Brainstem Response Audiometry Research Articles

Long-Term Follow-Up After Translabyrinthine IAC Tumor Removal With Simultaneous Cochlear Implantation.

To evaluate the long-term hearing outcome after translabyrinthine resection of tumors within the internal auditory canal (IAC) with simultaneous cochlear implantation (CI). Prospective study. Tertiary referral center. Thirty-seven patients with tumors of the IAC undergoing translabyrinthine tumor surgery as a first-line therapy. Intraoperatively, electrically evoked auditory brainstem response audiometry (eABR) was performed in all patients to assess cochlear nerve (CN) integrity. In case of preserved CN function after tumor removal, CI was subsequently performed. Postoperatively, patients were regularly followed up to evaluate pure-tone hearing as well as speech recognition with a monosyllabic word comprehension test. Postoperative hearing thresholds and word recognition scores. Of 37 included patients, 22 (59.46%) had positive eABR responses after tumor removal. Twenty-one of these underwent simultaneous CI directly after tumor surgery and were followed-up for 24.24 ± 19.83 months after surgery. Hearing of these patients significantly improved from 73.87 ± 21.40 dB preoperatively to a mean pure-tone average of 41.56 ± 18.87 dB 1 year (p = 0.0008) and 34.58 ± 2.92 dB 3 years after surgery (p = 0.0157). Speech recognition significantly recovered from 13.33 ± 25.41% to 58.93 ± 27.61% 1 year (p = 0.0012) and 51.67 ± 28.58% 3 years postoperatively (p = 0.0164). Regardless of tumor histopathology, CI is an effective option to restore patients' hearing after translabyrinthine tumor surgery. After CI, patients hearing can be restored over a long-term period of a minimum of 3 years post-surgery. Furthermore, eABR proves to be a practical tool to evaluate CN function and screen for patients eligible for CI.

Auditory brainstem response audiometry in tauopathy mouse model of human Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder in which changes in hearing sensitivity precede cognitive decline. Despite a well-known link between dementia and hearing loss, few AD model mouse lines have hearing characterized. We screened for hearing loss using auditory brainstem responses (ABR) in young (3-4 months) and aging (9-10 months) mice with a P301S tauopathy (PS19 mice). Compared to wild types, aging PS19 mice did not show accelerated hearing loss but did show latency differences in centrally generated ABR waveform components. These results suggest that tauopathy causes mild central auditory dysfunction in the absence of overt hearing loss.

"To implant or not to implant": electrically evoked auditory brainstem response audiometry for decision-making in vestibular schwannoma resection with CI.

Vestibular schwannomas (VS) are often associated with debilitating hearing loss. Therefore, preservation and rehabilitation of hearing have become major therapeutic goals of VS management. Recently, cochlear implantation (CI) has been established as an effective treatment option for VS-associated hearing loss. Nevertheless, the integrity and proper function of the cochlear nerve must be evaluated before conducting CI to ensure optimal CI outcomes. Various methods to determine cochlear nerve integrity and functionality have emerged in the last few years. Of these, the use of electrically evoked auditory brainstem response audiometry (eABR) in particular has been proven to be ameaningful tool for monitoring cochlear nerve health during VS surgery. Here, the cochlear nerve can be electrically stimulated using an intracochlear test electrode before, during, and after tumor extirpation. Subsequently, the resulting brainstem responses can be measured and interpreted accordingly to obtain direct information on the cochlear nerve function. This allows for continuous monitoring of cochlear nerve function throughout the course of VS surgery and aids in the decision-making for CI candidacy. Finally, in the case of preserved brainstem responses, CI can be performed instantly after VS extirpation. This simultaneous approach offers several advantages over two-staged procedures and has been shown to be an efficient and safe procedure for restoring hearing after VS removal.

4-octyl itaconate alleviates cisplatin-induced ferroptosis possibly via activating the NRF2/HO-1 signalling pathway.

Ferroptosis, characterized by iron-dependent lipid reactive oxygen species (ROS) accumulation, plays a pivotal role in cisplatin-induced ototoxicity. Existing research has suggested that in cisplatin-mediated damage to auditory cells and hearing loss, ferroptosis is partially implicated. 4-Octyl itaconate (4-OI), derived from itaconic acid, effectively permeates cell membranes, showcasing potent anti-inflammatory as well as antioxidant effects in several disease models. Our study aimed to investigate the effect of 4-OI on cisplatin-induced ferroptosis and the underlying molecular mechanisms. The survival rates of HEI-OC1 cells and mice cochlea hair cells were measured by CCK8 and immunofluorescence, respectively. The auditory brainstem response (ABR) audiometry was used to detect changes in hearing thresholds in mice before and after treatment. Levels of ROS were evaluated by DCFH-DA. Real-time PCR quantified inflammatory cytokines TNF-α, IL-6 and IL-1β. Network Pharmacology and RNA sequencing (RNA-seq) analysis of the potential mechanism of 4-OI resistance to cisplatin-induced ferroptosis. The expressions of ferroptosis-related factors (GPX4, SLC7A11 and PTGS2) and important antioxidant factors (NRF2, HO-1, GCLC and NQO1) were tested by real-time PCR, Western blot and immunofluorescence. Results demonstrated cisplatin-induced significant ROS and inflammatory factor release, reduced NRF2 expression, hindered nuclear translocation and activated ferroptosis. Pretreatment with 4-OI exhibited anti-inflammatory and antioxidant effects, along with resistance to ferroptosis, ultimately mitigating cisplatin-induced cell loss. In the present study, we show that 4-OI inhibits cisplatin-induced ferroptosis possibly through activation of the NRF2/HO-1 signalling pathway, thereby exerting a protective effect against cisplatin-induced damage to auditory cells, and providing a new therapeutic strategy for cisplatin-induced hearing loss.

Magnetic resonance spectroscopy and auditory brain-stem response audiometry as predictors of bilirubin-induced neurologic dysfunction in full-term jaundiced neonates

The purpose of this research was to define the functions of MRS and ABR as predictors of bilirubin-induced neurologic dysfunction (BIND) in full-term neonates who required intervention (phototherapy and/or exchange transfusion). This prospective cohort study was done at the NICU of Tanta University Hospitals over a 2-year duration. Fifty-six full-term neonates with pathological unconjugated hyperbilirubinemia were divided according to MRS and ABR findings into 2 groups: group (1) included 26 cases with mild acute bilirubin encephalopathy (BIND-M score 1–4). Group (2) included 30 cases with neonatal hyperbilirubinemia only. In addition, 20 healthy neonates with similar ages were employed as the controls. When compared to group 2 and the control group, group 1’s peak-area ratios of NAA/Cr and NAA/Cho were found to be significantly reduced (P < 0.05). As compared to group 2 and the control group, group 1’s Lac/Cr ratio was significantly greater (P < 0.05), but the differences were not significant for group 2 when compared to the control group. Waves III and V peak latencies, I–III, and I–V interpeak intervals were significantly prolonged in group 1 in comparison to group 2 and controls (P < 0.05) with no significant difference between group 2 and control group. Conclusion: When the symptoms of ABE are mild and MRI does not show any evident abnormalities, MRS and ABR are helpful in differentiating individuals with ABE from patients with neonatal hyperbilirubinemia. Trial registration: ClinicalTrials.gov, Identifier: NCT06018012.What is Known:• MRS can be used as a diagnostic and prognostic tool for the differential diagnosis of patients with acute bilirubin encephalopathy, from patients with neonatal hyperbilirubinemiaWhat is New:• ABR is a useful diagnostic and prognostic tool in the care and management of neonates with significantly raised bilirubin. It can be used as early predictor of acute bilirubin encephalopathy in the earliest stage of auditory damage caused by bilirubin.

Comparative study of Automated Auditory Brainstem Response (AABR) and Brainstem Evoked Response Audiometry (BERA) for Hearing Loss Detection in High Risk Infants delivered in Dhulikhel Hospital

Background &amp; Objective: Brainstem evoked response audiometry (BERA) is most specific and sensitive test for brain stem dysfunction. It is most important objective method for evaluating peripheral auditory system in neonates, infants, sedated and comatose patients and other person who doesn’t understand the language. Objective of the study was to evaluate correlation BERA with other audiological tests in different types of hearing loss. Material and Methods: This was a hospital based retrospective observational analytic study that used a cross-sectional approach. The sampling used was consecutive sampling until the minimum size fulfilled from 1st September 2021 to 30th September 2022. All high-risk infants aged 0–3 months who suffer from asphyxia, sepsis, LBW, premature, and hyperbilirubinemia, the baby was stable and transportable, the patient’s parents were willing to participate were taken. Results: Out of 46 high risk infants of 0 - 3 months, male:female ratio of 1.7:1 with mean age of 31 days, the most common high risk factor was low birth weight and hyperbilirubinemia i.e 23(50%). 64% of infants were pass in AABR 2nd test in comparison to 71% pass in BERA test. Conclusion: There was no difference between AABR and BERA results for HL detection in high-risk infants at NICU.

Salidroside Attenuates Cisplatin-Induced Ototoxicity: An Experimental Study In Vitro and In Vivo

Oxidative damage to hair cells is the major cause of ototoxicity induced by cisplatin (cis)-based chemotherapy. In this study, we aimed to assess how salidroside (SAL) protected cochlear explants (CEs) and HEI-OC1 cell lines against cis-induced ototoxicity and reduced relative hearing loss in mouse models. Furthermore, the protective mechanism of the Nrf2/ARE pathway was investigated. Cell Counting Kit-8 was used to measure the viability of HEI-OC1 cells. Flow cytometry and the TUNEL assay were used to evaluate cell apoptosis. Flow cytometry was used to measure intracellular reactive oxygen species (ROS). Immunofluorescence staining determined the changes in mitochondrial membrane potential (ΔΨm). Western blot was used to measure the levels of caspase-3 and Nrf-2. An analysis of Nrf2 and target gene levels of expression was conducted using qRT-PCR. Hearing was monitored using auditory brainstem response audiometry. In cochlear explants, SAL inhibits cis-induced apoptosis of HEI-OC1 cells and decreased hair cell apoptosis. SAL inhibited cis-induced apoptosis by lowering intracellular ROS, preserving mitochondrial function, and reducing caspase-3 expression. Moreover, auditory cells were protected from the toxic effects of cis by the Nrf2-ARE pathway after treatment with SAL. In Vivo, SAL could protect against cis-induced hearing loss, and the use of the PLGA-poloxamer nanohydrogel as a carrier increased the protection efficiency of SAL. Through its ability to reduce oxidative stress, SAL could protect auditory cell lines from cis-induced apoptosis In Vitro and attenuate cis-induced hearing loss In Vivo. Nano-based drug delivery can improve the protection efficiency of SAL. Further research should be conducted on the antioxidant capacity of SAL and its use in ototoxicity.

Functional Outcome After Simultaneous Vestibular Schwannoma Resection and Cochlear Implantation With Intraoperative Cochlear Nerve Monitoring.

Electrically evoked auditory brainstem response audiometry has emerged as a suitable option to intraoperatively assess cochlear nerve function during vestibular schwannoma resection. This study aimed to analyze the functional outcome and implant usage of patients with preserved auditory nerve responses after simultaneous translabyrinthine schwannoma resection and cochlear implantation. Prospective study. Tertiary referral center. Patients with unilateral sporadic vestibular schwannoma underwent translabyrinthine tumor resection. Intraoperatively, electrically evoked auditory brainstem response audiometry was performed before and after tumor removal. Cochlear implantation was carried out if positive responses were detected after tumor removal indicating cochlear nerve function. Postoperatively, patients were biannually followed-up to assess aided sound field audiometry and word recognition as well as implant usage. Overall, 26 patients with vestibular schwannoma underwent translabyrinthine schwannoma resection. Out of these patients, 15 had positive cochlear nerve responses after tumor removal and concurrently received a cochlear implant. In 13 patients with histologically confirmed vestibular schwannoma, hearing improved by 23.7 ± 33.2 decibels and word recognition by 25.0 ± 42.4% over a mean follow-up period of 18 months. Overall, 12 included patients were regular cochlear implant users. Patients with vestibular schwannoma can benefit substantially from cochlear implantation. Intraoperative assessment of cochlear nerve function using electrically evoked auditory brainstem response audiometry can help to better identify individuals eligible for simultaneous vestibular schwannoma resection and cochlear implantation.

The Sensitivity and Specificity of DPOAE (Distortion Product Otoacoustic Emission) Compared with ABR (Auditory Brain Stem Response Audiometry) in Neonatal Hearing Screening

The Sensitivity and Specificity of DPOAE (Distortion Product Otoacoustic Emission) Compared with ABR (Auditory Brain Stem Response Audiometry) in Neonatal Hearing Screening

Preventive Effects of Ginkgo-Extract EGb 761® on Noise Trauma-Induced Cochlear Synaptopathy.

Noise trauma-induced loss of ribbon synapses at the inner hair cells (IHC) of the cochlea may lead to hearing loss (HL), resulting in tinnitus. We are convinced that a successful and sustainable therapy of tinnitus has to treat both symptom and cause. One of these causes may be the mentioned loss of ribbon synapses at the IHC of the cochlea. In this study, we investigated the possible preventive and curative effects of the Ginkgo biloba extract EGb 761® on noise-induced synaptopathy, HL, and tinnitus development in Mongolian gerbils (Meriones unguiculatus). To this end, 37 male animals received EGb 761® or placebo orally 3 weeks before (16 animals) or after (21 animals) a monaural acoustic noise trauma (2 kHz, 115 dB SPL, 75 min). Animals’ hearing thresholds were determined by auditory brainstem response (ABR) audiometry. A possible tinnitus percept was assessed by the gap prepulse inhibition acoustic startle reflex (GPIAS) response paradigm. Synaptopathy was quantified by cochlear immunofluorescence histology, counting the ribbon synapses of 15 IHCs at 11 different cochlear frequency locations per ear. We found a clear preventive effect of EGb 761® on ribbon synapse numbers with the surprising result of a significant increase in synaptic innervation on the trauma side relative to placebo-treated animals. Consequently, animals treated with EGb 761® before noise trauma did not develop a significant HL and were also less affected by tinnitus compared to placebo-treated animals. On the other hand, we did not see a curative effect (EGb 761® treatment after noise trauma) of the extract on ribbon synapse numbers and, consequently, a significant HL and no difference in tinnitus development compared to the placebo-treated animals. Taken together, EGb 761® prevented noise-induced HL and tinnitus by protecting from noise trauma-induced cochlear ribbon synapse loss; however, in our model, it did not restore lost ribbon synapses.

Circadian Sensitivity of Noise Trauma-Induced Hearing Loss and Tinnitus in Mongolian Gerbils.

Noise-induced hearing loss (HL) has a circadian component: In nocturnal mice, hearing thresholds (HT) have a significantly stronger effect to acoustic trauma when induced during the night compared to rather mild effects on hearing when induced during daytime. Here, we investigate whether such effects are also present in diurnal Mongolian gerbils and determined whether trauma-induced HL correlated with the development of a tinnitus percept in these animals. In particular, we investigated the effects of acoustic trauma (2 kHz, 115 dB SPL, 75 min) on HT and tinnitus development in 34 male gerbils exposed either at 9 AM, 1 PM, 5 PM, or 12 PM. HT was measured by acoustic brainstem response audiometry at defined times 1 day before and 1 week after the trauma. Possible tinnitus percepts were assessed behaviorally by the gap prepulse inhibition of the acoustic startle response at defined times 1 day before and 1 week after the trauma. We found daytime-dependent changes due to trauma in mean HT in a frequency-dependent manner comparable to the results in mice, but the results temporally shifted according to respective activity profiles. Additionally, we found linear correlations of these threshold changes with the strength of the tinnitus percept, with the most prominent correlations in the 5 PM trauma group. Taken together, circadian sensitivity of the HT to noise trauma can also be found in gerbils, and tinnitus strength correlates most strongly with HL only when the trauma is applied at the most sensitive times, which seem to be the evening.

Difference in Thresholds Between Auditory Brainstem Response Test and Pure Tone Audiometry by Frequency

Background and Objectives There is no clear standard for the difference in the thresholds of auditory brainstem response (ABR) and pure tone audiometry (PTA) when using ABR to evaluate the reliability of PTA. Therefore, we assessed the difference in the thresholds of ABR and PTA for each frequency. Consequently, we present here the actual difference values between the two tests that can be used as a reference in the clinic.Subjects and Method We retrospectively assessed the audiometry results of 129 ears. Ears in which the hearing thresholds of each frequency continuously declined were classified as the downward group. We compared the average of differences between the two tests by frequency. The differences were compared for each hearing level from 50 dB or higher.Results For all ears, the appropriate range of difference value was ±5 dB at 2 kHz. At 1 kHz, the ABR threshold was 10 dB higher than PTA, and it was 10 dB less than PTA at 4 kHz. In the downward group, the difference value increased by 10 dB at 1 kHz and 4 kHz. In the subgroups at each hearing level, the difference value showed similar results (p&lt;0.05).Conclusion The difference in the threshold, regardless of the severity or tendency of hearing loss, was the smallest at 2 kHz and the range was ±5 dB. ABR was 10 dB higher at 1 kHz and and 10 dB lower at 4 kHz than PTA. In the downward group, the difference at 1 kHz and 4 kHz increased by 10 dB each.

Long-Term Effects of Aircraft Noise Exposure on Vascular Oxidative Stress, Endothelial Function and Blood Pressure: No Evidence for Adaptation or Tolerance Development.

Transportation noise is recognized as an important cardiovascular risk factor. Key mechanisms are noise-triggered vascular inflammation and oxidative stress with subsequent endothelial dysfunction. Here, we test for adaptation or tolerance mechanisms in mice in response to chronic noise exposure. C57BL/6J mice were exposed to aircraft noise for 0, 4, 7, 14 and 28d at a mean sound pressure level of 72 dB(A) and peak levels of 85 dB(A). Chronic aircraft noise exposure up to 28d caused persistent endothelial dysfunction and elevation of blood pressure. Likewise, reactive oxygen species (ROS) formation as determined by dihydroethidium (DHE) staining and HPLC-based measurement of superoxide formation in the aorta/heart/brain was time-dependently increased by noise. Oxidative burst in the whole blood showed a maximum at 4d or 7d of noise exposure. Increased superoxide formation in the brain was mirrored by a downregulation of neuronal nitric oxide synthase (Nos3) and transcription factor Foxo3 genes, whereas Vcam1 mRNA, a marker for inflammation was upregulated in all noise exposure groups. Induction of a pronounced hearing loss in the mice was excluded by auditory brainstem response audiometry. Endothelial dysfunction and inflammation were present during the entire 28d of aircraft noise exposure. ROS formation gradually increases with ongoing exposure without significant adaptation or tolerance in mice in response to chronic noise stress at moderate levels. These data further illustrate health side effects of long-term noise exposure and further strengthen a consequent implementation of the WHO noise guidelines in order to prevent the development of noise-related future cardiovascular disease.

Biallelic p.V37I variant in GJB2 is associated with increasing incidence of hearing loss with age

PurposeThis study aimed to quantitatively assess the incidence of hearing loss in relation to age in individuals with biallelic p.V37I variant in GJB2. MethodsPopulation screening of the biallelic p.V37I variant was performed in 30,122 individuals aged between 0 and 97 years in Shanghai. Hearing thresholds of the biallelic p.V37I individuals and the controls were determined by click auditory brainstem response or pure tone audiometry. ResultsBiallelic p.V37I was detected in 0.528% (159/30,122) of the subjects. Of the biallelic p.V37I newborns, 43.91% (18/41) passed their distortion-product otoacoustic emissions–based newborn hearing screening or had hearing thresholds lower than 20 decible above normal hearing level. The older newborns had elevated hearing thresholds, with increasing incidence of 9.52%, 23.08%, 59.38%, and 80.00% for moderate or higher grade of hearing loss in age groups of 7 to 15 years, 20 to 40 years, 40 to 60 years, and 60 to 85 years, respectively. Their hearing deteriorated at a rate of 0.40 dB hearing level per year on average; males were more susceptible, and deterioration occurred preferentially at higher sound frequencies. ConclusionThe biallelic p.V37I variant is associated with steadily progressive hearing loss with increasing incidence over the course of life. Most of the biallelic p.V37I individuals may develop significant hearing loss in adulthood and, can benefit from early diagnosis and intervention through wide-spread genetic screening.

Targeting Autophagy Induction as A possible Protective Mechanism by Verapamil Compared to Rapamycin (Sirolimus) Against Gentamicin -Induced Ototoxicity in Guinea Pigs

Background: Ototoxicity is a harmful feature of the cochlea or auditory nerve and sometimes vestibularapparatus. Gentamicin is known to cause irreversible bilateral ototoxicity. Autophagy induction hasbeen proposed as a target for prevention of gentamicin ototoxicity. Aim of the work: to investigate thepossible protective effect of autophagy induction by verapamil compared to rapamycin. Methods: Thisexperiment was conducted on 32 male guinea pigs. At the beginning each animal’s hearing status wasassessed using auditory brainstem response (ABR) audiometry. Then, they were divided into 4 equalgroups: Group 1: control group, Group 2: untreated gentamicin-induced ototoxicity group. Group 3:gentamicin-induced ototoxicity treated concomitantly with rapamycin. Group 4: gentamicin-inducedototoxicity treated concomitantly with verapamil. At the end of the experiment, ABR was repeatedthen the animals were sacrificed, and blood samples were obtained for assaying of reduced glutathioneand malondialdehyde levels. The left cochlea was processed for scanning electron microscope, whilethe right cochlea was processed for histopathology and LC3-II immunohistochemistry. Results:Verapamil revealed superiority compared to rapamycin proved by significant improvement in ABR,histopathological results, in addition to its antioxidant effect. Conclusion: verapamil could be suggestedas a potential therapeutic approach to decrease gentamicin ototoxicity.

Tinnitus development is associated with synaptopathy of inner hair cells in Mongolian gerbils.

Human hearing loss (HL) is often accompanied by comorbidities like tinnitus, which is affecting up to 15% of the adult population. Rodent animal studies could show that tinnitus may not only be a result of apparent HL due to cochlear hair cell damage but can also be a consequence of synaptopathy at the inner hair cells (IHCs) already induced by moderate sound traumata. Here, we investigate synaptopathy previously shown in mice in our animal model, the Mongolian gerbil, and relate it to behavioral signs of tinnitus. Tinnitus was induced by a mild monaural acoustic trauma leading to monaural noise induced HL in the animals, quantified by auditory brainstem response (ABR) audiometry. Behavioral signs of tinnitus percepts were detected by measurement of prepulse inhibition of the acoustic startle response in a gap-noise paradigm. Fourteen days after trauma, the cochleae of both ears were isolated, and IHC synapses were counted within several spectral regions of the cochlea. Behavioral signs of tinnitus were only found in animals with IHC synaptopathy, independent of type of HL. On the other hand, animals with apparent HL but without behavioral signs of tinnitus showed a reduction in amplitudes of ABR waves I&II but no significant changes in the number of synapses at the IHC. We conclude-in line with the literature-that HL is caused by damage to the IHC or by other reasons but that the development of tinnitus, at least in our animal model, is closely linked to synaptopathy at the IHC.

A novel scoring system based on small vestibular schwannomas to determine consideration for cochlear implantation.

Simultaneous translabyrinthine tumor resection and cochlear implantation is a promising treatment method with hearing rehabilitation for sporadic vestibular schwannomas. Size of vestibular schwanomma, distance to modiolus, residual hearing and promontory stimulation electrical brainstem response audiometry are important preoperative predictive factors for determining a positive post tumour resection electrically evoked auditory brain stem response. The presence of an electrically evoked auditory brain stem response with an intracochlear test electrode after tumour resection was used to determine whether a patient received a cochlear implant Positive electrically evoked auditory brain stem responses measured with an intracochlear test electrode after tumour resection seem to correlate well with auditory perception with a cochlear implant.

The use of melatonin for auditory brainstem response audiometry in children with comorbidities.

In this study, the efficacy and feasibility of melatonin in young children with and without comorbidities, undergoing auditory brainstem response audiometry (ABR) was evaluated. The aim of this study was primarily to evaluate the use of melatonin for ABR investigations in children with comorbidities. Second, the efficacy of melatonin was evaluated based on several factors like sleep-onset latency, sleep duration, frequency of awakenings as well as adverse events. Click-induced ABR tests were performed at the outpatient clinic between January, 2018 and August, 2020. Investigations were considered successful when binaural testing was completed. A dose of melatonin depending on age, 5mg for children younger than 6years and 10mg if older than 6years, was administered after placement of electrodes. 131 children were included in this study. 87% of all ABR investigations were performed successfully. Comorbidities such as neurodevelopmental disorders or developmental delays were present in 70% of all children. There was no significant difference in age (p = 0.36) or gender (p = 0.97) between the success and failed group. In addition, comorbidities were equally distributed between both groups. Mean sleep duration was 38 (SD 21) min and sleep-onset latency was 28 (SD 20) min No adverse events were documented. Melatonin is effective for ABR examinations in infants and children with and without comorbidities. Furthermore, it allows for sequential testing in those at risk for progressive hearing loss. Clear instructions to caregivers and expertise of audiologists are a prerequisite for optimal outcomes.

Towards effective assessment of normal hearing function from ABR using a time-variant sweep-tone stimulus approach

Objective. The auditory brainstem response (ABR) audiometry is a means of assessing the functional status of the auditory neural pathway in the clinic. The conventional click ABR test lacks good neural synchrony and it mainly evaluates high-frequency hearing while the common tone-burst ABR test only detects hearing loss of a certain frequency at a time. Additionally, the existing chirp stimuli are designed based on average data of cochlear characteristics, ignoring individual differences amongst subjects. Approach. Therefore, this study designed a new stimulus approach based on a sweep-tone concept with a time variant and spectrum characteristics that could be customized based on an individual’s cochlear characteristics. To validate the efficiency of the proposed method, we compared its performance with the click and tone-bursts using ABR recordings from 11 normal-hearing adults. Main results. Experimental results showed that the proposed sweep-tone ABR achieved a higher amplitude compared with those elicited by the click and tone-bursts. When the stimulus level or rate was varied, the sweep-tone ABR consistently elicited a larger response than the corresponding click ABR. Moreover, the sweep-tone ABR appeared earlier than the click ABR under the same conditions. Specifically, the mean wave V peak-to-peak amplitude of the sweep-tone ABR was 1.3 times that of the click ABR at 70 dB nHL (normal hearing level) and a rate of 20 s−1, in which the former saved 40% of test time. Significance. In summary, the proposed sweep-tone approach is found to be more efficient than the traditional click and tone-burst in eliciting ABR.

Comparison Results of Automated Auditory Brainstem Response and Brainstem Evoked Response Audiometry for Hearing Loss Detection in High-risk Infants

BACKGROUND: Brainstem evoked response audiometry (BERA) is not widely used for hearing screening because it is considered less practical; however, it is often used for diagnostics. Since the founding of automated auditory brainstem response (AABR), it often uses because it is more practical, has a high sensitivity and specificity in early detection of hearing loss (HL) in high-risk infants.&#x0D; AIM: The objective of the study was to determine the differences results of AABR and BERA for HL detection in high-risk infants at neonatal intensive care unit (NICU).&#x0D; METHODS: The study was conducted from November 2014 to September 2015 with consecutive sampling. The subjects were high-risk infants treated in the NICU room of the Neonatology Division at Dr. Soetomo General Hospital Surabaya and examined using AABR or BERA to determine the existence of HL.&#x0D; RESULTS: BERA results obtained normal (negative) as many as 28 ears (73.68%) and not normal (positive) as many as 10 ears (26.32%). AABR results obtained pass (negative) as many as 23 ears (60.53%) and refer (positive) as many as 15 ears (39.47%). Detection of HL in high-risk infants in NICU with AABR obtained 40% of sensitivity and 60.71% of specificity, 26.67% of positive prediction (NPP), 73.91% of negative predictive value (NPN), 55.26% of accuracy, 39.29% of false positive error rate, and 60% of false negative error rate. The comparative test of Wilcoxon signed-rank between the results of AABR and BER obtained p = 0.236.&#x0D; CONCLUSIONS: There was no difference between AABR and BERA results for HL detection in high-risk infants at NICU.