Picton Terence W, Dimitrijevic Andrew, Perez-Abalo Maria-Cecilia, Van Roon Patricia
Rotman Research Institute, Baycrest Centre for Geriatric Care, University of Toronto, Canada.
J Am Acad Audiol. 2005 Mar;16(3):140-56. doi: 10.3766/jaaa.16.3.3.
Human auditory steady-state responses (ASSRs) were recorded using stimulus rates of 78-95 Hz in normal young subjects, in elderly subjects with relatively normal hearing, and in elderly subjects with sensorineural hearing impairment. Amplitude-intensity functions calculated relative to actual sensory thresholds (sensation level or SL) showed that amplitudes increased as stimulus intensity increased. In the hearing-impaired subjects this increase was more rapid at intensities just above threshold ("electrophysiological recruitment") than at higher intensities where the increase was similar to that seen in normal subjects. The thresholds in dB SL for recognizing an ASSR and the intersubject variability of these thresholds decreased with increasing recording time and were lower in the hearing impaired compared to the normal subjects. After 9.8 minutes of recording, the average ASSR thresholds (and standard deviations) were 12.6 +/- 8.7 in the normal subjects, 12.4 +/- 11.9 dB in the normal elderly, and 3.6 +/- 13.5 dB SL in the hearing-impaired subjects.
在正常年轻受试者、听力相对正常的老年受试者以及患有感音神经性听力障碍的老年受试者中，使用78 - 95Hz的刺激速率记录人类听觉稳态反应（ASSR）。相对于实际感觉阈值（感觉级或SL）计算的振幅-强度函数表明，振幅随刺激强度增加而增大。在听力受损的受试者中，在刚好高于阈值的强度下（“电生理重振”），这种增加比在较高强度下更快，在较高强度下，其增加与正常受试者相似。识别ASSR的dB SL阈值以及这些阈值在受试者之间的变异性随记录时间的增加而降低，并且听力受损者的阈值低于正常受试者。记录9.8分钟后，正常受试者的平均ASSR阈值（及标准差）为12.6 +/- 8.7，正常老年人为12.4 +/- 11.9dB，听力受损受试者为3.6 +/- 13.5dB SL。
