave V amplitudes to air- (p < .0001, ηp2 = .50) and bone-conducted (p = .013, ηp2 = .15) CE-Chirps at a stimulus intensity of 30 dB nHL. At the same intensity, adults evidenced significantly shorter wave V latencies (p < .0001, ηp2 = .49) only with air-conducted CE-chirps.

CONCLUSION

The difference in ABR thresholds and wave V latencies to air- and bone-conducted CE-Chirps between neonates and adults may be attributed to a disparity in effective signal delivery to the cochlea.

Feasibility of newborn hearing screening in a public hospital setting in South Africa: A pilot study

Objectives

The current pilot study aimed to explore the feasibility of newborn hearing screening (NHS) in a hospital setting with clinical significance for the implementation of NHS. Context-specific objectives included determining the average time required to screen each neonate or infant; the most suitable time for initial hearing screening in the wards; as well as the ambient noise levels in the wards and at the neonatal follow-up clinic where screening would be conducted.

Method

A descriptive, longitudinal, repeated measures, within-subjects design was employed. The pilot study comprised 11 participants who underwent hearing screening. Data were analysed using descriptive statistics.

Results

The average time taken to conduct hearing screening using otoacoustic emissions and automated auditory brainstem response was 18.4 minutes, with transient evoked otoacoustic emissions taking the least time. Ambient noise levels differed between wards and clinics with the sound level readings ranging between 50 dBA and 70 dBA. The most suitable screening time was found to be the afternoons, after feeding times.

Conclusion

Findings highlight important considerations when embarking on larger scale NHS studies or when planning a hospital NHS programme. Current findings suggest that NHS can be efficiently and effectively conducted in public sector hospitals in South Africa, provided that test time is considered in addition to sensitivity and specificity when deciding on a screening protocol; bar recognised personnel challenges.

Newborn hearing screening at a community-based obstetric unit: Screening and diagnostic outcomes

OBJECTIVE

Postnatal visits at community-based midwife obstetric units (MOUs) have been proposed as an alternative primary healthcare screening platform in South Africa. This study evaluated the outcomes of distortion product otoacoustic emissions (DPOAEs) and automated auditory brainstem response (AABR) screening conducted by a dedicated non-professional screener at a community-based MOU in the Western Cape, South Africa.

METHODS

Universal newborn hearing screening (UNHS) at a community-based MOU was evaluated over a 16-month period. A dedicated non-professional screener was trained to follow a two-stage screening protocol targeting bilateral hearing loss. A two group comparative design was used alternating AABR (Maico MB11 BERAphone™()) and DPOAE (Bio-logic AuDX I) technology on a daily basis. Infants referring the initial screen received a follow-up appointment in two days' time and were rescreened with the same technology used at their first screen. Those referring the second stage were booked for diagnostic assessments.

RESULTS

7452 infants were screened including 47.9% (n=3573) with DPOAE and 52.1% (n=3879) with AABR technology. Mean age at first stage screen was 6.1 days. The initial bilateral referral rate was significantly lower for AABR (4.6%) compared to DPOAE (7.0%) and dropped to 0.3% and 0.7% respectively following the second stage screenings. First rescreen and initial diagnostic follow-up rates of 90% and 92.3% were obtained for the DPOAE group and 86.6% and 90% for the AABR group. Follow-up rates showed no significant difference between technology groups. Diagnostic assessment revealed a higher prevalence rate for bilateral SNHL among the AABR group (1/1000) compared to the DPOAE group (0.3/1000). Screening technology had no significant influence on daily screening capacity (23 AABR/day; 24 DPOAE/day).

CONCLUSIONS

Postnatal visits at community-based MOUs create a useful platform for hearing screening and follow-up. AABR technology with negligible disposable costs provides opportunity for AABR screening to be utilised in community-based programmes. AABR screening offers lower initial referral rates and a higher true positive rate compared to DPOAE.

Chirp-Evoked Auditory Brainstem Response in Children: A Review

PURPOSE

The aim of this study was to assess the use of the chirp stimulus to record auditory brainstem responses in the pediatric population via a traditional review.

METHOD

An electronic search of the literature and a hand search of the literature were conducted. Studies that utilized chirp stimuli within the pediatric population that met all of the inclusion criteria were included in this review. Qualitative synthesis and interpretation of the data were completed.

RESULTS

Seven studies that met the inclusion criteria were included in the review. Chirp stimuli produce auditory brainstem response (ABR) waveform amplitudes in children similar to those in adults when presented at moderate to low frequency levels. Latency data from chirp stimuli are not consistent when stimulus presentation rates are altered. Test-retest reliability when using the chirp stimulus was found to be good, as were sensitivity and specificity of chirp-evoked ABRs utilized in a newborn hearing screening protocol.

CONCLUSION

Reviewed studies indicated that when presented at 60 dB nHL or lower, broadband chirp-generated ABRs have larger amplitudes than click-generated ABRs in children with normal hearing. Utilization of chirp stimuli decreases test time because waveforms are easier to detect with increased synchronization. Further research should focus on correlating chirp thresholds with behavioral hearing thresholds. Given the variance of results in these select studies, future research should also evaluate latency findings and focus on developing normative data for infants with hearing impairment and normal hearing.

Challenges of Implementing Universal Newborn Hearing Screening at a Tertiary Care Centre from India

OBJECTIVES

To report experience of implementing universal newborn hearing screening (UNHS) in a tertiary care neonatal unit, identify risk factors associated with failed two-step automated acoustic brainstem response (AABR) screen and evaluate cost of AABR.

METHODS

This was a prospective study of UNHS outcomes of all live births with two step AABR using BERAphone MB11®. Outcome measures were screening coverage, refer, pass and lost to follow up rates and cost of AABR using micro-costing method. To identify risk factors for failed screening, authors performed multivariate logistic regression with failed two-step AABR screen as dependent variable and baseline risk factors significant on univariate analysis as predictors.

RESULTS

Screening coverage was moderate (84 %), with 2265 of total 2700 eligible infants screened with initial AABR (mean gestation 37.2 ± 2.3 wk; birth weight 2694 ± 588 g; 305 received nursery care). A total of 273 of 2265 infants were "refer" on first screen. Second screen was done on 233, of which 58 were "refer". Of these, 35 underwent conventional ABR, of which 5 were diagnosed to have hearing impairment. Only 2 could get hearing aid. Overall, a total of 2197 (81.4 %) infants passed, 496 (18.4 %; excluding 2 deaths) were lost to follow up at various stages, and 5 (0.2 %) were diagnosed with hearing impairment, all of whom were high risk. Average cost of AABR was INR 276 per test. No factor emerged as significant on multivariate analysis.

CONCLUSIONS

UNHS is feasible to implement, but significant lost to follow up and non-linkage with appropriate rehabilitation services limit its utility. Cost effectiveness of UNHS compared to high risk based screening needs to be determined.

Evaluating reporting and process quality of publications on UNHS: a systematic review of programmes

Background

Congenital hearing loss is one of the most frequent birth defects, and Early Detection and Intervention has been found to improve language outcomes. The American Academy of Pediatrics (AAP) and the Joint Committee on Infant Hearing (JCIH) established quality of care process indicators and benchmarks for Universal Newborn Hearing Screening (UNHS). We have aggregated some of these indicators/benchmarks according to the three pillars of universality, timely detection and overreferral. When dealing with inter-comparison, relying on complete and standardised literature data becomes crucial.

The purpose of this paper is to verify whether literature data on UNHS programmes have included sufficient information to allow inter-programme comparisons according to the indicators considered.

Methods

We performed a systematic search identifying UNHS studies and assessing the quality of programmes.

Results

The identified 12 studies demonstrated heterogeneity in criteria for referring to further examinations during the screening phase and in identifying high-risk neonates, protocols, tests, staff, and testing environments. Our systematic review also highlighted substantial variability in reported performance data. In order to optimise the reporting of screening protocols and process performance, we propose a checklist. Another result is the difficulty in guaranteeing full respect for the criteria of universality, timely detection and overreferral.

Conclusions

Standardisation in reporting UNHS experiences may also have a positive impact on inter-program comparisons, hence favouring the emergence of recognised best practices.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0404-x) contains supplementary material, which is available to authorized users.

Neonatal hearing screening: what we have achieved and what needs to be improved

OBJECTIVE

To review the literature on neonatal hearing screening and its weaknesses with regard to missed follow-ups and delayed diagnosis and management.

RESULTS

The implementation of newborn hearing screening programs has indeed lowered the mean age of hearing loss identification and many deaf children are now diagnosed at an early age of some months. However, the present collection of 32 studies published in the International Journal of Pediatric Otorhinolaryngology revealed that late-onset deafness, auditory neuropathy, and the alarming percentage of newborns who fail the initial testing and then are lost to follow-up are major weaknesses of neonatal hearing screening programs. It seems that parents may be satisfied of hearing screening but in a significant percentage of them do not bring their children for follow-up or further testing due to phycho-social or other reasons. In addition, the same collection revealed that socioeconomic factors may have a significant influence on the effectiveness of hearing screening programs in the developed and developing countries, where improvements in health care politics, tracking system and public awareness is crucial for successful program implementation.

CONCLUSIONS

Neonatal hearing screening programs have changed the whole picture of congenital deafness as age identification has significantly fallen with a very positive effect on timely management. However, the selected and proposed 32 related articles published in the International Journal of Pediatric Otorhinolaryngology show that there are still serious weakness in the neonatal hearing screening that need improvements in order to achieve an efficient and cost-effective system of deafness identification.

Government-funded universal newborn hearing screening and genetic analyses of deafness predisposing genes in Taiwan

OBJECTIVE

To investigate the association of eight connexin genes (GJB2, GJB4, GJA1P1, GJB6, GJB3, GJA1, GJB1, and GJC3) and the SLC26A4 gene with congenital hearing impairment among infants in a universal newborn hearing screening program.

METHOD

From September 2009 to October 2013, the consecutive neonates born in all six branches of Taipei City Hospital were enrolled. Infants who failed the newborn hearing screening and were diagnosed with hearing impairment underwent the genetic analyses.

RESULT

15,404 neonates were born at Taipei City Hospital, and 15,345 neonates underwent newborn hearing screening. Among them, 32 infants were diagnosed with unilateral or bilateral hearing impairment. 26 of them underwent analyses of the connexin genes and the SLC26A4 gene. Of the connexin genes, two infants carried a GJB3 mutation (heterozygous c.580G>A and heterozygous c.520G>A, respectively). Only one infant carried a GJB2 mutation (homozygous c.235delC). One infant carried a GJA1P1 mutation (heterozygous c.929delC) and another carried a GJB4 mutation (heterozygous c.302G>A). Additionally, one infant carried a GJA1P1 novel variant (heterozygous c.1081C>T). Another infant carried a GJA1 novel variant (heterozygous c.1-33C>G). Of the SLC26A4 gene, one infant carried heterozygous c.919-2A>G mutation and a novel variant (heterozygous c.164+1G>C), and high-resolution computed tomography (HRCT) of the temporal bone revealed bilateral enlarged vestibular aqueducts. One infant carried heterozygous c.919-2A>G mutation and no inner ear anomalies were demonstrated by HRCT of the temporal bone. Another infant carried a novel variant (heterozygous c.818C>T).

CONCLUSION

These results provide a genetic profile of the connexin genes and SLC26A4 gene among infants with hearing impairment detected by a universal newborn hearing screening program in Taiwan. Further studies and long-term follow up of this cohort are warranted to determine the pathogenicity of each variants and the long-term hearing consequence.

Test-retest reliability of auditory brainstem responses to chirp stimuli in newborns

OBJECTIVE

The purpose of this study was to examine the test-retest reliability of auditory brainstem responses (ABRs) to air- and bone-conducted chirp stimuli in newborns as a function of intensity.

DESIGN

A repeated measures quasi-experimental design was employed.

STUDY SAMPLE

Thirty healthy newborns participated. ABRs were evoked using 60, 45, and 30 dB nHL air-conducted CE-Chirps and 45, 30, and 15 dB nHL bone-conducted CE-Chirps at a rate of 57.7/s. Measures were repeated by a second tester.

RESULTS

Statistically significant correlations (p <.0001) and predictive linear relations (p <.0001) were found between testers for wave V latencies and amplitudes to air- and bone-conducted CE-Chirps. There were also no statistically significant differences between testers with wave V latencies and amplitudes to air- and bone-conducted CE-Chirps (p >.05). As expected, significant differences in wave V latencies and amplitudes were seen as a function of stimulus intensity for air- and bone-conducted CE-Chirps (p <.0001).

CONCLUSIONS

These results suggest that ABRs to air- and bone-conducted CE-Chirps can be reliably repeated in newborns with different testers. The CE-Chirp may be valuable for both screening and diagnostic audiologic assessments of newborns.

Sensitivity of ABR based newborn screening with the MB11 BERAphone(®)

OBJECTIVES

The aim of this study is to evaluate the sensitivity of our hearing screening program. The evaluation was done using a questionnaire for parents of children who participated in the NHS for a targeted time frame of two years. A survey was accomplished to identify children who passed our screening protocol in the newborn period, but who were later identified to have hearing loss.

METHODS

For the survey a one-year cohort was established in 2008 which included 500 children who received a hearing screening at our Center with the ABR newborn screener, MB11 BERAphone(®), two years before. Two hearing questionnaires were chosen for the survey. The LittlEARS questionnaire (MED-EL Medical Electronics GmbH) for investigating the hearing behavior of the children during the first two years of life and a second, custom-developed questionnaire (Würzburger questionnaire) investigating some aspects which are not included in the LittlEARS tool, such as speech/language development, general development as well as pathological factors that might eventually lead to a temporary hearing loss.

RESULTS

Analysis of the Würzburger questionnaires revealed normal speech development for 92.9% of the children. For 4.7% male and 2.4% female children delayed speech development was reported. Although twice as many males were found, the statistical comparison showed no significant difference according to gender. The results of the LittlEARS questionnaire are identical to those of the Würzburger questionnaire in 98.3% of the investigated cases and in 1.7% of the cases slightly different results but on borderline: The LittlEAR scores showed normal auditory development for the childrens' age but the Würzburger questionnaire results showed delayed speech development.

CONCLUSIONS

Based on the follow-up analysis and the results from the two questionnaires, no permanent hearing loss was found in any child two years after they passed the newborn hearing screening. Thus, we conclude that the sensitivity of the screening test was 100%, based on survey results 2 years post screening.

Evaluation of waveform, latency and amplitude values of chirp ABR in newborns

OBJECTIVES

There has been a rapid growth in using chirp stimuli for evoking auditory brainstem response (ABR). This study aims to investigate the waveform morphology, latency, and amplitude values in newborns and compare them with those evoked by the click in order to determine whether chirp-evoked responses are easier to detect at near-threshold values, as has been proposed, and to assess the usefulness of the chirp stimulus in improving ABR detection thresholds in this population.

METHODS

Chirp- and click-evoked ABR were measured in 96 normal-hearing newborns (52 males and 44 females) using the MB11 BERAphone(®). Only children who passed the hearing screening and were not older than 5 days were included in this study. Two stimulation levels were used: 40 dB nHL and 60 dB nHL. The stimulation rate was 20.3s(-1). The recorded ABR were analyzed based on visual identification of waves I, III, and V, and their amplitude and latency values.

RESULTS

Chirp-evoked responses showed clearly larger wave amplitudes compared to those evoked by click stimulus. The gain in amplitude for wave V was 77% for 60 dB nHL and 100% for 40 dB nHL, for wave III the gain was 22% at 60 dB nHL and 46% at 40 dB nHL and for wave I the gain was 64% and 100%, respectively. Generally, the gain in amplitude associated with the chirp was greater at the lower stimulus level of 40 dB nHL. The wave's latencies were shorter in response to the chirp stimulus. Interpeak intervals differed between click-evoked and chirp-evoked ABR, slightly in the I-III interval and significantly in the I-V interval.

CONCLUSIONS

Chirp-evoked potentials are distinguished from click-evoked potentials by their significantly larger ABR amplitudes. Therefore they are expected to yield more reliable results and shorter measurement times. It should be noted that, for diagnostic purposes, the typical peak latencies of chirp-evoked ABR are clearly different to those of clicks.

Neonatal hearing screening--experience from a tertiary care hospital in southern India

OBJECTIVE

To implement a neonatal hearing screening program using automated auditory brainstem response audiometry in a tertiary care set-up and assess the prevalence of neonatal hearing loss.

DESIGN

Descriptive study.

SETTING

Tertiary care hospital in Southern India.

PARTICIPANTS

9448 babies born in the hospital over a period of 11 months.

INTERVENTION

The neonates were subjected to a two stage sequential screening using the BERAphone. Neonates suspected of hearing loss underwent confirmatory testing using auditory steady state response audiometry. In addition, serological testing for TORCH infections, and connexin 26 gene was done.

MAIN OUTCOME MEASURES

Feasibility of the screening program, prevalence of neonatal hearing loss and risk factors found in association with neonatal hearing loss.

RESULTS

164 babies were identified as suspected for hearing loss, but of which, only 58 visited the audiovestibular clinic. Among 45 babies who had confirmatory testing, 39 were confirmed to have hearing loss and were rehabilitated appropriately. 30 babies had one or more risk factors; 6 had evidence of TORCH infection and 1 had connexin 26 gene mutation.

CONCLUSION

Neonatal hearing screening using BERAphone is a feasible service. The estimated prevalence of confirmed hearing loss was comparable to that in literature. Overcoming the large numbers of loss to follow-up proves to be a challenge in the implementation of such a program.

Chirp-evoked otoacoustic emissions in children

OBJECTIVE

The purpose of the study was to investigate the properties of otoacoustic emissions (OAEs) evoked by chirp stimuli and compare them with standard click-evoked OAEs. Differences between evoked OAEs in children with and without spontaneous otoacoustic emissions (SOAEs) were also assessed.

METHODS

OAEs were first recorded from 54 children (age 4-10 years) in a screening setup. In each ear five OAE measurements were made using two types of chirps (7.5 ms and 10.5 ms) at around 70 dB pSPL; clicks at 70 and 80 dB pSPL; and a standard synchronized SOAE stimulation protocol. Tympanometry was also conducted. Pass/refer criteria based on signal to noise ratios (SNRs) were applied to all OAEs. Pass/refer rates from all methods (OAEs evoked by chirps and clicks, and tympanometry) were compared. Additionally, half-octave-band values of OAE SNRs and response levels were used to assess statistical differences.

RESULTS

Chirp-evoked OAEs generated a similar number of passes to click-evoked OAEs when the same level of stimulus was used. When using lower stimulus levels, both chirp- and click-evoked OAEs diagnosed nearly all ears that failed tympanometry. The response levels and SNRs of OAEs evoked by clicks and chirps were very similar. The highest response levels were in the 1.4 kHz half-octave band. The SNRs for ears with SOAEs were highest at 1.4 kHz, whereas they were at 4 kHz for ears without SOAEs. Both response levels and SNRs were higher by about 5 dB for ears with SOAEs than ears without SOAEs. Also all ears with SOAEs generated a pass result in screening, while ears without SOAEs gave a pass less frequently (at least 30% fewer cases).

CONCLUSIONS

The results suggest that performance of chirp-evoked OAEs for screening purposes is similar to click-evoked OAEs when the same stimulus level is applied. OAEs evoked with lower stimulus levels (70 vs. 80 dB pSPL) are more sensitive to middle ear pathology. The presence of SOAEs significantly influences the pass rates of OAEs evoked by chirps and clicks.

Features of unilateral hearing loss detected by newborn hearing screening programme in different regions of Turkey

OBJECTIVE

Newborn hearing screening (NHS) works well for babies with bilateral hearing loss. However, for those with unilateral loss, it has yet to be established some standard rules like age of diagnose, risk factors, hearing loss degree. The aim of this study is to identify the demographic characteristics of newborns with unilateral hearing loss to obtain evidence based data in order to see what to be done for children with unilateral hearing loss (UHL).

METHOD

Newborn hearing screening data of 123 babies with unilateral hearing loss, 71 (57.7%) male and 52 (42.3%) female, were investigated retrospectively. Data provided from the archives of six referral tertiary audiology centers from four regions in Turkey. Data, including type of hearing loss; age of diagnosis; prenatal, natal and postnatal risk factors; familial HL and parental consanguinity was analyzed in all regions and each of the Regions 1-4 separately.

RESULT

The difference between data obtained in terms of gender and type of hearing loss was detected as statistically significant (p<0.05). While UHL was significantly higher in females at Region 1, and in males at other Regions of 2-4; SNHL was the most detected type of UHL in all regions with the rate of 82.9-100.0%. There were not significant differences between regions in terms of the degree of hearing loss, presence of risk factors, family history of hearing loss, age at diagnosis and parental consanguinity (p>0.05). Diagnosis procedure was completed mostly at 3-6 months in Region 4; whereas, in other regions (Regions 1-3), completion of procedure was delayed until 6 months-1 year.

CONCLUSION

This study indicates that the effect of postnatal risk factors, i.e. curable hyperbilirubinemia, congenital infection and intensive care is relatively high on unilateral hearing loss, precautions should be taken regarding their prevention, as well as physicians and other health personnel should be trained in terms of these risks. For early and timely diagnosis, families will be informed about hearing loss and NHS programme; will be supported, including financial support of diagnosis process. By dissemination of the NHS programme to the total of country by high participation rate, risk factors can be determined better and measures can be increased. Additionally, further studies are needed with more comprehensive standard broad data for more evidence based consensus.

Implementation and results of bedside hearing screening with automated auditory brainstem response in the neonatal intensive care unit

AIM

To evaluate implementation and results of neonatal hearing screening with automated auditory brainstem response (AABR) by bedside nurses in a single-centre neonatal intensive care unit (NICU).

METHODS

Retrospective review of charts of 2074 newborns admitted over a 4-year period.

RESULTS

One thousand eight hundred and 24 newborns (88%) were screened. A 'pass' result was obtained in 1761 patients (96.5%). From 63 infants with 'refer', 40 were tested with auditory brainstem response: in 28 hearing loss was confirmed. Three hundred and nine neonates were screened before postmenstrual age (PMA) of 34 weeks: 78% successfully passed the first test. Sixty-seven infants with 'refer' at the first test before PMA of 34 weeks were re-evaluated: 48 had normal hearing tests, 24 of whom still younger than 34 weeks. For 12 of 19 infants with 'refer' before 34 weeks, follow-up was available: in 7 hearing loss was confirmed.

CONCLUSION

Neonatal hearing screening with AABR can be easily performed by the bedside nurse in the NICU even in premature babies before 34 weeks PMA. A 'pass' result can be obtained in almost 80% of them; a 'refer' result at that age, however, must be interpreted cautiously, as false 'refer' occurred in 5/12 of these infants.