短纯音及切迹噪声掩蔽的短纯音ABR对感音神经性听力损失成年人纯音听阈的评估

摘要

Objective Thresholds for auditory brain stem responses (ABRs) to tone burst and tone burst in notched noises of two different intensities were tested in adults with sensorineural hearing loss.The relationship between ABR and puretone thresholds was analyzed to identify an acoustic stimuli with better frequency-specificity.Methods Thirty-eight adults with sensorineural hearing loss (totally 45 ears) were included in the study.Tone burst used to elicit ABRs had 2.5 cycles on the rise and fall and no plateau.Notched noises of two different intensities were used to mask tone burst ipsilaterally when recording ABRs.Those two kinds of notched noises were 25 dB (intensity A) and 15 dB (intensity B) lower than tone burst in intensity respectively.Tone burst ABRs without masking were named tb-ABR,while tone burst ABRs in notched noises of intensity A and B named as amtb-ABR and bmtb-ABR.Thresholds for tb ABR,amtb ABR and bmtb-ABR were tested and analyzed.Results The regression coefficients between puretone thresholds and thresholds for tb-ABR,amtb-ABR and bmtb-ABR of all frequencies were greater than 0.8.The mean differences between ABR and puretone thresholds were all less than 10 dB.Tb-ABR thresholds the were the closest to puretone thresholds at 500 Hz,while bmtb ABR thresholds were the closest at the other three frequencies.Bmtb-ABR thresholds were more close to puretone thresholds in patients with steeply sloping hearing loss.Conclusion Thresholds for all those three ABRs could be used to predict puretone thresholds.In most condition,tb-ABR thresholds were able to estimate puretone thresholds.In some condition,different stimuli could be chosen to elicit ABR at different frequencies.It was reasonable to choose bmtb -ABR for puretone thresholds estimation in patients with steeply sloping hearing loss.%目的 比较感音神经性听力损失成年人短纯音及两种不同强度切迹噪声掩蔽短纯音诱发的听性脑干反应(auditory brain stem response,ABR)反应阈与纯音听阈的关系,以选取频率特异性更好的ABR声刺激信号.方法 对38例(45耳)经纯音听阈测试诊断为感音神经性听力损失的成年人分别进行短纯音(上升/下降时间各2.5个周期,无平台)ABR(tb-ABR)测试及以较短纯音强度低25 dB(A强度)和15 dB(B强度)切迹噪声对短纯音进行同侧掩蔽的ABR(分别简称amtb-ABR和bmtb-ABR)测试,分析三种ABR反应阈与纯音听阈的关系.结果 各频率tb-ABR、amtb-ABR和bmtb-ABR反应阈与纯音听阈的相关系数均大于0.8;500、1 000、2 000、4 000 Hz四个频率三种ABR反应阈与纯音听阈之差的均值均小于10 dB,其中,500 Hz tb-ABR反应阈最接近纯音听阈,其它3个频率bmtb-ABR反应阈最接近纯音听阈;在陡降型听力损失患者中,bmtb-ABR反应阈与纯音听阈更接近.结论 tb-ABR、amtb-ABR及bmtb-ABR反应阈均可用于估计纯音听阈,一般情况下,可用tb-ABR反应阈预估纯音听阈;特定情况下,不同测试频率可选用不同的声信号;而对于陡降型听力损失患者,bmtb-ABR反应阈预估纯音听阈更为准确.