Minimum mean-square error (MMSE) approaches to speech enhancement are widely used in the literature. The quality of enhanced speech produced by an MMSE approach is directly impacted by the accuracy of the employed a priori signal-to-noise ratio (SNR) estimator. In this paper, the a priori SNR estimate spectral distortion (SD) level that results in a just-noticeable difference (JND) in the perceived quality of MMSE approach enhanced speech is found. The JND SD level is indicative of the accuracy that an a priori SNR estimator must exceed to have no impact on the perceived quality of MMSE approach enhanced speech. To measure the JND SD level, listening tests are conducted across five SNR levels, five noise sources, and two MMSE approaches [the MMSE short-time spectral amplitude (MMSE-STSA) estimator and the Wiener filter]. A statistical analysis of the results indicates that the JND SD level increases with the SNR level, is higher for the MMSE-STSA estimator, and is not impacted by the type of background noise. Following the literature, a significant improvement in a priori SNR estimation accuracy is required to reach the JND SD level.

中文翻译：

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频谱失真水平导致先验信噪比估计值与瞬时情况之间的差异明显

用于语音增强的最小均方误差（MMSE）方法已在文献中广泛使用。MMSE方法产生的增​​强语音的质量直接受到所采用的先验信噪比（SNR）估计器准确性的影响。在本文中，发现了先验SNR估计频谱失真（SD）级别，该级别会导致MMSE方法增强语音的感知质量产生明显的差异（JND）。JND SD级别指示先验精度SNR估算器必须超过MMSE方法增强的语音感知质量。为了测量JND SD级别，在五个SNR级别，五个噪声源和两个MMSE方法[MMSE短时频谱幅度（MMSE-STSA）估计器和Wiener滤波器]上进行了监听测试。结果的统计分析表明，JND SD级别随SNR级别而增加，对于MMSE-STSA估计器而言更高，并且不受背景噪声类型的影响。根据文献，需要达到先验SNR估计精度的显着提高才能达到JND SD级别。