Characteristics of auditory steady-state response in first-degree relatives of schizophrenic patients under eye-open/closed state / 中华行为医学与脑科学杂志

Objective:To study the effect of eye-open/closed state on 40 Hz auditory steady state response (ASSR) in first-degree relatives of schizophrenia.Methods:Thirty-eight first-degree relatives of schizophrenic patients treated in Shanghai Mental Health Center from March 2010 to October 2011 were selected, and 31 healthy controls were recruited in the same period. All subjects were assessed with schizotypal personality questionnaire (SPQ). The 40 Hz EEG ASSR signals lasting for 3 min under open and closed eyes of all subjects were sequentially collected.Event-related spectrum perturbation (ERSP) and intertribal phase coherence (ITC) were used to evaluate ASSR. SPSS 22.0 software was used for statistical analysis. Two-way analysis of variance was used to compare ITC and ERSP between the two groups under open and closed eyes. Spearman correlation analysis was used to analyze the correlation between each measurement.Results:ITC in group main effect and group×the eye open/closed interaction effect were not significant (both P>0.05), but the main effect of eye-open and eye-closed was significant ( F(1, 67)=10.61, P=0.002). In the healthy control group, the ITC in eye-open state was significantly higher than that in eye-closed state ( P=0.014), and in the first-degree relatives group, the ITC in eye-open state was higher than that in eyes closed state ( P=0.039). ERSP in the main effect of eye-open and eye-closed ( F(1, 67)=0.195, P=0.660), group main effect ( F(1, 67) =0.627, P=0.431), group × the eye-open/closed interaction effect ( F(1, 67)= 1.034, P=0.313) was not significant. Spearman correlation analysis showed that there was no correlation between ERSP (eye open: r=-0.260, P=0.210; eye closed: r=-0.318, P=0.122), ITC (eye open: r=-0.248, P=0.232; eye closed: r=-0.260, P=0.209) and SPQ score in the healthy control group. There was also no correlation between ERSP (eye open: r=-0.387, P=0.226; eye closed: r=-0.363, P=0.238) or ITC (eye open: r=0.126, P=0.485; eye closed: r=0.096, P=0.595) and SPQ score in the first-degree relatives group of schizophrenia. Conclusion:The regulation pattern of 40 Hz ASSR in schizophrenic first-degree relatives is not significantly impaired in the eye-open/closed state, suggesting that the open/closed regulation pattern of 40 Hz ASSR may not be a potential marker for predicting the genetic high-risk prognosis of schizophrenia.

Comparison of ASSR, ABR and 40 Hz AERP Response Thresholds at Different Frequencies and Their Forensic Applications / 法医学杂志

OBJECTIVES@#To explore the relationship between the frequency characteristics and response threshold of auditory steady-state response (ASSR), auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP), and their application values in forensic medicine.@*METHODS@#Thirty volunteers with normal hearing (60 ears) were selected to perform pure tone audiometry (PTA) threshold and ASSR, ABR and 40 Hz AERP response threshold tests in the standard sound insulation shielding room, and the results were statistically analyzed by SPSS 22.0 software.@*RESULTS@#At 0.5 kHz and 1.0 kHz frequencies, the correlation between 40 Hz AERP response threshold and PTA threshold was good, which was better than that of ASSR and ABR response threshold. At 2.0 kHz and 4.0 kHz frequencies, the correlation between ASSR and ABR response thresholds and PTA threshold was good, which was better than that of 40 Hz AERP response threshold.@*CONCLUSIONS@#To evaluate the hearing at 0.5 kHz and 1.0 kHz frequencies, it is recommended to use 40 Hz AERP and ASSR to comprehensively assess the PTA threshold of the subjects. To evaluate the hearing at 2.0 kHz and 4.0 kHz frequencies, ABR and ASSR are recommended to assess the PTA threshold of subjects comprehensively. The combination of ASSR, ABR and 40 Hz AERP can improve the accuracy of hearing function evaluation.

Evaluation of the newborn hearing screening program in The Medical City based on Joint Commission on Infant Hearing (JCIH) 2007 position statement quality indicators

Objective@#The objective of this study is to evaluate the newborn hearing screening program in The Medical City based on the Joint Committee on Infant Hearing (JCIH) 2007 Position Statement Quality Indicators. @*Methods@#Study Design: Cross - Sectional Survey. Setting: Tertiary Private Hospital. Participants: All newborns who underwent newborn hearing screening in The Medical City for the year 2015. @*Results@#Of 2,010 patients delivered in the hospital in year 2015, 1,986 (98.8%) were screened. Among the 59 babies with initial “refer” results, 15 (25.42%) “referred” a second time while 24 (40.68%) “passed” the rescreening. Twenty (33.89%) did not undergo rescreening (10 were classified as dropouts, while another 10 did not undergo rescreening for various reasons. Of those who “referred” during rescreening, only 9 (60%) had further evaluation done with ABR/ASSR. Among these, 4 (26.66%) had hearing loss and proceeded with the appropriate monitoring and management while 5 (33.33%) had normal hearing. @*Conclusion@#The current newborn hearing screening program in the Medical City was able to reach JCIH 2007 quality indicators for screening but not for confirmation of hearing Loss. All patients with hearing loss were managed with early rehabilitation.

Mode of recording and modulation frequency effects of auditory steady state response thresholds / Modo de registro e efeitos da modulação em frequências nos limiares de resposta auditiva de estado estável

Abstract Introduction The performance of auditory steady state response (ASSR) in threshold testing when recorded ipsilaterally and contralaterally, as well as at low and high modulation frequencies (MFs), has not been systematically studied. Objective To verify the influences of mode of recording (ipsilateral vs. contralateral) and modulation frequency (40 Hz vs. 90 Hz) on ASSR thresholds. Methods Fifteen female and 14 male subjects (aged 18–30 years) with normal hearing bilaterally were studied. Narrow-band CE-chirp® stimuli (centerd at 500, 1000, 2000, and 4000 Hz) modulated at 40 and 90 Hz MFs were presented to the participants' right ear. The ASSR thresholds were then recorded at each test frequency in both ipsilateral and contralateral channels. Results Due to pronounced interaction effects between mode of recording and MF (p < 0.05 by two-way repeated measures ANOVA), mean ASSR thresholds were then compared among four conditions (ipsi-40 Hz, ipsi-90 Hz, contra-40 Hz, and contra-90 Hz) using one-way repeated measures ANOVA. At the 500 and 1000 Hz test frequencies, contra-40 Hz condition produced the lowest mean ASSR thresholds. In contrast, at high frequencies (2000 and 4000 Hz), ipsi-90 Hz condition revealed the lowest mean ASSR thresholds. At most test frequencies, contra-90 Hz produced the highest mean ASSR thresholds. Conclusions Based on the findings, the present study recommends two different protocols for an optimum threshold testing with ASSR, at least when testing young adults. This includes the use of contra-40 Hz recording mode due to its promising performance in hearing threshold estimation.

Resumo Introdução O desempenho da resposta auditiva de estado estável (RAEE) em testes de limiar com registros ipsilateral e contralateral e modulações em frequências (MFs) não tem sido sistematicamente estudado. Objetivo Verificar a influência do modo de registro (ipsilateral vs. contralateral) e da modulação em frequências (40 Hz vs. 90 Hz) nos limiares de RAEE. Método Foram estudados 15 mulheres e 14 homens (18-30 anos) com audição bilateral normal. Estímulos CE-chirp® de banda estreita (centrados em 500, 1.000, 2.000 e 4.000 Hz) modulados em 40 e 90 Hz de MF foram apresentados à orelha direita dos participantes. Em seguida, os limiares de RAEE foram registrados em cada frequência de teste nos canais ipsilateral e contralateral. Resultados Devido aos pronunciados efeitos de interação entre o modo de registro e MF (p < 0,05 por variância com dois fatores para medidas repetidas – Anova duas vias), os limiares médios de RAEE foram então comparados entre quatro condições (Ipsi-40 Hz, Ipsi-90 Hz, Contra-40 Hz e Contra-90 Hz), com o uso de variância e com um fator para medidas repetidas (Anova uma via). Nas frequências de teste de 500 e 1.000 Hz, a condição Contra-40 Hz produziu os mais baixos limiares médios de RAEE. Em contraste, em altas frequências (2.000 e 4.000 Hz), a condição Ipsi-90 Hz revelou os mais baixos limiares médios de RAEE. Na maioria das frequências de teste, a condição Contra-90 Hz produziu os mais elevados limiares médios de RAEE. Conclusões Com base nos achados do presente estudo, os autores recomendam dois protocolos diferentes para um teste de limiares ideal com RAEE, pelo menos em adultos jovens. Isso inclui o uso do modo de registro Contra-40 Hz, devido ao seu desempenho promissor nas estimativas do limiar auditivo.

Crosscheck Principle in Pediatric Audiology Today: A 40-Year Perspective

The crosscheck principle is just as important in pediatric audiology as it was when first described 40 years ago. That is, no auditory test result should be accepted and used in the diagnosis of hearing loss until it is confirmed or crosschecked by one or more independent measures. Exclusive reliance on only one or two tests, even objective auditory measures, may result in a auditory diagnosis that is not clear or perhaps incorrect. On the other hand, close and careful analysis of findings for a test battery consisting of objective procedures and behavioral tests whenever feasible usually leads to prompt and accurate diagnosis of auditory dysfunction. This paper provides a concise review of the crosscheck principle from its introduction to its clinical application today. The review concludes with a description of a modern test battery for pediatric hearing assessment that supplements traditional behavioral tests with a variety of independent objective procedures including aural immittance measures, otoacoustic emissions, and auditory evoked responses.

Comparision results between ABR and ASSR thresholds in children / Шинэ санаа Шинэ нээлт

Over 5% of the world’s population – 360 million people – has disabling hearing loss (328 million adults and 32 million children). Early diagnosis of hearing loss in children and providing hearing devices, including cochlear implants helps to develop speech, language, and listening skills needed for oral communication. Because of this reason, identifying children early with accurate hearing assessment in children is crucial. The aim of this study was to determine advantage of auditory steady-state response testing in comparing ABR and ASSR thresholds in children with severe hearing loss.Totally 21 children, 8 female and 13 males, aged between 18 and 46 months were included to this study.Mean age was 26 months. All the children underwent otoscopy and ABR before the measurement ofASSR thresholds. ABR and ASSR threshold measurements were performed by different physicians.They were performed in a quiet room, where sound level is less than 50 dB. Each child was asleep by nature during the test. Pearson’s correlation test have been used to evaluate correlation of thehearing thresholds of ABR and ASSR.The hearing thresholds in ABR correlated well with the threshold obtained with ASSR (Pearson’scorrelation coefficient (0.231) is significant at the 0.01 level). In addition; in patients, where the thresholds for ABR were not measurable, it could be found in ASSR tests. If there is not any residual hearing for subjects, both tests resulted with no response.Based on these findings, both ABR and ASSR techniques may be used to provide an estimate of hearing sensitivity in children, but ASSR is a more valuable test than ABR. Determining thresholds for 0.5, 1, 2, 4 kHz is very important. Identifying children early with accurate hearing assessment leads to earlier fitting of sensory devices, including cochlear implants, which minimizes delays in auditory, speech, and language development.

Usefulness of Objective Hearing Tests for Screening Patients with Partial Deafness / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: 'Partial deafness' characterized by normal or slightly impaired hearing in the low frequency band and nearly total deafness in the high frequency range, is difficult to assess with conventional behavioral tests in infants and young children. Therefore, this study aimed to assess the usefulness of objective hearing tests, such as auditory brainstem response (ABR) and auditory steady state response (ASSR) in evaluating patients with partial deafness. SUBJECTS AND METHOD: One hundred thirty three patients who underwent ASSR in Ajou University Hospital from January 2008 to January 2013 were enrolled to this study. Correlations between ASSR, ABR and pure tone audiometry (PTA) thresholds were analyzed. RESULTS: ASSR thresholds of 133 patients were highly correlated with both ABR and PTA thresholds in majority of the tested frequencies. Partial deafness was detected in 9 out of 133 patients, based on the results of PTA and ASSR. ASSR thresholds of patients with partial deafness were significantly correlated with PTA thresholds in all frequencies, with especially high correlation found at 1 and 4 kHz. However, there was no significant correlation between ASSR and ABR thresholds. ABR thresholds of partial deafness patients were measured at 65 dB in one patient, 70-90 dB in 3 patients, and no response at 90 dB in 5 patients, respectively. In 8 (6%) out of 124 patients, ABR thresholds were measurable with profound hearing loss and residual hearing was observed at low frequencies. CONCLUSION: ASSR is useful for predicting residual hearing at low frequencies of infants and young children for whom assessment of hearing is difficult using conventional behavioral tests.

Comparision results between ABR and ASSR thresholds in children / Шинэ санаа Шинэ нээлт

Over 5% of the world’s population – 360 million people – has disabling hearing loss (328 million adults and 32 million children). Early diagnosis of hearing loss in children and providing hearing devices, including cochlear implants helps to develop speech, language, and listening skills needed for oral communication. Because of this reason, identifying children early with accurate hearing assessment in children is crucial. The aim of this study was to determine advantage of auditory steady-state response testing in comparing ABR and ASSR thresholds in children with severe hearing loss. Totally 21 children, 8 female and 13 males, aged between 18 and 46 months were included to this study. Mean age was 26 months. All the children underwent otoscopy and ABR before the measurement of ASSR thresholds. ABR and ASSR threshold measurements were performed by different physicians. They were performed in a quiet room, where sound level is less than 50 dB. Each child was asleep by nature during the test. Pearson’s correlation test have been used to evaluate correlation of thehearing thresholds of ABR and ASSR. The hearing thresholds in ABR correlated well with the threshold obtained with ASSR (Pearson’s correlation coefficient (0.231) is significant at the 0.01 level). In addition; in patients, where the thresholds for ABR were not measurable, it could be found in ASSR tests. If there is not any residual hearing for subjects, both tests resulted with no response. Based on these findings, both ABR and ASSR techniques may be used to provide an estimate of hearing sensitivity in children, but ASSR is a more valuable test than ABR. Determining thresholds for 0.5, 1, 2, 4 kHz is very important. Identifying children early with accurate hearing assessment leads to earlier fitting of sensory devices, including cochlear implants, which minimizes delays in auditory, speech, and language development.

The Diagnostic Value of Auditory Steady State Response in Patients of Idiopathic Sudden Sensorineural Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Sudden sensorineural hearing loss (SSNHL) is a medical emergency when an individual experiences at least 30 dB (decibels) of sudden SSNHL, occurring over a time period of three days or less. Pure tone audiometry (PTA) is by far the most widely used to diagnose SSNHL. Besides PTA, auditory steady-state response (ASSR) is also generally accepted to predict the hearing of SSNHL patients objectively and effectively. We analyzed correlation between ASSR and PTA in SSNHL patients, compared that with the corresponding data in non-SSNHL patients, and studied the usefulness of correlation between ASSR and PTA to forecast prognosis of SSNHL in clinical applications. SUBJECTS AND METHOD: We retrospectively analyzed the charts of SSNHL patients. We analyzed the correlation between the thresholds of PTA, ASSR, and audiotory brainstem response (ABR) in SSNHL, compared that with corresponding data in non-SSNHL patients. RESULTS: There was a very strong positive linear correlation between the average hearing threshold of ASSR and PTA among the non-SSNHL patients. Furthermore, there was relatively strong positive linear correlation between the average hearing threshold of ASSR and PTA among SSNHL patients. Also there was a normal positive linear correlation between the average hearing threshold of ABR and PTA among SSNHL patients. The average hearing threshold difference between ASSR and PTA among SSNHL patients was smaller compared with non-SSNHL patients, and this was statistically significant. CONCLUSION: There was a strong correlation between the average hearing threshold of ASSR and PTA among non-SSNHL & SSNHL patients. Compared to ABR, ASSR showed greater correlation with PTA in the SSNHL patients. We concluded that ASSR could be a useful diagnostic tool in SSNHL.

Hearing Threshold Prediction Using Auditory Brainstem Response and Auditory Steady-State Response in Infants and Young Children / 대한이비인후과학회지

Between one and three of every 1,000 neonates have sensorineural hearing loss (SNHL). It is of utmost importance to minimize the duration of auditory deprivation between the onset of bilateral deafness and intervention using hearing devices such as hearing aids and cochlear implants for achieving the best speech percpetion ability. To fit amplification accurately for children with SNHL, hearing thresholds for frequencies in the range of human communication should be evaluated. However, infants and young children are difficult to test using conventional behavioral tests, and hearing thresholds of them can be predicted using auditory brainstem response (ABR) and auditory steady-state response (ASSR). ABR is best evoked by applying a click stimulus, which allows an estimate over a broad range of high frequencies. ABR elicited by tone burst stimulus provides frequency-specific audiometric information. However, it can be difficult to record and observe at near-threshold levels, especially at lower frequencies. ABR thresholds for click and tone burst stimuli are highly correlated with behavioral thresholds, and often give an idea of the shape of an audiogram. ASSR is an auditory evoked potential, elicited with modulated tones. It provides frequency-specific hearing thresholds across the audiometric frequencies, which are well correlated with behavioral thresholds. However, the accuracy of threshold prediction decreases directly with the decrease of degree of hearing loss, and hearing thresholds cannot be predicted for auditory neuropathy. ASSR is most useful for estimating auditory thresholds for patients with no evidence of auditory neuropathy by the click ABR and OAEs, and who have an ABR only at high intensities or no ABR at a maximum stimulus level. Even if hearing thresholds are predicted through ABR and ASSR, behavioral testing including behavioral observation audiometry, visual reinforcement audiometry, or play audiometry should be employed repeatedly to verify the predicted thresholds, becasue the thresholds of ABR and ASSR are not true measure of hearing acuity but just responses generated at the brainstem.

Repeatability of Auditory Steady State Response in Elderly with Sensorineural Hearing Impairment / Jurnal Sains Kesihatan Malaysia

Previous studies have found that Auditory Steady State Response (ASSR) has large variability in predicting hearing thresholds. However, not many studies have reported on its repeatability. This study aimed to determine the repeatability of ASSR in evaluating hearing thresholds in elderly with sensorineural hearing impairment. A total of 15 subjects aged 55 to 75 years old were involved in this study. Hearing thresholds were determined using pure tone audiometry (PTA) and ASSR at frequencies 0.5, 1, 2 and 4 kHz. ASSR were repeated at frequencies 0.5 and 1 kHz. Overall, hearing thresholds obtained with ASSR were higher than PTA. One-way ANOVA showed the difference between thresholds of PTA and ASSR were not significant at all frequencies. There is significant correlation between the PTA and ASSR thresholds at 0.5 kHz (r = 0.77, p 0.05) and 1 kHz (t = 0.436, p > 0.05). Pearson corelation showed moderate corelation between the two ASSR measurements at 0.5 kHz (r = 0.68, p < 0.001) and 1 kHz (r = 0.60, p < 0.001). The outcome of this study suggests that ASSR hearing threshold is not significantly different if test is repeated and ASSR can be recommended as an alternative to PTA in determining hearing threshold in elderly with sensorineural hearing impairment.

Aplicabilidade da resposta auditiva de estado estável em campo livre na avaliação de bebês e crianças usuárias de próteses auditivas / Applicability of the free-field steady-state auditory response in the assessment of infants and children using hearing aids

Introdução: A resposta auditiva de estado estável (RAEE) pode ser captada utilizando vários tipos de transdutores como fones supra-aurais, fones de inserção, vibrador ósseo e alto falante. A avaliação por meio de alto falante pode ser utilizada na determinação dos níveis mínimos de resposta em campo livre com e sem próteses auditivas. Objetivo: avaliar a aplicabilidade da RAEE em campo livre segundo a saída máxima do transdutor e tempo de exame. Métodos: Foram avaliadas 27 crianças com perda auditiva neurossensorial bilateral de grau moderado a profundo com faixa etária entre oito meses e 12 anos por meio da audiometria tonal e RAEE em campo livre, com e sem as próteses auditivas. Resultados: Na condição sem prótese auditiva, a presença de respostas na audiometria foi maior que na RAEE. Na condição com prótese auditiva, a presença de respostas na audiometria e na RAEE foi igual para as freqüências de 1000, 2000 e 4000 Hz. Não foi observada associação entre o tempo de exame e idade. O menor tempo médio de exame foi observado na perda auditiva de grau profundo, na condição sem prótese auditiva. Conclusões: Na condição com prótese auditiva, a presença de resposta tende a 100 % em ambos os procedimentos de avaliação nas diferentes freqüências. Não há associação entre o tempo de exame e variável idade. O tempo de exame nas crianças com perda auditiva de grau moderado e severo é maior do que no grau profundo, na condição sem prótese auditiva. Na condição com prótese auditiva, não há associação entre tempo de exame e o grau da perda auditiva.

Introduction : The auditory steady-state response (ASSR) can be recorded by the utilization of many kinds of transductors as supra-auricular phones, insertion phones, bone vibrator and loudspeaker. The assessment by loudspeaker may be used on the determination of minimal answer levels in free field with or without hearing aids. Objective : to evaluate the applicability of ASSR in free field according to maximum output of the transductor and the duration of the exam. Methods: 27 children aged from 8 months to 12 years, with bilateral neurossensorial hearing impairment from moderate to profound were evaluated by means of tonal audiometry and ASSR on soundfield with and without hearing aids. Results: In the condition without hearing aids, the answers presence in audiometry and ASSR was the same for frequencies of 1000, 2000 and 4000 Hz. No association was observed between the duration of the exam and age. The smallest time of duration of exam was observed with hearing impairment of profound degree, in the condition without hearing aid. Conclusions: In the condition with hearing aids, the answer presence tends towards 100% on both evaluation procedures on different frequencies. There is no association between duration of ASSR exam and age. The duration of the ASSR exam on children with moderate and severe hearing impairment is higher than with profound degree in condition without hearing aids. In the condition with hearing aids there is no association between duration of ASSR exam and hearing impairment degree.

Introduccion: La respuesta auditiva de estado estable (RAEE) se puede captar utilizando vários tipos de transdutores como auriculares supra-aurales, auriculares de inserción, vibrador oseo y altavoz. La evaluació por médio de altavoz puede ser usada para la derterminacíon de niveles mínimos de respuesta en campo libre con y sin audífonos. Objetivo: evaluar la aplicabildad de RAEE en campo libre de acuerdo con la salida máxima del transdutor y el tiempo de examen. Métodos: Se han evaluado 27 niños con perdida auditiva neurosensorial bilateral de grado moderado a profundo con edades entre ocho meses y 12 años por médio de la audiometria tonal y RAEE en compo libre con y sin audifonos. Resultados: En la condición sin uso de audifonos la presencia de respuesta en la audiometria fue maior que en la RAEE. En la condición con audifonos la presencia de respuestas en la audiomentria y en la RAEE fue igual para las frecuencias de 1000, 2000 y 4000 Hz. No se observó associación entre el tiempo de examen y la edad. El tiempo médio mas corto de examen fué observado para perdida de grado profundo, en la condición sin uso de audifono. Conclusión: En la condición con audifono la presencia de respuestas tiende a 100% en ambos procediemientos de evaluación en las diferentes frecuencias. No hay asociación entre tiempo de examen y la variable edad. El tiempo médio de examen para niños con perdida auditiva moderada y severa es maior que para niños con perdida profunda en la condición sin audifono. En la condición con audifono no hay asociación entre tiempo de examen y grado de perdida auditiva.

Bone-conducted Auditory Steady-state Responses in Adults with Normal Hearing / 听力学及言语疾病杂志

Objective This paper is to explore the relationship between the placement of the bone oscillator and bone-conducted thresholds to ASSR stimuli in adults with normal hearing and to investigate the amplitude and the threshold differences to bone-conducted auditory steady-state responses (BC-ASSR) stimuli between single - and multiple-stimulus conditions. Methods Two groups of subjects were selected with 0. 5, 1, 2 and 4 kHz brief tones repeated at the rate of 77, 87, 93 and 101 Hz using a B-71 bone oscillator either in single- or multiple ted no significant differences between mastoid and behind-the-ear placements. The mean and standard deviations of bone-conducted behavioral thresholds to ASSR stimuli at 0.5, 1, 2 and 4 kHz were 62.6±4.8,47.1±4.8,46.8cant difference between the two conditions while the mean and standard deviations of BC-ASSR thresholds at 0.5, 1, 2 and 4 kHz were 96.7±9.7,70.3±11.6,60.6±7.4,52.8±7.2 dB re: 1μN (ppe), respectively. Conclusion The behavioral bone-conducted thresholds to ASSR stimuli with mastoid and behind-the-ear placemen yielded no significant differences. When the stimuli intensity was 50 dB nHL, the amplitudes in single-stimulus condition were significantly higher than those to multiple-stimulus condition. There were no significant differences for BC-ASSR thresholds between single- and multiple-stimulus condition.

Clinical Comparison of the Auditory Steady-State Response with the Click Auditory Brainstem Response in Infants

OBJECTIVES: Our goal was to determine the effectiveness of using the auditory steady state response (ASSR) as a measure of hearing thresholds in infants who are suspected of having significant hearing loss, as compared with using the click-auditory brainstem response (C-ABR). METHODS: We retrospectively analyzed the audiologic profiles of 76 infants (46 boys and 30 girls, a total of 151 ears) who ranged in age from 1 to 12 months (average age: 5.7 months). The auditory evaluations in 76 infants who were suspected of having hearing loss were done via the C-ABR and ASSR. In addition, for reference, the mean ASSR thresholds were compared to those of 39 ears of infants and 39 ears of adults with normal hearing at 0.5, 1, 2, and 4 kHz. RESULTS: The highest correlation between the C-ABR and ASSR thresholds was observed at an average of 2-4 kHz (r=0.94). On comparison between the hearing of infants and adults at 0.5, 1, 2, and 4 kHz, the mean ASSR threshold in infants was 12, 7, 8, and 7 dB higher, respectively, than that in adults. CONCLUSION: ASSR testing may provide additional audiometric information for accurately predicting the hearing sensitivity, and this is essential for the management of infants with severe to profound hearing loss.

Comparison of Auditory Brainstem Response and Auditory Steady-State Response Thresholds in Infants and Young Children / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The aim of this study was to assess the accuracy of threshold estimates determined by the auditory steady-state response (ASSR) in a group of sedated infants and young children with a range of hearing losses. MATERIALS AND METHOD: Two studies were performed because the behavioral audiometric information was not available from infants and young children. In the first study, a retrospective analysis was performed for 36 children (mean age: 3 years 4 months) who had completed auditory brainstem response (ABR) and pure tone audiometry to verify that ABR threshold is a good predictor for pure tone threshold in our laboratory. The ABR thresholds to 500 Hz, 1000 Hz tone-pip and click were compared with behavioral thresholds. In the second study, a prospective analysis of 23 children (mean age: 12 months), the ABR thresholds to 500 Hz, 1000 Hz tone-pip and click were compared with ASSR thresholds to amplitude and frequency modulated tones. RESULTS: The first study in which strong correlations were found between ABR and pure tone thresholds (r> or =0.92) demonstrated that ABR thresholds could be used to predict the pure tone thresholds. The second study which showed that ASSR thresholds were highly correlated with ABR thresholds (r> or =0.93) indicated that ASSR thresholds provided reliable audiometric information in infants and young children. CONCLUSION: These studies showed that ASSR could be used to estimate hearing thresholds with reliable accuracy in infants and young children.

Artifactual Responses when Recording Auditory Steady-State Responses to Bone-Conduction Stimuli / 听力学及言语疾病杂志

Objective To explore artifactual responses of auditory steady-state reponses (ASSRs) to bone-conduction stimuli.Methods The present study involved a group of subjects,aged between 5 to 39 months,with bilateral profound sensorineural hearing losse.Recorded were the reponses to multiple bone-conducted 0.5,1,2,4 kHz tone pips repeated at the rates of 77～101 Hz.All the subjects were sedated by Hydrate Chloride during the testing.Results Artifactual ASSRs were seen at 115 and 100.5 dB (re:1?N) (The above levels are equivalent to around 60 dB HL) at 1 and 4 kHz.No artifactual responses were recorded at 0.5 and 2 kHz stimuli at the maximum output level.Conclusion Bone-conducted hearing loss greater than moderate can not be tested reliablely due to artifactual responses and lower maximum output level than that of air conduction.

Auditory Steady-state Response to Single or Simultaneously Multiple Bone-conduction Stimuli in Adults with Normal Hearing / 听力学及言语疾病杂志

Objective To get the thresholds of single and simultaneously multiple bone conduction auditory steady-state response(BC-ASSR) of young adults with normal hearing,and to compare the thresholds obtained with the two methods.Methods BC-ASSR to single and simultaneously multiple stimuli and PTA were examined in 28(56 ears ) young adults with normal hearing.Results At 0.5,1,2,4 kHz,the thresholds of BC-ASSR to single stimuli were 53,47,53,51 dB SPL respectively;the thresholds of BC-ASSR to simultaneously multiple stimuli were 59,54,63,61 dB SPL respectively.There were significant differences between the two at each frequency. Conclusion There are some difference between the thresholds of ASSR to single and simultaneously multiple bone conduction stimuli,especially at the higher frequencies.