Kressner Abigail A, Rozell Christopher J
School of Electrical and Computer Engineering, 777 Atlantic Drive Northwest, Georgia Institute of Technology, Atlanta, Georgia 30332.
J Acoust Soc Am. 2015 Apr;137(4):2025-35. doi: 10.1121/1.4916271.
Although requiring prior knowledge makes the ideal binary mask an impractical algorithm, substantial increases in measured intelligibility make it a desirable benchmark. While this benchmark has been studied extensively, many questions remain about the factors that influence the intelligibility of binary-masked speech with non-ideal masks. To date, researchers have used primarily uniformly random, uncorrelated mask errors and independently presented error types (i.e., false positives and negatives) to characterize the influence of estimation errors on intelligibility. However, practical estimation algorithms produce masks that contain errors of both types and with non-trivial amounts of structure. This paper introduces an investigation framework for binary masks and presents listener studies that use this framework to illustrate how interactions between error types and structure affect intelligibility. First, this study demonstrates that clustering (i.e., a form of structure) of mask errors reduces intelligibility. Furthermore, while previous research has suggested that false positives are more detrimental to intelligibility than false negatives, this study indicates that false negatives can be equally detrimental to intelligibility when they contain structure or when both error types are present. Finally, this study shows that listeners tolerate fewer mask errors when both types of errors are present, especially when the errors contain structure.
尽管需要先验知识使得理想二值掩蔽成为一种不切实际的算法，但测量得到的可懂度大幅提高使其成为一个理想的基准。虽然对这个基准已经进行了广泛研究，但对于影响使用非理想掩蔽的二值掩蔽语音可懂度的因素，仍存在许多问题。迄今为止，研究人员主要使用均匀随机、不相关的掩蔽误差以及独立呈现的误差类型（即误报和漏报）来表征估计误差对可懂度的影响。然而，实际的估计算法产生的掩蔽包含这两种类型的误差，且具有相当数量的结构。本文介绍了一种针对二值掩蔽的研究框架，并展示了使用该框架的听众研究，以说明误差类型与结构之间的相互作用如何影响可懂度。首先，本研究表明掩蔽误差的聚类（即一种结构形式）会降低可懂度。此外，虽然先前的研究表明误报对可懂度的损害比漏报更大，但本研究表明，当漏报包含结构或两种误差类型都存在时，漏报对可懂度的损害可能同样严重。最后，本研究表明，当两种类型的误差都存在时，尤其是当误差包含结构时，听众能够容忍的掩蔽误差更少。
