摘要：
Objective To estimate tone-pip auditory brainstem response(tone-pip ABR) and auditory steady-state response(ASSR)thresholds to follow the development of hearing in four groups of normal babies through the first 6 month of life and to make a comparison between the tone-pip ABR and ASSR for 0.25-8 kHz frequency range at different groups. Methods The tone-pip ABR and ASSR were recorded in four groups of normal hearing infants(160 ears)at the age of 2-4 day,6 weeks,3-month and 6-month.Tone-pip ABR and ASSR thresholds were established in 0.25,0.5,1,2,4 and 8 kHz stimuli. Results For click ABR, the wave latency of Ⅰ,Ⅲ,Ⅴ and inter-wave latency of Ⅰ-Ⅲ,Ⅲ-Ⅴ and Ⅰ-Ⅴdecreased as the age increase. The developmental changes were obvious in wave Ⅰ and Ⅲ before 6 weeks and 3 months respectively. Tone-pip ABR had the similar waveform as the click ABR With the frequency increasing, their waveforms and wave latencies of Ⅰ,Ⅲ and Ⅴ were getting better and shorter respectively. There was significant difference between the thresholds of tone-pip ABR and ASSR(all P＜0.05 ).The tone-pip ABR thresholds were significantly lower than those of ASSR from 0.5 to 8 kHz. Both ASSR and tone-pip ABR had similar audiograms for different age of infants with normal heating. Conclusions The longitudinal findings presented in this study suggest that with the maturational development, the wave latency of Ⅰ,Ⅲ,Ⅴand inter-wave latency of Ⅰ-Ⅲ,Ⅲ-Ⅴ and Ⅰ-Ⅴ of tone-pip ABR decrease as the age increase, while the hearing sensitivity have no changes. Both tone-pip ABR and ASSR have stable frequency specificity. Compared to the ASSR, tone-pip ABR have lower response threshold and maybe nearer to the hearing level of the infant.%目的 建立听力正常婴儿短音听性脑干反应(tone-pip ABR)和听觉稳态反应(auditorysteady state response,ASSR)反应阈的正常参考值,研究其听觉发育的生物学规律,并比较两种听力检测技术的频率特性.方法 选取0～6月龄听力正常婴儿80例(160耳),按月龄分为四组:新生儿组、42 d组、3月龄组和6月龄组,每组20例(40耳),男女例数均等,分别记录其短声ABR的潜伏期及在0.25、0.5、1、2、4、8 kHz频率范围内tone-pip ABR和ASSR的反应阈.结果 在70 dB正常听力级短声刺激下,短声ABRⅠ、Ⅲ、Ⅴ波潜伏期、Ⅰ～Ⅲ、Ⅲ～Ⅴ、Ⅰ～Ⅴ波间期随月龄增加逐渐缩短,波Ⅰ于42 d前、波Ⅲ于3个月前发育变化显著.tone-pip ABR波形与短声ABR相似,Ⅰ、Ⅲ、Ⅴ波潜伏期随频率增加逐渐缩短,波形分化逐渐清晰.不同频率、不同月龄tone-pip ABR和ASSR反应阈差异具有统计学意义(P值均＜0.05).除0.25 kHz外,其余频率tone-pip ABR反应阈均低于ASSR.不同月龄tone-pip ABR和ASSR听力曲线形状相似.结论 0～6月正常婴儿tone-pip ABR的潜伏期和波间期随月龄增加逐渐缩短,而反应阈无明显变化.tone-pip ABR和ASSR均有稳定的频率特异性,tone-pip ABR反应阈低于ASSR,可能更接近主观纯音听阈.
