飞机舱音背景声下语音增强技术

Speech enhancement technique in aircraft cockpit voice background

有效提取飞机舱音背景声下的语音信息对飞行事故调查十分重要。提出一种适用于飞机座舱噪声环境下的语音增强方法。以卡方分布作为纯语音谱幅值的先验模型,采用最小均方误差短时谱估计法对带噪语音中的纯语音谱进行估计,误差估计方程中采用权值函数对估计值进行非线性加权。在仿真试验中利用语音质量的客观评价标准选取适合于舱音背景声下的纯语音谱估计参数,使增强语音中噪声抑制和语音失真之间达到平衡。最后将提出的语音增强方法与目前典型方法进行了对比实验,验证算法的有效性。

For flight accident investigation it is very important to efficiently extract the speech information against aircraft cockpit voice background.A speech enhancement method suited to the case of aircraft cockpit voice background was proposed.CHI PDF was chosen as the prior distribution for the statistical model of clean speech spectral magnitude;the minimum mean-square error short time spectral amplitude (MMSE-STSA) estimator was utilized to estimate the clean speech spectral magnitude;and a share function was used to give different emphasis on errors of small amplitudes relative to large amplitude in the error estimation function.In order to achieve the balance between noise reduction and speech distortion,the parameters in clean speech spectral estimation were chosen against the cockpit voice background by simulation experiments incorporating with the objective assessment of speech quality.Finally,in order to validate the effectiveness of proposed method,the comparison experiments between the classic methods and the proposed method were carried out.