Jakimetz J J, Silman S, Miller M H, Silverman C A
New York University, New York 10003.
J Acoust Soc Am. 1989 Nov;86(5):1783-9. doi: 10.1121/1.398610.
The acoustic-reflex thresholds (ART) for multicomponent tonal complexes of varying bandwidth and spectral density were obtained from 20 normal-hearing (air-conduction thresholds less than or equal to 20 dB HL at 250-8000 Hz) young adults ranging in age from 20-30 years and 20 normal-hearing, old subjects ranging in age from 60-71 years. The results revealed that the ART decreased with spectral density, plateauing after seven components in the young group and after five components in the old group; the decrease in the acoustic-reflex threshold as a result of the increase in spectral density was less in the old than in the young group. The bandwidth effect (when bandwidth was plotted in hertz or octaves) on the acoustic-reflex threshold was present in the young adults, but substantially reduced in the elderly, as evidenced by the statistically significant interaction between subject group and signal bandwidth. The spectral density results are discussed in terms of their theoretic implications for the energy summation capacity and frequency resolution of the auditory system. The bandwidth results are discussed in terms of their theoretic implications for the frequency-resolving power of the auditory system.
从20名年龄在20至30岁之间听力正常（250 - 8000赫兹气导阈值小于或等于20分贝听力级）的年轻成年人以及20名年龄在60至71岁之间听力正常的老年受试者身上获取了不同带宽和频谱密度的多成分音调复合体的听反射阈值（ART）。结果显示，听反射阈值随频谱密度降低，年轻组在七个成分后趋于平稳，老年组在五个成分后趋于平稳；由于频谱密度增加导致的听反射阈值下降在老年组比在年轻组要小。年轻成年人存在听反射阈值的带宽效应（当带宽以赫兹或倍频程绘制时），但在老年人中大幅降低，这由受试者组和信号带宽之间具有统计学意义的相互作用证明。根据其对听觉系统能量总和能力和频率分辨率的理论意义讨论了频谱密度结果。根据其对听觉系统频率分辨能力的理论意义讨论了带宽结果。
