Speech enhancement algorithm for cochlear implants to suppress multi-directional speech noise
GONG Qin1,2, RAO Cheng1, ZHENG Shuo1
1. Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China; 2. Research Center of Biomedical Engineering, Wuxi Research Institute of Applied Technologies, Tsinghua University, Wuxi 214000, China
摘要在复杂声音场景,尤其是多人对话交谈的情况中,人工耳蜗佩戴者的言语可懂度会显著下降。该文提出了一种基于近距离双麦克风的语音增强算法,通过提取采集信号的延迟参数,并根据该参数设置掩蔽矩阵,进而区分不同方位的声源,抑制竞争性语音噪声。同时还以数字信号处理器(digital signal processor,DSP)为核心,搭建调试平台,对算法进行了工程实现。实际测试表明,算法提升了前端信号的信噪比,鲁棒性强,并且算法单帧运行时间短,可以和常用的人工耳蜗言语编码策略相融合,满足人工耳蜗的实时计算需求。
Abstract:Cochlear implant users often cannot clearly hear sounds in complex sound environments, especially with competing talkers. This paper describes a speech enhancement algorithm based on closely-spaced microphones. The algorithm extracts a delay parameter and defines a mask matrix based on this parameter to distinguish sound sources having different orientations. The model uses a digital signal processor (DSP) to implement the algorithm. Tests indicate that the robust algorithm improves the signal-to-noise ratio. The algorithm has short single-frame run times and can be integrated with commonly used speech coding strategies, which are needed for real-time computing in cochlear implants.
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