Acoustics Research Institute, Austrian Academy of Sciences, Wohllebengasse 12-14, A-1040 Vienna, Austria.
J Acoust Soc Am. 2013 Aug;134(2):1160-71. doi: 10.1121/1.4812773.
Laback et al. [(2011). J. Acoust. Soc. Am. 129, 888-897] investigated the additivity of nonsimultaneous masking using short Gaussian-shaped tones as maskers and target. The present study involved Gaussian stimuli to measure the additivity of simultaneous masking for combinations of up to four spectrally separated maskers. According to most basilar membrane measurements, the maskers should be processed linearly at the characteristic frequency (CF) of the target. Assuming also compression of the target, all masker combinations should produce excess masking (exceeding linear additivity). The results for a pair of maskers flanking the target indeed showed excess masking. The amount of excess masking could be predicted by a model assuming summation of masker-evoked excitations in intensity units at the target CF and compression of the target, using compressive input/output functions derived from the nonsimultaneous masking study. However, the combinations of lower-frequency maskers showed much less excess masking than predicted by the model. This cannot easily be attributed to factors like off-frequency listening, combination tone perception, or between-masker suppression. It was better predicted, however, by assuming weighted intensity summation of masker excitations. The optimum weights for the lower-frequency maskers were smaller than one, consistent with partial masker compression as indicated by recent psychoacoustic data.
拉巴克等人 [(2011)。J. 声学学会 129,888-897] 研究了使用短高斯形状的音作为掩蔽和目标的非同时掩蔽的可加性。本研究涉及高斯刺激，以测量多达四个光谱分离掩蔽器组合的同时掩蔽的可加性。根据大多数基底膜测量结果，掩蔽器应该在线性特征频率 (CF) 处处理目标。假设目标的压缩，所有掩蔽器组合都应该产生过度掩蔽 (超过线性可加性)。对于一对位于目标两侧的掩蔽器的结果确实显示出过度掩蔽。过度掩蔽的量可以通过一个模型来预测，该模型假设在目标 CF 处的强度单位中对掩蔽器引起的激发进行求和，并使用来自非同时掩蔽研究的压缩输入/输出函数来压缩目标。然而，低频掩蔽器的组合显示出的过度掩蔽比模型预测的要少得多。这不能简单地归因于离频听力、组合音感知或掩蔽器之间的抑制等因素。然而，通过假设掩蔽器激发的加权强度求和，可以更好地预测这一点。对于低频掩蔽器，最佳权重小于一，这与最近的心理声学数据表明的部分掩蔽器压缩一致。
