Experimental results show that the new vad algorithm improves g . 729 ' s overall performance in varying noisy situations . experimental results of comparing with other vad are also presented 结果证明该技术在白噪声环境下大部分性能比g . 729b (同样应用vad算法来改进g . 729的一个标准算法)优越。
Because of the large difference between spectrum of speech and noise and great ability of dct to reduce the correlation of signal , it is advantage to use dct domain spectral entropy to do vad 由于语音与噪音的频谱区别很大, dct去除信号相关性的能力很强,利用dct谱熵在噪声环境下进行语音检测有其独特的优势。
The noise estimation includes vad and updating noise spectrum continuously . the first one is complemented easily , the later aims at actual unstable noise and updates the noise spectrum continuously 噪声估计分为vad ( voiceactivitydetection )和连续更新噪声谱两种,前者实现简单,后者针对实际非平稳噪声和即时更新噪声。
As the pitch doubling and halving problems of nccf algorithm often occurred with varied noises and signal to noise ratio ( snr ) , vad algorithm is employed to separate speech and non - speech segments 针对nccf基音检测算法在不同噪声、信噪比下容易发生清浊误判的问题,本文在基音检测前端引入语音检测算法划分语音段与非语音段。
The changes of mean wind from low - level to high - level can be show from vad technique . we can get the mean wind of certain level only , but no the distributing at different azimuth . so we maybe ignored some local - system 由于vad方法只是揭示了平均风矢量从低空到高空的演变，得到的是各个高度层上的平均风场，无法得知各个高度层上的水平风场。
Experiment results show their shortages under varying noisy situations . chapter 4 and chapter 5 detail our new algorithm and its implementation . to overcome the traditional vad parameters " poor performance in non - stationary noise , a new vad algorithm based on lp residue is proposed in chapter 4 其中第四章通过分析语音信号参数的特点，以独创的基于线性预测残余信息的vad参数结合其他几种经典vad算法参数的优点，提出一种新的vad技术来改进现有的g . 729算法。
Experimental results in different noises and snr indicated that this vad algorithm can divide speech segments from non - speech segments accurately and reduce voiced - unvoiced error obviously . ( 2 ) an improved dct - hn speech decomposition algorithm based on the harmonic - noise model is presented 不同噪声、信噪比下的实验结果表明,该算法可以准确区分语音段与非语音段,明显降低了基音检测中清浊误判现象的发生; ( 2 )基于“谐波-噪声”模型提出了一种改进的dct - hn语音分解算法。
The research content of the thesis is the speech enhancement technique that is used in the acoustic feedback suppresser . firstly , we searched and compared the methods of noise estimation based on vad and updating the noise spectrum continuously , combined them together to make some improvement . secondly , we research on some speech enhance techniques including short time spectrum analysis speech enhance technique and its improvement form , simulated the algorithms and compared them each other 本论文研究语音增强技术在声反馈抑制器中的应用,论文的主要工作包括: 1 .对基于vad ( voiceactivitydetection )的噪声估计方法和连续更新噪声谱的方法进行研究和比较,针对仿真结果分析两种噪声估计的性能,并将两者结合起来,做出改进,用于实际的语音增强系统中。
Chapter one in this paper gives brief applications of doppler radar , analyses the techniques of wind retrieval ; the second part introduce the methods of dealiasing ; using vad technique , the environmental wind can be extracted . during actual operation , there are two kinds of practice strategies , one is single - elevation vad method , and the other is multi - elevation vad method . there are different between those two methods 第三章在几种vad算法中选择了一种较好的算法，分别用实际业务中使用的两种实施策略：单仰角vad方法和多仰角vad方法进行风场反演，比较了这两种算法的反演结果，并提出了融合这两种方法优点的自适应仰角取样策略。
However g . 729 ' s computation complexity is a little higher for application . taking the advantage of discontinuous transmission , we embed a new algorithm of voice active detection ( vad ) into the original algorithm of g . 729 to improve its efficiency . this algorithm can also reduce the average computation complexity of g . 729 本研究针对g . 729的特点，提出了一种新的语音激活检测算法，利用该算法对g . 729的不足之处进行改进，提高g . 729的算法效率，降低其平均运算时间，并将该算法用vhdl描述，兑现成硬件。
