Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, University Kebangsaan Malaysia, Bangi, 43600, Malaysia.
Sensors (Basel). 2012;12(5):6727-45. doi: 10.3390/s120506727. Epub 2012 May 22.
In this paper, a variable threshold voice activity detector (VAD) is developed to control the operation of a two-sensor adaptive noise canceller (ANC). The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE) convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods.
本文提出了一种变门限语音活动检测器（VAD），用于控制双传感器自适应噪声消除器（ANC）的工作。VAD 禁止 ANC 的参考输入在自适应期间包含一定强度的实际语音信号。这种方法的新颖之处在于利用噪声消除器的剩余输出来控制 VAD 做出的决策。根据自适应滤波器的剩余输出，调整全频带能量和过零特征的门限。以信噪比提高和 ANC 的均方误差（MSE）收敛为指标，对所提出方法的性能进行了评估。在几种类型的环境噪声下进行测试时，新方法显示出了改进的噪声消除性能。此外，由于仅在非语音期间有效地计算自适应滤波器的输出，因此自适应过程的计算量减少。
