Most noise reduction algorithms rely on obtaining reliable estimates of the SNR of each frequency bin. For that reason, much work has been done in analyzing the behavior and performance of SNR estimation algorithms in the context of improving speech quality and reducing speech distortions (e.g., musical noise). Comparatively little work has been reported, however, regarding the analysis and investigation of the effect of errors in SNR estimation on speech intelligibility. It is not known, for instance, whether it is the errors in SNR overestimation, errors in SNR underestimation, or both that are harmful to speech intelligibility. Errors in SNR estimation produce concomitant errors in the computation of the gain (suppression) function, and the impact of gain estimation errors on speech intelligibility is unclear. The present study assesses the effect of SNR estimation errors on gain function estimation via sensitivity analysis. Intelligibility listening studies were conducted to validate the sensitivity analysis. Results indicated that speech intelligibility is severely compromised when SNR and gain over-estimation errors are introduced in spectral components with negative SNR. A theoretical upper bound on the gain function is derived that can be used to constrain the values of the gain function so as to ensure that SNR overestimation errors are minimized. Speech enhancement algorithms that can limit the values of the gain function to fall within this upper bound can improve speech intelligibility.

大多数降噪算法依赖于获得每个频率仓的 SNR 的可靠估计。出于这个原因，在提高语音质量和减少语音失真（例如，音乐噪声）的背景下，在分析 SNR 估计算法的行为和性能方面已经做了很多工作。然而，关于 SNR 估计中的误差对语音清晰度的影响的分析和调查的报告相对较少。例如，不知道是 SNR 高估错误、SNR 低估错误还是两者都对语音清晰度有害。SNR 估计中的误差会在增益（抑制）函数的计算中产生伴随误差，并且增益估计误差对语音清晰度的影响尚不清楚。本研究通过灵敏度分析评估 SNR 估计误差对增益函数估计的影响。进行了可理解性听力研究以验证敏感性分析。结果表明，当 SNR 和增益高估误差被引入具有负 SNR 的频谱分量时，语音清晰度会受到严重影响。推导出增益函数的理论上限，该上限可用于约束增益函数的值，以确保最小化 SNR 高估误差。可以将增益函数的值限制在此上限内的语音增强算法可以提高语音清晰度。进行了可理解性听力研究以验证敏感性分析。结果表明，当 SNR 和增益高估误差被引入具有负 SNR 的频谱分量时，语音清晰度会受到严重影响。推导出增益函数的理论上限，该上限可用于约束增益函数的值，以确保最小化 SNR 高估误差。可以将增益函数的值限制在此上限内的语音增强算法可以提高语音清晰度。进行了可懂度听力研究以验证敏感性分析。结果表明，当在具有负 SNR 的频谱分量中引入 SNR 和增益高估误差时，语音清晰度会受到严重影响。推导出增益函数的理论上限，该上限可用于约束增益函数的值，以确保最小化 SNR 高估误差。可以将增益函数的值限制在此上限内的语音增强算法可以提高语音清晰度。推导出增益函数的理论上限，该上限可用于约束增益函数的值，以确保最小化 SNR 高估误差。可以将增益函数的值限制在此上限内的语音增强算法可以提高语音清晰度。推导出增益函数的理论上限，该上限可用于约束增益函数的值，以确保最小化 SNR 高估误差。可以将增益函数的值限制在此上限内的语音增强算法可以提高语音清晰度。