短音骨导听性稳态反应中伪迹的研究

Artifactual Responses when Recording Auditory Steady-State Responses to Bone-Conduction Stimuli

目的研究短音骨导听性稳态反应中的伪迹问题。方法对21例(21耳)双耳极重度感音神经性聋患儿行骨导ASSR检测,刺激信号为0.5～4kHz倍频程的短音(tonepip),0.5kHz刺激信号上升、下降时间均为4ms;1、2、4kHz为2ms,0.5、1、2、4kHz刺激信号的刺激速率分别为77、85、93、101Hz。通过B-71骨振器给声,记录ASSR波形并观察是否出现伪迹,分析其原因。结果 1、4kHz出现伪迹的强度分别为115和100.5dB,0.5和2kHz分别在120.5和112dB(re:1μN)(以上强度约相当于听力级的60dBHL)未出现伪迹。结论骨导AS-SR的最大输出较气导小,且易出现伪迹,故骨导听力损失超过中度以上者,不宜行短音骨导听性稳态反应测试。

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：1μN） （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.