Detection and discrimination of frequency glides as a function of direction, duration, frequency span, and center frequency.
Detection and discrimination of frequency glides as a function of direction, duration, frequency span, and center frequency.
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DOI：
10.1121/1.420346
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发表时间：
1997-11
期刊：
影响因子：
--
通讯作者：
J. P. Madden;K. M. Fire
中科院分区：
文献类型：
--
作者：
J. P. Madden;K. M. Fire
这项研究调查了在各种实验条件下探测和辨别频率滑移的能力。受试者区分频率相同或被扫过固定频率范围的比较信号，以及频率变化比比较信号更大的目标信号。音调持续时间分别为50ms和400ms。标称中心频率为0.5、2和6 kHz；实际中心频率在等于标称中心频率0.1倍的范围内随机变化或漂移。使用了上下滑梯。在标称中心频率下，比较信号的转换跨度是听觉滤波器等效矩形带宽的0、0.5、1或2倍。获得了中心频率、方向和跨度的所有组合的辨别阈值。总体而言，以增量赫兹/ERB表示的阈值随着中心频率的变化很小。滑行持续时间对辨别能力没有影响。50ms的下滑波比50ms的上滑波更难探测到；否则，方向的影响不显著。除了50ms的下降外，0、0.5和1-ERB过渡跨度的检测/辨别阈值相似，但2-ERB跨度的检测/识别阈值显著增加。没有跨频率的显著变化支持基于对激励模式中的变化的检测来检测滑动音调中的频率变化的位置机制。然而，激励模式模型不能解释滑翔探测所注意到的不对称性。
The study investigated the ability to detect and discriminate frequency glides under a variety of experimental conditions. The subjects distinguished between a comparison signal that either was level in frequency or was swept across a fixed frequency span, and a target signal that changed more in frequency than the comparison signal. Tone durations were 50 and 400 ms. Nominal center frequencies were 0.5, 2, and 6 kHz; actual center frequencies were varied randomly, or roved, over a range equal to 0.1 times the nominal center frequency. Up- and down-glides were used. The transition span of the comparison signal was either 0, 0.5, 1, or 2 times the equivalent rectangular bandwidth of the auditory filter at the nominal center frequency. Discrimination thresholds were obtained for all combinations of center frequency, direction, and span. Overall, thresholds expressed as delta Hz/ERB varied little as a function of center frequency. Glide duration had no effect on discrimination. The 50-ms down-glides were more difficult to detect than the 50-ms up-glides; otherwise, the effect of direction was not significant. With the exception of the 50-ms down-glides, detection/discrimination thresholds were similar for the 0-, 0.5-, and 1-ERB transition spans, but increased significantly for the 2-ERB span. The absence of significant variation across frequency supports a place mechanism for the detection of frequency change in gliding tones, based on the detection of changes in the excitation pattern. An excitation pattern model cannot account for the asymmetry noted for glide detection, however.