年龄对言语诱发 ABR 的频率跟随反应影响

目的：分析听力正常青年人与老年人之间言语诱发听性脑干反应（speech evoked auditory brainstem response ，s－ABR）的频率跟随反应（frequency following response ，FFR）差异，探讨其在揭示听觉系统老化机制中的作用。方法应用SmartEP听觉诱发电位系统对听力正常青年人（18～25岁）与老年人（60～70岁）各12例（24耳）进行言语声信号／da／诱发的s－ABR检测，比较两组s －ABR波形图及频谱图、FFR各波潜伏期及共振峰等。结果老年组s－ABR瞬态反应部分各波潜伏期较青年组延长，FFR各波潜伏期与青年组一致，FFR各波振幅较青年组低；两组FFR的频谱分析显示，老年组FFR各频率共振峰的相对能量较青年组低，且对于大多数共振峰，老年组FFR与刺激信号之间共振峰频率的差值较青年组大。结论与青年人相比，老年人FFR幅值低、准确性差，提示老化使脑干神经元对频率信息的编码能力减弱、准确性降低，这可能是造成老年性聋患者言语识别率降低的机制之一。

The Effects of Aging on Frequency Following Response in Speech Evoked Auditory Brainstem Response

Objective This study was to record the speech evoked auditory brainstem response (s-ABR) of normal hearing young and aged people ,then compared the frequency following responses (FFR) of s-ABR between the two groups ,in order to explore the contribution of FFR on revealing possible aging mechanisms of central audi‐tory system .Methods Twelve normal hearing young adults and aged people respectively (24 ears) were enrolled and s-ABRs (syllable/da/) were recorded using a SmartEP auditory evoked potential system .Results The comparison of waveforms between the two groups showed that the wave latencies of transient responses in the aged group was longer than that of young group ,while the wave latencies of the sustained response ,FFR ,were of no significant differences .The amplitudes of FFR waves in the aged group were lower than those of in the young group .The FFR spectrum analysis showed that the relative energy of each formant for the aged group was lower than that of in the young group and for some formants .Moreover ,for the aged group ,formant frequency differences between FFR and stimulus signal were greater than the young group .Conclusion Compared with young people ,the FFR of aged peo‐ple showed lower amplitudes and less accuracy ,meaning that aging can lead to the weakness of the brainstem neurons'spectral encoding ability .It may be one of the mechanisms causing the reduction of speech recognition in presbycusis patients .