Department of Psychology, University of Minnesota, Minneapolis, MN 55455, USA.
Adv Exp Med Biol. 2013;787:167-74. doi: 10.1007/978-1-4614-1590-9_19.
Auditory enhancement refers generally to the increased perceptual salience of a spectral region when that region is preceded by its spectral complement, e.g., reinserting a missing component in a harmonic complex makes that component "pop out." One manifestation of enhancement is the increased detectability of a signal in certain spectro-temporal configurations. In the present experiments, detection thresholds were measured for a 2-kHz signal that was masked by an inharmonic complex with a spectral notch centered at 2-kHz. When the masker was preceded by a precursor/adaptor with a spectral gap identical to that of the masker, detection thresholds were lowest when the gap width was 0.6 octave. The amount of signal enhancement, the difference in thresholds between the no-precursor and precursor -conditions, decreased for smaller and larger gap widths. In addition, this general result was robust for precursors such as band-reject noise and harmonic complexes that were different in perceptual quality from the masker. This suggests that grouping/segregation processes do not mediate enhancement as assessed here. Similarly, significant enhancement was observed with precursor-masker level differences over a 40-dB range. Overall, these results further indicate that frequency resolution is a dynamic process that depends on spectro-temporal context. They also are consistent with a mechanism involving adaptation of inhibition that likely occurs at low levels in the auditory system.
听觉增强通常是指当一个光谱区域的光谱互补区域出现在其前面时，该区域的感知显著性增加，例如，在谐波复合体中重新插入缺失的成分会使该成分“突出”。增强的一种表现形式是在某些声谱时配置中信号的可检测性增加。在本实验中，测量了一个 2kHz 信号的检测阈值，该信号被一个中心在 2kHz 的非谐波复合体掩蔽。当掩蔽器前面有一个与掩蔽器光谱间隙相同的前导/适配器时，当间隙宽度为 0.6 个八度时，检测阈值最低。信号增强的幅度，即无前导和前导条件之间的阈值差异，随着间隙宽度的减小和增大而减小。此外，对于与掩蔽器在感知质量上不同的带阻噪声和谐波复合体等前导，这种一般结果是稳健的。这表明分组/分离过程不会像这里评估的那样介导增强。同样，在前导-掩蔽器电平差异在 40dB 范围内时，也观察到了显著的增强。总体而言，这些结果进一步表明，频率分辨率是一个依赖于声谱时上下文的动态过程。它们也与涉及抑制适应的机制一致，这种机制可能在听觉系统的较低水平发生。
