Auditory steady-state response and auditory brainstem response thresholds in children

The inclusion of the auditory steady-state response (ASSR) into test-batteries for objective audiometry has allowed for clinical comparisons with the most widely used procedure, the auditory brainstem response (ABR). The current study describes ASSR and ABR thresholds for a group of infants and young children with various types and degrees of hearing loss. A sample of 48 subjects (23 female) with a mean age of 2.8 ± 1.9 years SD were assessed with a comprehensive test-battery and classified according to type and degree of hearing loss. Thresholds were determined with a broadband click-evoked ABR and single frequency ASSR evoked with continuous tones (0.25–4 kHz) amplitude modulated (67–95 Hz). Mean difference scores (±SD) between the ABR and high frequency ASSR thresholds were 9.8 (±11), 3.6 (±12) and 10.5 (±12) dB at 1, 2 and 4 kHz, respectively. An ASSR mean threshold for 2–4 and 1–4 kHz compared to the ABR threshold revealed an average difference of 7 (±9) and 7.9 (±8) dB, respectively. The overall correlation between the ABR and ASSR thresholds was highest for the mean ASSR thresholds of 2–4 and 1–4 kHz (r = 0.92 for both conditions). Correlations between the ABR and individual ASSR frequencies were slightly less (0.82–0.86). The average of the 2–4 kHz ASSR thresholds correlated best with the click-evoked ABR for all categories of hearing loss except for the sensorineural hearing loss category for which the 1–4 kHz ASSR average was better correlated to ABR thresholds. Findings demonstrate the reliability of verifying high frequency ASSR thresholds with a click-evoked ABR as an important cross-check in infants for whom behavioural audiometry may not be possible.     

Effectiveness of Ginkgo biloba diterpene lactone in the treatment of sudden sensorineural hearing loss

PurposeTo evaluate the effectiveness of systemic Ginkgo biloba diterpene lactone therapy for sudden sensorineural hearing loss.MethodsThis retrospective review investigated 56 patients with unilateral sudden sensorineural hearing loss. Among them, 26 patients received conventional therapy (group C, intravenous methylprednisolone), and 30 received conventional therapy supplemented with Ginkgo biloba diterpene lactone (group G). Pure tone audiometry was measured before treatment and 1 month after treatment. The average pure tone audiometry gain, pure tone audiometry gain at each frequency, pure tone audiometry gain according to initial hearing loss, and rate of effectiveness were defined as functionally relevant recovery of hearing and compared between the two groups.ResultsThe average pure tone audiometry gain was significantly greater in group G (20.6 ± 15.1 dB) than in group C (11.9 ± 13.3 dB) (p = 0.025), with similar trends at 250, 1 k, and 8 k Hz. In the subgroup of patients with profound hearing loss (initial pure tone audiometry >70 dB), hearing gain was significantly higher in group G (26.7 ± 14.4 dB) than in C (5.5 ± 9.0 dB) (p = 0.034). In the mild-moderate hearing loss subgroup (initial pure tone audiometry ≤70 dB), the pure tone audiometry gain did not differ significantly (group G: 18.4 ± 14.3 dB; group C: 13.0 ± 13.4 dB) (p = 0.209). The overall rate of effectiveness was 73.3% and 57.7% in groups G and C, respectively; however, the difference was statistically insignificant (p = 0.218).ConclusionsCompared with conventional therapy alone, supplementary systemic administration of Ginkgo biloba diterpene lactone to treat sudden sensorineural hearing loss could improve hearing recovery, especially, in patients with profound hearing loss.     

60例军校男女学员ASSR测试研究

目的旨在观察正常年轻人多频稳态诱发电位（ASSR）测试的正常值特点。方法对60例第一军医大学学员行ASSR、ABR和电测听测试，比较男．女及左、右耳测试值的差异。结果ASSR0．5kHz、1kHz、2kHz、4kHz测试值均数与纯音听闻均数各频率的差值分别为13．86dBHL、14．63dBHL、13．06dBHL．15．28dBHL；ASSR0．5kHz、1kHz、2kHz、4KHz测试值均数与ABRV波反应阈的差值分别为6．14dBHL、5．37dBHL、6．94dBHL、4．72dBHL；男、女学员ASSR测试值比较无显著性差异（P〉0．05）。结论ASSR正常值不受性别．耳别的影响；用ASSR测试值来推断预估纯音听阈．ABRV波反应阈要综合考虑各频率的差值。     

Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects

IntroductionAuditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults.AimCompare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects.Materials and methodsIn this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal pure-tone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated.ResultsThe mean difference between PT and ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency.ConclusionASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.© 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.     

多频稳态诱发电位评估中度感音神经性聋儿童的应用

目的探讨多频稳态听觉诱发电位评估儿童中度感音神经性聋的可靠性。方法所有患者经纯音测听（PTA）检查筛选出中度感音神经性聋30例5～6岁儿童（共40耳），然后口服10％水合氯醛镇静睡眠后，行多频稳态听觉诱发电位（ASSR）检测，其阈值与纯音听阂阈值进行比较，分析不同频率处听力阈值分布情况及其相关性。结果分别比较语言频率ASSR阂值与纯音听闽阈值，结果显示，0．5kHz处相关性较差，其差值为2-18dB，而在4kHz处相关性最好。结论可以应用多频稳态听觉诱发电位评估中度感音神经性聋儿童的听力阈值，但需要注意0．5kHz处的相关性差异。     

Auditory steady-state responses for estimating moderate hearing loss

The auditory steady-state response (ASSR) has gained popularity as an alternative technique for objective audiometry but its use in less severe degrees of hearing loss has been questioned. The aim of this study was to investigate the usefulness of the ASSR in estimating moderate degrees of hearing loss. Seven subjects (12 ears) with moderate sensorineural hearing loss between 15 and 18 years of age were enrolled in the study. Forty-eight behavioural and ASSR thresholds were obtained across the frequencies of 0.5, 1, 2, and 4 kHz. ASSR thresholds were determined using a dichotic multiple frequency recording technique. Mean threshold differences varied between 2 and 8 dB (±7–10 dB SD) across frequencies. The highest difference and variability was recorded at 0.5 kHz. The frequencies 1–4 kHz also revealed significantly better correlations (0.74–0.88) compared to 0.5 kHz (0.31). Comparing correlation coefficients for behavioural thresholds less than 60 and 60 dB and higher revealed a significant difference. Eighty-six percent of ASSR thresholds corresponded within 5 dB of moderate to severe behavioural thresholds compared to only 29% for mild to moderate thresholds in this study. The results confirm that the ASSR can reliably estimate behavioural thresholds of 60 dB and higher, but due to increased variability, caution is recommended when estimating behavioural thresholds of less than 60 dB, especially at 0.5 kHz.     

Comparison of auditory steady-state responses and auditory brainstem responses in audiometric assessment of adults with sensorineural hearing loss

Objective

Many of the medico-legal patients who claimed compensation may exaggerate hearing loss that varies in degree, nature, and laterality. The purpose of this study was to investigate whether Auditory Steady-State Response (ASSR) could be used to predict the hearing level of adults, and whether ASSR could become a better testing method than Auditory brainstem response (ABR) in audiometric assessment of adults with sensorineural hearing loss.

Methods

This was a prospective study, which was conducted in a tertiary referral hospital. From January to June 2007, 142 subjects (284 ears) with varying degrees of sensori-neural hearing impairment were included in this study. Four commonly used frequencies (500, 1000, 2000, 4000 Hz) were evaluated. All subjects received pure-tone audiometry, multi-channel ASSR, and ABR tests for threshold measurement. The correlation of pure tone thresholds with ASSR and ABR thresholds were assessed.

Results

Between multi-channel ASSR and pure tone thresholds, a difference of less than 15 dB was found in 71% while a difference of less than 25 dB was found in 89% of patients. The correlation coefficient (r) of multi-channel ASSR and pure tone thresholds were 0.89, 0.95, 0.96, and 0.97 at 500, 1000, 2000, and 4000 Hz, respectively. The strength of the relationship increased with increasing frequency. On the other hand, between ABR and pure-tone thresholds, a difference of less than 15 dB was found in 31%; a difference of less than 25 dB was found in 62% of patients. The r correlation value for ABR and pure tone thresholds was 0.83.

Conclusion

ASSR is a more reliable test for the accurate prediction of auditory thresholds than ABR. It can be a powerful and convenient electro-physiologic examination tool for clinically assessing of adults with sensorineural hearing loss.     

成人感音神经性聋的听觉稳态反应反应阈与纯音听阈

目的探讨成人感音神经性聋的听觉稳态反应（auditory steady-state responses,ASSR）反应阈与纯音听阈的关系。方法选择中国医科大学附属一院耳鼻咽喉科门诊感音神经性聋的成人患者,分别进行纯音听力测试、ASSR检查,比较ASSR在0.5、1、2、4 kHz频率处的反应阈与纯音听阈的相关性及按听力损失程度比较两者的差值。结果 ASSR反应阈与纯音听阈在各频率处的相关系数分别为0.840、0.905、0.886、0.924;随着感音神经性听力损失的加重二者的差值明显缩小。随着频率的增加,两者的差值明显缩小。结论成人感音神经性聋ASSR反应阈与纯音听阈有显著相关性,随着听力损失的加重,ASSR反应阈愈接近纯音听阈,ASSR作为成人感音神经性聋听力定量诊断的客观方法有很大的临床应用价值。     

Using multi-stimulus auditory steady state response to predict hearing thresholds in high-risk infants

The purpose of this study was to investigate whether multi-stimulus auditory steady-state responses were capable of estimating hearing thresholds in high-risk infants. A retrospective chart review study. Three tertiary referral centers. Infants born between January 2004 and December 2006 who met the criteria for risk factors of congenital hearing loss were enrolled in the study. While under sedation, the multi-stimulus auditory steady-state response was used to determine multi-channel auditory steady-state response thresholds for high-risk infants younger than 13 months. Conditioned play audiometry was then applied to these children at 23–48 months of age to obtain pure tone audiograms. Auditory steady-state response thresholds and pure tone thresholds were then compared. A total of 249 high-risk infants were enrolled in the study. 39 infants were lost during follow-up. The remaining 216 infants completed both examinations. The Pearson correlation coefficients (r) between the ASSR levels and pure tone thresholds were 0.88, 0.94, 0.94 and 0.97 at 500, 1,000, 2,000 and 4,000 Hz, respectively. The strength of the relationship between the auditory steady-state responses and pure tone thresholds increased with more severe degrees of hearing loss and higher frequencies. We conclude that initial multichannel ASSR thresholds measured under sedation are highly correlated with pure tone thresholds obtained 2 or 3 years later. ASSR can be used to predict the frequency-specific hearing thresholds of high-risk infants and can provide information for early hearing intervention.     

自动数字听力计健听儿童测定初探

目的探讨8~18岁健听儿童使用自动听力计的可行性及有效性。方法采用标准听力计和自动数字听力计,在隔音室中采集30名8~18岁健听儿童0.5、1、2、4 kHz的听阈,记录两种测试所用时间。结果8~18岁健听儿童自动测听气导听阈14.21±2.97 dB HL,骨导听阈13.38±2.98 dB HL;标准听力计气导听阈12.58±2.53 dB HL,骨导听阈11.65±2.26 dB HL,两者听阈比较无统计学差异(P>0.05)。不同频率下阈值比较显示,0.5 kHz气导听阈比较无统计学差异(P>0.05),1、2、4 kHz气导听阈比较有统计学差异(P<0.05);0.5、1、2、4 kHz骨导听阈比较有统计学差异(P<0.05)。自动测听平均测听时间为13.76±3.66分,标准听力计平均测听时间为14.15±3.21分,两者比较无统计学差异(P>0.05)。结论8~18岁儿童使用自动听力计可检测出可靠有效的听力阈值。     

Sensorineural hearing dysfunction after discharge from critical care in adults: A retrospective observational study

BackgroundPatients undergoing intensive care are exposed to risk factors for hearing impairment. This study assessed the worse changes in pure tone average (PTA) thresholds after intensive care and identified the factors associated with worse hearing function.MethodsWe conducted a single-centre retrospective study, and included adult patients admitted to the intensive care unit (ICU) of Kurashiki Central Hospital between January 2014 and September 2019, who had regular pure tone audiometry performed before and after ICU admission. Correlations between changes in PTA threshold and patient characteristics, were evaluated. The included ears were classified as those with worse hearing (>10 dB increase in the PTA threshold) and those without worse hearing, and the baseline characteristics were compared.ResultsDuring the study period, 125 ears of 71 patients (male:female ratio, 35:36; mean age, 72.5 ± 12.3 years) met the eligibility criteria. Age, sex, and the use of furosemide were not correlated with changes in PTA threshold. Univariate analysis showed that ears with worse hearing were associated with a lower serum platelet count than ears without worse hearing (153 ± 85 × 10⁹/L vs. 206 ± 85 × 10⁹/L, respectively; P = 0.010), and the rate of planned ICU admission (elective surgery) was higher in the worse hearing group (57.1% vs. 28.8%, respectively; p = 0.011).ConclusionsAge, sex, and the use of furosemide did not have adversely affect hearing function. Low serum platelet count and planned admission appear to be risk factors for worse hearing.     

Tone-evoked brainstem responses and auditory steady state responses to 40hz and 80hz amplitude modulated stimuli with different frequencies — a comparative study

Abstract  Tone burst evoked auditory brainstem responses and auditory steady state responses with 40 or > 80 Hz modulation can be used to determine frequency specific threshold. Aim  The present study was taken up to check for the efficacy of estimating hearing thresholds by tone burst ABR and ASSR. The frequency effect (low, mid and high) on estimating the threshold was also focused upon. Methods  20 normal hearing adults (40 ears) in the age range of 16 to 30 years participated in the study. The pure tone audiometry and immittance was initially done. Subsequently, tone-burst ABR, 80Hz ASSR and 40Hz ASSR to estimate the threshold with three frequencies 500Hz (low), 2000Hz (mid) and 4000Hz (high) was done. The data was analyzed statistically using pair sample t-test. Results  ASSR threshold for 80Hz and 40Hz was almost comparable. ASSR was superior to estimate the threshold than tone-burst ABR. For the low frequency the discrepancy between the behavioral threshold and frequency-specific evoked audiometry was more when compared to mid and high frequency. Conclusion  Present study showed that steady-state responses were efficient means of threshold detection than visual detection of ABR wave-V. In awake adult subjects, 40Hz and 80Hz amplitude modulated produced similar results. For the threshold estimation ASSR was better than tone-burst ABR.     

Objective frequency-specific hearing thresholds definition for medicolegal purposes in case of occupational NIHL: ASSR outperforms CERA

Audiological use of the 40 Hz-ASSR (auditory steady state responses) could be valuable for objectively estimating the frequency-specific threshold in adults undergoing an expertise examination for medicolegal and/or compensation purposes. The present prospective study was set up to clarify the relationship between the thresholds obtained by cortical evoked response audiometry (CERA) and by 40 Hz-ASSR, in the same ears, within a large homogeneous sample of 164 subjects (328 ears) with NIHL and well documented exposure to noise. All these subjects claimed financial compensation for occupational NIHL, and there was a suspicion of exaggeration of the reported NIHLs. ASSR thresholds show a good correlation with the CERA thresholds. However, a systematic shift is noticed, ASSR thresholds being on average (1–2 – 3 kHz) 4.38 dB lower (i.e. showing less hearing loss) than CERA thresholds. Moreover, the binaural multiple ASSR technique allows a considerable time gain when compared to the CERA.     

感音神经性聋成人不同刺激声ASSR反应阈与纯音听阈的相关性分析

目的探讨调制声听性稳态反应(ASSR)、 CE-Chirp ASSR用于评估感音神经性聋成人客观听力的价值。方法对78例(131耳)感音神经性聋成人同时进行纯音听阈和调制声ASSR、 CE-Chirp ASSR测试,比较0.5~4 kHz各频率纯音听阈与调制声ASSR、CE-Chirp ASSR反应阈的相关性及差值。结果 0.5、1、2、4 kHz CE-Chirp ASSR反应阈与纯音听阈的相关系数(分别为0.77、0.73、0.80、0.88)均高于调制声ASSR反应阈与纯音听阈的相关系数(分别为0.64、0.61、0.78、0.84),调制声ASSR、CE-Chirp ASSR反应阈与纯音听阈均具有显著相关性(圴为P<0.01);0.5~4 kHz CE-Chirp ASSR反应阈和纯音听阈的差值(分别为8.09±4.74、10.76±5.86、7.44±7.95、6.11±9.14 dB)均明显小于调制声ASSR反应阈和纯音听阈间的差值(分别为14.31±6.38、13.85±6.25、17.17±6.29、13.58±4.35 dB),差异均有统计学意义(均为P<0.05)。结论 CE-Chirp ASSR快捷可靠,较调制声ASSR能更好地评估感音神经性聋成人的听力。     

Aided auditory steady-state responses in infants

Infants with hearing loss routinely receive hearing aids several months before reliable behavioral responses to amplified sound can be observed. This necessitates objective measures to validate hearing-aid fittings. A single report has demonstrated the use of ASSRs to determine aided thresholds in children but data in young infants is still lacking. The current study explored aided ASSR compared to unaided ASSR thresholds and subsequent behavioral thresholds in a group of six young infants with hearing loss who received hearing aids between three and six months of age. Aided ASSR thresholds were obtained in 83% of frequencies where aided behavioral thresholds were obtained, with a mean threshold difference of 13±13 dB. The aided ASSR-based threshold estimates were within 15 dB of behavioral thresholds in 63% of cases, indicating a moderate correlation (r = 0.55). Comparing aided and unaided ASSR measurements revealed an average functional gain of 36±15 dB. These results indicate that ASSRs can provide the first evidence of robust hearing aid benefit in young infants several months before behavioral responses are observed.     

Establishing normal hearing with the dichotic multiple-frequency auditory steady-state response compared to an auditory brainstem response protocol

OBJECTIVE: To determine the clinical usefulness of the dichotic multiple-frequency (MF) auditory steady-state response (ASSR) technique for estimating normal hearing compared to a 0.5-kHz tone burst and broadband click auditory brainstem response (ABR) protocol in a sample of adults. MATERIAL AND METHODS: A comparative experimental research design was selected in order to compare estimations of normal hearing obtained with the dichotic ASSR technique at 0.5, 1, 2 and 4 kHz with a 0.5-kHz tone burst and broadband click ABR protocol. The recording times required for each procedure were also compared. Normal-hearing subjects (n = 28) were selected according to immittance values within normal limits and pure-tone behavioural thresholds of < 25 dB HL across frequencies. RESULTS: The dichotic MF ASSR estimated normal hearing to be, on average, 30-34 dB HL across the range 0.5-4 kHz. The mean estimate of normal hearing for 0.5 kHz using tone burst ABRs was 30 dB nHL and the mean click ABR threshold was 16 dB nHL, i.e. 14-18 dB better than the ASSR thresholds. The dichotic MFASSR technique recorded 8 thresholds (4 in each ear) in a mean time of 23 min. The ABR protocol recorded 4 thresholds (2 in each ear) in a mean time of 25 min. CONCLUSION: Both the dichotic MF ASSR and ABR protocols provided a time-efficient estimation of normal hearing. There was no significant difference between the tone burst ABR and MF ASSR techniques in terms of estimation of normal hearing at 0.5 kHz. The dichotic MF ASSR technique proved more time-efficient by determining more thresholds in a shorter time compared to the ABR protocol.     

多频稳态诱发电位测试对中重度以下听力损失的评估价值

目的了解多频稳态诱发电位测试在客观听力评价中的准确性。方法对听力正常人、轻度、中度和中重度感音神经性聋的患者共76例耳分别行纯音测听、听觉脑干诱发电位和多频稳态诱发电位测试,对三者阈值进行方差分析、Baye’s准则下多类判别分析。结果由ASSR结果推测客观听力状况所犯的判断错误,在听力正常组,判别符合正确率分别100%,轻度聋组为92.3%,中度聋组判别正确率为88.9%,中-重度聋组判别正确率为83.3%。结论多频稳态诱发电位测试在客观听力评价中有较好的准确率,值得在实际工作中推广应用。     

Threshold prediction using the auditory steady-state response and the tone burst auditory brain stem response: a within-subject comparison

OBJECTIVE: The purpose of this study was to evaluate the accuracy with which auditory steady-state response (ASSR) and tone burst auditory brain stem response (ABR) thresholds predict behavioral thresholds, using a within-subjects design. Because the spectra of the stimuli used to evoke the ABR and the ASSR differ, it was hypothesized that the predictive accuracy also would differ, particularly in subjects with steeply sloping hearing losses. DESIGN: ASSR and ABR thresholds were recorded in a group of 14 adults with normal hearing, 10 adults with flat, sensorineural hearing losses, and 10 adults with steeply sloping, high-frequency, sensorineural hearing losses. Evoked-potential thresholds were recorded at 1, 1.5, and 2 kHz and were compared with behavioral, pure-tone thresholds. The predictive accuracy of two ABR protocols was evaluated: Blackman-gated tone bursts and linear-gated tone bursts presented in a background of notched noise. Two ASSR stimulation protocols also were evaluated: 100% amplitude-modulated (AM) sinusoids and 100% AM plus 25% frequency-modulated (FM) sinusoids. RESULTS: The results suggested there was no difference in the accuracy with which either ABR protocol predicted behavioral threshold, nor was there any difference in the predictive accuracy of the two ASSR protocols. On average, ABR thresholds were recorded 3 dB closer to behavioral threshold than ASSR thresholds. However, in the subjects with the most steeply sloping hearing losses, ABR thresholds were recorded as much as 25 dB below behavioral threshold, whereas ASSR thresholds were never recorded more than 5 dB below behavioral threshold, which may reflect more spread of excitation for the ABR than for the ASSR. In contrast, the ASSR overestimated behavioral threshold in two subjects with normal hearing, where the ABR provided a more accurate prediction of behavioral threshold. CONCLUSIONS: Both the ABR and the ASSR provided reasonably accurate predictions of behavioral threshold across the three subject groups. There was no evidence that the predictive accuracy of the ABR evoked using Blackman-gated tone bursts differed from the predictive accuracy observed when linear-gated tone bursts were presented in conjunction with notched noise. Similarly, there was no evidence that the predictive accuracy of the AM ASSR differed from the AM/FM ASSR. In general, ABR thresholds were recorded at levels closer to behavioral threshold than the ASSR. For certain individuals with steeply sloping hearing losses, the ASSR may be a more accurate predictor of behavioral thresholds; however, the ABR may be a more appropriate choice when predicting behavioral thresholds in a population where the incidence of normal hearing is expected to be high.     

不同程度感音神经性听力损失儿童ASSR、click-ABR反应阈与行为听阈的相关性

目的 探讨不同程度感音神经性听力损失儿童听性稳态反应(ASSR)、短声听性脑干反应(click-ABR)与行为阈值的相关性及在听障儿童听力评估中的价值.方法 回顾性分析2019年1月至2019年12月确诊的46例(92耳)感音神经性听力损失儿童的ASSR、click-ABR及行为听阈结果,其中,轻度听力损失4耳,中度听...     

Relationship between pure tone audiometry and tone burst auditory brainstem response at low frequencies gated with Blackman window

To assess the reliability of Blackman windowed tone burst auditory brainstem response (ABR) as a predictor of hearing threshold at low frequencies. Fifty-six subjects were divided in to three groups (normal hearing, conductive hearing loss, sensorineural hearing loss) after pure tone audiometry (PTA) testing. Then they underwent tone burst ABR using Blackman windowed stimuli at 0.5 kHz and 1 kHz. Results were compared with PTA threshold. Mean threshold differences between PTA and ABR ranged between 11 dB at 0.5 kHz and 14 dB at 1 kHz. ABR threshold was worse than PTA in each but 2 cases. Mean discrepancy between the two thresholds was about 20 dB in normal hearing, reducing in presence of hearing loss, without any differences in conductive and sensorineural cases. Tone burst ABR is a good predictor of hearing threshold at low frequencies, in case of suspected hearing loss. Further studies are recommended to evaluate an ipsilateral masking such as notched noise to ensure greater frequency specificity.