The comparison of auditory behavioral and evoked potential responses (steady state and cortical) in subjects with occupational noise-induced hearing loss

ObjectiveTo define difference scores between PTA, ASSR and CERA thresholds in subjects with occupational NIHL.Design44 subjects undergoing a medico-legal expert assessment for occupational NIHL and fulfilling criteria of reliability were considered. Assessment included: PTA, 40 Hz binaural multiple ASSR and CERA (1-2-3 kHz).ResultsThe respective average difference scores (ASSR - PTA) for 1, 2 and 3 kHz are 13.01 (SD 10.19) dB, 12.72 (SD 8.81) dB and 10.38 (SD 8.19) dB. The average (CERA - ASSR) difference scores are 1.25 (SD 14.63) dB for 1 kHz (NS), 2.73 (SD 13.03) dB for 2 kHz (NS) and 4.51 (SD 12.18) dB for 3 kHz. The correlation between PTA and ASSR (0.82) is significantly stronger than that between PTA and CERA (0.71). In a given subject, PTA thresholds are nearly always lower (i.e., better) than ASSR thresholds, whatever the frequency (1-2-3 kHz) and the side (right – left). A significant negative correlation is found between the difference score (ASSR – PTA) and the degree of hearing loss.ConclusionASSR outperforms CERA in a medicolegal context, although overestimating the behavioral thresholds by 10–13 dB_.     

Prediction of hearing thresholds: comparison of cortical evoked response audiometry and auditory steady state response audiometry techniques

The present study evaluated how well auditory steady state response (ASSR) and tone burst cortical evoked response audiometry (CERA) thresholds predict behavioral thresholds in the same participants. A total of 63 ears were evaluated. For ASSR testing, 100% amplitude modulated and 10% frequency modulated tone stimuli at a modulation frequency of 40Hz were used. Behavioral thresholds were closer to CERA thresholds than ASSR thresholds. ASSR and CERA thresholds were closer to behavioral thresholds at higher frequencies than at lower frequencies. Although predictions based on CERA thresholds are slightly more accurate than ASSR thresholds, the differences may not be clinically significant, particularly when the degree of individual variations is considered. Prediction of hearing thresholds became more accurate when hearing loss increased. Due to variations in prediction across participants, a single correction factor cannot be used. Other factors must be considered in selecting whether to use CERA or ASSR in predicting behavioral thresholds.     

Prediction of hearing thresholds: Comparison of cortical evoked response audiometry and auditory steady state response audiometry techniques

The present study evaluated how well auditory steady state response (ASSR) and tone burst cortical evoked response audiometry (CERA) thresholds predict behavioral thresholds in the same participants. A total of 63 ears were evaluated. For ASSR testing, 100% amplitude modulated and 10% frequency modulated tone stimuli at a modulation frequency of 40Hz were used. Behavioral thresholds were closer to CERA thresholds than ASSR thresholds. ASSR and CERA thresholds were closer to behavioral thresholds at higher frequencies than at lower frequencies. Although predictions based on CERA thresholds are slightly more accurate than ASSR thresholds, the differences may not be clinically significant, particularly when the degree of individual variations is considered. Prediction of hearing thresholds became more accurate when hearing loss increased. Due to variations in prediction across participants, a single correction factor cannot be used. Other factors must be considered in selecting whether to use CERA or ASSR in predicting behavioral thresholds.     

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.     

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.     

Threshold estimation in children using auditory steady-state responses to multiple simultaneous stimuli

OBJECTIVE: It was the aim of this study to explore the use of auditory steady-state response (ASSR) to multiple simultaneous stimuli for threshold estimation in young children. METHOD: The subjects consisted of 40 children, aged from 6 months to 5 years, with variant degrees of sensorineural hearing loss. Simultaneous tonepips (0.5, 1, 2 and 4 kHz) with an amplitude modulated at different rates from 77 to 103 Hz were presented to both ears by insert phones. All children were tested with ASSR and age-appropriate behavioral tests. RESULTS: We found that (1) ASSR thresholds were usually higher than behavioral thresholds with a difference of 8-15 dB, (2) the behavioral thresholds were significantly correlated with ASSR thresholds (p = 0.000), and (3) there was a great difference between ASSR thresholds and behavioral thresholds found in a child with auditory neuropathy. CONCLUSION: Being objective, frequency specific and well correlated with behavioral thresholds, ASSR to multiple simultaneous stimuli was proven to be a good tool to predict behavioral hearing thresholds.     

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.     

听性稳态反应和短声诱发的听性脑干反应在客观听阈评估中的作用

目的探讨听性稳态反应(auditory steady-state responses,ASSR)和短声诱发听性脑干反应(ABR)在感音神经性聋人群客观听阈评估中的作用及其在耳聋鉴定中的价值。方法对感音神经性聋组(35耳)及正常组(22耳)分别进行纯音听阈、ABR及ASSR测试,并记录0.5、1、2及4kHz ASSR反应阈(dBHL)、纯音听阈(dBHL)及ABR反应阈(dBnHL)。结果正常组在0.5、1、2、4kHz的ASSR反应阈与纯音听阈相比差异无统计学意义(P>0.05),ABR反应阈与各频率纯音听阈差异有显著统计学意义(P<0.05);耳聋组各频率ASSR反应阈与纯音听阈差异无统计学意义(P>0.05),ABR反应阈与0.5kHz纯音听阈差异有统计学意义(P<0.05),与1、2、4kHz纯音听阈差异无统计学意义(P>0.05)。结论ASSR与ABR联合测试是临床工作中用于客观听阈评估的有效方法。     

Accuracy of cortical evoked response audiometry in the identification of non-organic hearing loss

Cortical evoked response audiometry (CERA) has been used to identify the presence of a non-organic component in cases where compensation for hearing disability is claimed. This study aims at verifying the magnitude of discrepancy between thresholds estimated by CERA and by pure-tone audiometry (PTA). Results from 204 claimants (408 ears) with reliable PTA and CERA records showed mean discrepancy values between PTA and CERAT of less than 5 dB at high frequencies. Over 83.2% of claimants had a CERAT and PTA threshold discrepancy within 10 dB. Results suggested that while CERA threshold measurement could not accurately predict PTA in all cases, it could still be used as an objective guideline to rule out the presence of a non-organic component in hearing disability compensation claimants.     

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 multiple auditory steady-state responses (80 versus 40 Hz) and slow cortical potentials for threshold estimation in hearing-impaired adults

This study evaluated the use of multiple auditory steady-state responses (ASSRs) and slow cortical potentials (SCPs) to estimate behavioural audiograms in adults for compensation cases. Two groups of 23 subjects were assessed using either 80 Hz or 40 Hz multiple simultaneous tones with carrier frequencies of 0.5, 1.0, 2.0, and 4.0 kHz. SCP thresholds for 0.5, 1.0, and 2.0 kHz were obtained for both groups. Mean evoked potential thresholds (dB HL) minus behavioural pure-tone thresholds (dB HL) difference scores were 5-17 dB for the 80 Hz group, 1-14 dB for the 40 Hz group, and 20-22 dB for the SCPs. Thresholds for 40 Hz ASSR were significantly closer to behavioural thresholds than were 80 Hz or SCP thresholds. SCP and 40 Hz ASSR audiogram estimates were obtained more quickly than the 80 Hz ASSR. Multiple 40 Hz ASSR is the method of choice for evoked potential threshold estimation in adults.     

Comparison of pure tone audiometry and auditory steady-state responses in subjects with normal hearing and hearing loss

The objective of this study is to compare pure tone audiometry and auditory steady-state response (ASSR) thresholds in normal hearing (NH) subjects and subjects with hearing loss. This study involved 23 NH adults and 38 adults with hearing loss (HI). After detection of behavioral thresholds (BHT) with pure tone audiometry, each subject was tested for ASSR responses in the same day. Only one ear was tested for each subject. The mean pure tone average was 9 ± 4 dB for NH group and 57 ± 14 for HI group. There was a very strong correlation between BHT and ASSR measurements in HI group. However, the correlation was weaker in the NH group. The mean differences of pure tone average of four frequencies (0.5, 1, 2, and 4 kHz) and ASSR threshold average of same frequencies were 13 ± 6 dB in NH group and 7 ± 5 dB in HI group and the difference was significant (P = 0.01). It was found that 86% of threshold difference values were less than 20 dB in NH group and 92% of threshold difference values were less than 20 dB in HI group. In conclusion, ASSR thresholds can be used to predict the configuration of pure tone audiometry. Results are more accurate in HI group than NH group. Although ASSR can be used in cochlear implant decision-making process, findings do not permit the utilization of the test for medico-legal reasons.     

Auditory sensitivity in children using the auditory steady-state response

OBJECTIVE: To determine the effectiveness of auditory steady-state response (ASSR) as a measure of hearing sensitivity in young children suspect for significant hearing loss. DESIGN: Within-subject comparisons of click auditory brainstem response (ABR) thresholds and ASSR thresholds. SUBJECTS: The study population comprised 42 children suspect for hearing loss and subsequently referred for hearing assessment using electrophysiologic techniques. MAIN OUTCOME MEASURES: Electrophysiologic threshold responses for click ABR and ASSR stimuli (0.5, 1, 2, and 4 kHz) for right and left ears. RESULTS: Based on ABR and ASSR thresholds, 50% of the subjects demonstrated significant hearing loss in the severe to profound range. In some subjects, ASSRs were present at higher stimulus levels when click ABRs were absent. Significant correlations (P<.05) were found between high-frequency ASSR and click ABR thresholds for this study sample. For some subjects, ASSR findings suggested differences between ears that were not observable from the no-response click ABR results. CONCLUSIONS: Auditory steady-state response testing may provide additional information for children who demonstrate hearing levels in the severe to profound range. This information may be helpful when selecting the ear for cochlear implantation for a young hearing-impaired child. Multiple objective methods, such as ABR and ASSR testing, may be needed to determine accurate hearing sensitivity for young children being considered for sensory devices, and in particular, cochlear implants.     

40-Hz multiple auditory steady-state responses to narrow-band chirps in sedated and anaesthetized infants

Objective

The general consensus to date has been that a stimulus repetition rate of 40 Hz is not appropriate for the recording of auditory steady-state responses (ASSR) in sedated or anaesthetized infants. The aim of this study was to investigate whether reliable 40-Hz ASSR thresholds can be obtained in sedated infants using narrow-band chirp stimuli in the clinical routine.

Methods

40-Hz auditory brainstem responses (ABR) and 40-Hz ASSR were recorded in 34 infants below the age of 48 months under sedation or under general anaesthesia. ABR were evoked by broad-band chirp stimuli with a flat amplitude spectrum. ASSR were recorded simultaneously from both ears with an adaptive multiple stimulus paradigm using four narrow-band chirps centred at 500, 1000, 2000 and 4000 Hz. ABR and ASSR thresholds were evaluated to determine differences between the estimates from the two methods.

Results

Despite of sedation and anaesthesia, large wave V amplitudes of the chirp evoked 40-Hz ABR were found at levels as low as 10 dB above the individual ABR threshold. ASSR thresholds for stimulus repetition rates of 40 Hz could be consistently estimated in all 34 infants. Thresholds estimated from the ASSR for the four frequencies of the narrow-band chirps and the threshold derived from the broad-band chirp ABR differ, on average by 3.7 dB for the frequency range of 1000–2000 Hz and 7.1 dB for the frequency range from 2000 to 4000 Hz.

Conclusion

In contrast to the general assumption that 40-Hz ASSR are not appropriate for threshold estimation in infants our results demonstrate that multiple ASSR with a stimulus repetition rate of 40 Hz can be recorded in sedated and anaesthetized infants using narrow-band chirps. Threshold estimates obtained with 40-Hz ASSR are, on average, slightly higher than those obtained with chirp evoked ABR but allow for a frequency specific characterisation of the hearing ability.     

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.     

Evaluation of residual hearing in cochlear implants candidates using auditory steady-state response

Conclusion: The correlations between behavioral and auditory steady-state response (ASSR) thresholds were significant at 500, 1000, 2000, and 4000 Hz. ASSR presented high sensitivity and specificity in the detection of residual hearing in cochlear implant candidates when compared with warble-tone audiometry. Objectives: To assess residual hearing in cochlear implant candidates by comparing the electrophysiological thresholds obtained in dichotic single-frequency ASSR with behavioral thresholds at 500, 1000, 2000, and 4000 Hz. Methods: This was a comparative study between ASSR and warble-tone audiometry thresholds in 40 cochlear implant candidates (80 ears) before cochlear implantation with bilateral severe-to-profound sensorineural hearing loss. Results: Thresholds were obtained in 62.5% of all frequencies evaluated in warble-tone audiometry and in 63.1% in the ASSR. ASSR sensitivity was 96% and specificity was 91.6%. Mean differences between behavioral and ASSR thresholds did not reach significance at any frequencies. Strong correlations between behavioral and ASSR thresholds were observed in 500, 1000, and 2000 Hz and moderate in 4000 Hz, with correlation coefficients varying from 0.65 to 0.81. On 90% of occasions, ASSR thresholds were acquired within 10 dB of behavioral thresholds.     

同步多频听觉稳态诱发反应与听性脑干诱发电位相关性研究

目的探讨同步多频听觉稳态诱发反应(auditory steady-state responses to multiple simultaneous stimuli,MSS-ASSR)与听性脑干诱发电位(auditory brainstem response audiometry,ABR)的关系。方法受试者为不同程度听力损失的儿童70名(140耳),年龄范围为3月龄～6岁。测试状态为水合氯醛镇静睡眠。仪器采用美国INTELLEGENT HEARING的诱发电位仪,MSS-ASSR及ABR测试的软件分别为SMART ASSR和SMART EP,刺激声信号的载波频率为0．5kHz、1kHz、2kHz及4kHz。左耳上述各个载波频率的调制频率分别为77Hz、85Hz、93Hz、101Hz,右耳为79Hz、87Hz、95Hz、103Hz。测试时,双耳八个调幅调制声信号经ER-3A标准插入式耳机同时给出。ABR的刺激声为短声,极性为交替波,刺激速率为19．3次／分,耳机也是ER-3A插入式耳机。受试儿先进行ABR测试、然后进行MSS-ASSR的测试,分别以降10升5法得出二者的反应阈。将MSS-ASSR 0．5kHz、1kHz、2kHz和4kHz的反应阈与ABR反应阈比较,以SPSS 10．0软件进行相关性分析。结果除去58耳ABR无反应外,剩余82耳ABR反应阈与MSS-ASSR 0．5kHz、1kHz、2kHz、4kHz的反应阈相关性具有显著性意义(P=0．000)。Pearson相关系数分别为0．757,0．854,0．906,0．912。结论MSS-ASSR作为儿童听力定量诊断的客观方法有很大的临床应用价值。     

听性稳态反应在新生儿听力评估中的应用

目的 探讨听性稳态反应(auditory steady-state responses,ASSR)在新生儿听力评估中的准确性及应用价值.方法 对30例(60耳)畸变产物耳声发射(distortion product otoacoustic emission,DPOAE)正常的新生儿和45例(78耳)DPOAE异常的新生儿进行ASSR与听性脑干反应(auditory brainstem response audiome-try,ABR)测试,比较ASSR与ABR阈值差异有无统计学意义,并进行两者反应阈的相关性分析.结果 ①DPOAE正常组:ASSR 250 Hz反应阈与ABR阈值差异有统计学意义(P＜0.05),ASSR平均阈值及4 000 Hz反应阈与ABR阈值差异无统计学意义(P＞0.05),ASSR的250、500、1 000 Hz反应阈与ABR阈值相关性不明显,但2 000、4 000 Hz反应阈与ABR阈值有明显的相关性;②DPOAE异常组:ASSR的250～4 000 Hz阈值及平均阈值与ABR阈值差异均无统计学意义(P＞0.05).ASSR各频率反应阈与ABR阈值均有显著的相关性.结论 ASSR可以比较准确地评估听力筛查正常新生儿的平均听阈和中、高频听阈以及听力筛查未通过新生儿的各频率听阈.     

Hearing assessment by recording multiple auditory steady-state responses: the influence of test duration

The influence of test duration on the precision of hearing thresholds estimated by recording multiple auditory steady-state responses (ASSRs) was investigated. ASSR thresholds at four frequencies in both ears were assessed in 10 normal-hearing and 10 hearing-impaired subjects. The precision of the estimated hearing thresholds was compared for ASSR recordings of 5, 10 and 15 min per intensity level, corresponding to total test durations of approximately 30, 55 and 70 min for hearing-impaired ears. Furthermore, an intensity step size of 10 dB was compared to a step size of 5 dB. The mean difference scores averaged over the four frequencies were 15±10, 12±9 and 11±8 dB after recordings of 5, 10 and 15 min respectively. The corresponding Pearson correlation coefficients were 0.93, 0.95 and 0.96. Increasing the length of the separate recordings increases the precision of the estimates, independent of tested frequency. A compromise between both will have to be made. With a total test duration of approximately 1 h, four hearing thresholds in both ears can be estimated with a standard error of the estimate of 8dB.     

Comparison of multiple auditory steady-state responses (80 versus 40 Hz) and slow cortical potentials for threshold estimation in hearing-impaired adults

This study evaluated the use of multiple auditory steady-state responses (ASSRs) and slow cortical potentials (SCPs) to estimate behavioural audiograms in adults for compensation cases. Two groups of 23 subjects were assessed using either 80 Hz or 40 Hz multiple simultaneous tones with carrier frequencies of 0.5, 1.0, 2.0, and 4.0 kHz. SCP thresholds for 0.5, 1.0, and 2.0 kHz were obtained for both groups. Mean evoked potential thresholds (dB HL) minus behavioural pure-tone thresholds (dB HL) difference scores were 5–17 dB for the 80 Hz group, 1–14 dB for the 40 Hz group, and 20–22 dB for the SCPs. Thresholds for 40 Hz ASSR were significantly closer to behavioural thresholds than were 80 Hz or SCP thresholds. SCP and 40 Hz ASSR audiogram estimates were obtained more quickly than the 80 Hz ASSR. Multiple 40 Hz ASSR is the method of choice for evoked potential threshold estimation in adults.

Sumario

Este estudio evaluó el uso de las respuestas auditivas múltiples de estado estable (ASSR) y de los potenciales corticales lentos (SCP) para estimar en casos de compensación, los audiogramas comportamentales de adultos. Se realizaron pruebas en dos grupos de 23 sujetos utilizando tonos múltiples simultáneos a 80 ó 40 Hz con frecuencias portadoras de 500, 1000, 2000 y 4000 Hz. Se obtuvieron umbrales SCP para 500, 1000 y 2000 Hz en ambos grupos. Los umbrales promedio de potenciales evocados (dBHL) menos las respuestas tonales comportamentales se ubicaron entre 5 y 17dB para el grupo de 80 Hz, de 1 a 40 dB para el grupo de 40 Hz y de 20 a 22 dB para los SCP. Los umbrales de las ASSR de 40 Hz estuvieron significativamente mas cercanos a los umbrales comportamentales que los de 80 Hz o los umbrales SCP. Los SCP y las ASSR-40 Hz se obtuvieron más rápido que las ASSR-80 Hz. Las ASSR múltiples de 40 Hz son el método de elección para la estimación de umbrales con potenciales evocados en adultos.