Clinical Psychoacoustics Laboratory, Department of Otolaryngology, University of Minnesota, MMC396, 420 Delaware Street SE, Minneapolis, Minnesota 55455, USA.
J Acoust Soc Am. 2011 Jul;130(1):364-75. doi: 10.1121/1.3589255.
Spectral ripple discrimination thresholds were measured in 15 cochlear-implant users with broadband (350-5600 Hz) and octave-band noise stimuli. The results were compared with spatial tuning curve (STC) bandwidths previously obtained from the same subjects. Spatial tuning curve bandwidths did not correlate significantly with broadband spectral ripple discrimination thresholds but did correlate significantly with ripple discrimination thresholds when the rippled noise was confined to an octave-wide passband, centered on the STC's probe electrode frequency allocation. Ripple discrimination thresholds were also measured for octave-band stimuli in four contiguous octaves, with center frequencies from 500 Hz to 4000 Hz. Substantial variations in thresholds with center frequency were found in individuals, but no general trends of increasing or decreasing resolution from apex to base were observed in the pooled data. Neither ripple nor STC measures correlated consistently with speech measures in noise and quiet in the sample of subjects in this study. Overall, the results suggest that spectral ripple discrimination measures provide a reasonable measure of spectral resolution that correlates well with more direct, but more time-consuming, measures of spectral resolution, but that such measures do not always provide a clear and robust predictor of performance in speech perception tasks.
在 15 名使用宽带（350-5600 Hz）和倍频程噪声刺激的人工耳蜗植入者中测量了光谱纹波鉴别阈值。将结果与先前从同一受试者获得的空间调谐曲线（STC）带宽进行比较。空间调谐曲线带宽与宽带光谱纹波鉴别阈值没有显著相关性，但与波纹噪声限制在以 STC 的探头电极频率分配为中心的 1 个倍频程通带内时的波纹鉴别阈值显著相关。还在 4 个连续倍频程中测量了倍频程刺激的波纹鉴别阈值，中心频率从 500 Hz 到 4000 Hz。在个体中发现阈值随中心频率有很大变化，但在汇总数据中没有观察到从顶点到基部分辨率增加或减少的一般趋势。在本研究的受试者样本中，无论是纹波还是 STC 测量都与噪声和安静环境下的语音测量没有一致的相关性。总体而言，结果表明光谱纹波鉴别测量提供了一种合理的光谱分辨率测量方法，与更直接但更耗时的光谱分辨率测量方法相关性良好，但这些测量方法并不总是能清楚且稳健地预测语音感知任务的表现。
