Echo cancellation plays an important role in current Internet protocol（IP） based voice interactive systems. Voice state detection is an essential part in echo cancellation. It mainly comprises two parts： double tal...Echo cancellation plays an important role in current Internet protocol（IP） based voice interactive systems. Voice state detection is an essential part in echo cancellation. It mainly comprises two parts： double talk detection（DTD） and voice activity detection（VAD）. DTD is used to detect doubletalk and prevent filter divergence in the presence of near-end speech, and VAD is used to determine the near-end voice activity and output silence indicator when near-end is silent. However, DTD straightforwardly proceeded may mistakenly declare double talk under double silent condition, coefficients update under the far-end silence condition may lead to filter divergence, and current VAD algorithms may misjudge the residual echo from the near end to be far-end voice. Therefore, a voice detection algorithm combining DTD and far-end VAD is proposed. DTD is implemented when VAD declares far-end speech, filtering and coefficients update will be halted when VAD declares far-end silence, and the far-end VAD adopted is multi-feature VAD based on short-time energy and correlation. The new algorithm can improve the accuracy of DTD, prevent filter divergence, and exclude the circumstance that far-end signal only contains residual echo from near end. Actual test results show that the voice state decision of the new algorithm is accurate, and the performance of echo cancellation is improved.展开更多
介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放...介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放,从而桥接无线列调中的有线通信和无线通信,为DRTD系统的核心业务提供支撑。展开更多
基金supported by the National Youth Science Fund Project(61501052)the National Natural Science Foundation of China(61271182)
文摘Echo cancellation plays an important role in current Internet protocol（IP） based voice interactive systems. Voice state detection is an essential part in echo cancellation. It mainly comprises two parts： double talk detection（DTD） and voice activity detection（VAD）. DTD is used to detect doubletalk and prevent filter divergence in the presence of near-end speech, and VAD is used to determine the near-end voice activity and output silence indicator when near-end is silent. However, DTD straightforwardly proceeded may mistakenly declare double talk under double silent condition, coefficients update under the far-end silence condition may lead to filter divergence, and current VAD algorithms may misjudge the residual echo from the near end to be far-end voice. Therefore, a voice detection algorithm combining DTD and far-end VAD is proposed. DTD is implemented when VAD declares far-end speech, filtering and coefficients update will be halted when VAD declares far-end silence, and the far-end VAD adopted is multi-feature VAD based on short-time energy and correlation. The new algorithm can improve the accuracy of DTD, prevent filter divergence, and exclude the circumstance that far-end signal only contains residual echo from near end. Actual test results show that the voice state decision of the new algorithm is accurate, and the performance of echo cancellation is improved.
文摘介绍DRTD系统中无线列调语音业务的音频回放技术。DRTD系统有线通信基于SIP协议和R T P流进行音频传输,通过混音、加窗语音检测、缓存、格式转换、信令控制等处理流程,将音频流在无线空口上进行传输,并最终在移动终端上实现语音波形回放,从而桥接无线列调中的有线通信和无线通信,为DRTD系统的核心业务提供支撑。
