正常听力成人骨导听性稳态反应的研究

Bone-conducted Auditory Steady-state Responses in Adults with Normal Hearing

目的①通过正常听力成人乳突和耳后听性稳态反应(auditory steady-state response,ASSR)测试信号行为阈值的测试,研究骨振器位置与反应阈的关系并建立该信号骨导的正常听力级;②通过单频及多频刺激方式骨导ASSR的反应幅值及阈值的比较,研究刺激方式对骨导ASSR的影响。方法ASSR测试信号为0.5、1、2、4kHz短音(0.5kHz的上升/下降时间为4ms,1、2和4kHz为2ms,无平台),其重复速率分别为77、87、93、101Hz,经B-71骨振器给出。将正常听力成人分为两组,实验1组(30人),分别记录0.5、1、2、4kHzASSR测试信号在乳突、耳后的骨导行为阈值;实验2组(12人),分别采用单、多频刺激方式,记录其0.5、1、2、4kHz的反应阈以及刺激强度为50dBnHL时的反应幅值。结果①骨振器位于乳突与耳后的骨导行为阈值无显著性差异,0.5、1、2、4kHz的骨导行为反应阈分别为62.6±4.8、47.1±4.8、46.8±6.2、32.4±5.1dBre:1μN(ppe),取该反应阈的均值作为本研究所使用信号的骨导正常听力级,记作0dBnHL;②在刺激强度为50dBnHL时,不同刺激方式间反应幅值差异有显著统计学意义;③单、多频刺激方式间骨导ASSR阈值差异无统计学意义,0.5、1、2、4kHz阈值分别为96.7±9.7、70.3±11.6、60.6±7.4、52.8±7.2dBre:1μN(ppe),各频率间差异有显著统计学意义。结论①骨振器位于乳突与耳后对行为阈值没有显著性影响;②在刺激强度为50dBnHL时,单、多频刺激方式的反应幅值差异有显著统计学意义;③单、多频刺激方式下,骨导ASSR阈值差异无统计学意义。

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 --stimulus conditions. ①Behavioral bone--conducted thresholds to ASSR stimuli with mastoid and behind--the-- ear placement were measured at 0.5, 1, 2 and 4 kHz; ②The amplitudes and thresholds under single-- and multiple -- stimulus condition were measured at the above octave frequencies. Results ①The analysis of thresholds indica 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±4.8,46.8±6.2,32.4±5. 1 dB re： 1μN （ppe）, respectively. ②Setting 50 dB nHL as the normalized base level, significant differences were noted in amplitudes between single-- and multiple--stimulus conditions. ③There was no signifi- cant 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.