共查询到19条相似文献，搜索用时 515 毫秒
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对语音信号的时域和频域进行分析,对小波分析的特点进行多分辨率分析,发现其具有分析时频和频域局部特征的能力,即在高频部分具有较高的时间分辨率和较低的频率分辨率,在低频部分具有较高的频率分辨率和较低的时间分辨率,可用于测量语音信号中夹带瞬态反常现象并展示其成分的情况。用小波变换的方法实现语音信号去噪增强,并在Matlab中进行了实验效果仿真,结果表明,该方法对语音信号的增强效果很好。 相似文献
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基音参数检测是对基音周期的估计分析,这在语音信号处理中特别是在语音识别、语音信号的合成、还有编码方面,都起着举足轻重的作用。倒谱法是频域估计法中相对成功的一种方法。本文在结合基于加窗语音的倒谱模型,分析模型的声门激励倒谱和声道脉冲响应倒谱的特点,根据其倒谱特征,改进基音检测算法,并取得良好的效果。 相似文献
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白绍光 《内蒙古科技与经济》2009,(14):70-71,73
文章重点讨论了数字信号的频谱,利用FFT（快速傅立叶变换）和Burg（伯格）函数的分析方法,基于MATLAB环境和TM S320C 54XDSP,分析平稳随机信号和实际的语音信号功率谱密度,以期在频域提取信号的特征。 相似文献
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《西藏科技》2020,(2)
藏语作为藏族人民的基本日常语言,具有很好的应用市场,同时也有越来越多的人们愿意学习藏语,更深入的了解藏族人民的生活及藏族的传统名族习俗。这使得研究藏语语音成为一种很重要的任务,首先要分析藏语的基本特征,及各相关参数。频域分析在语音技术研究中具有重要的意义,而藏语语音研究在国内正处于发展的良好契机,对藏语的频域分析自然是比较重要的。藏语语音识别目前正处于不断完善阶段,通过分析其他语言的语音识别技术可知,藏语的语音识别必定会产生很可观的社会效益和经济效益,也将是藏文信息化道路上不能缺少的一步。文章选取藏文辅音字母和简短的拉萨日常用语,主要做了以下的研究:先是研究藏语语音的的基本特征,其次使用MATLAB作为工具对特定语音进行的频域分析来获取基本的藏语音频特征。 相似文献
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本文以飞机颤振试飞试验信号噪声过大的问题为契点,通过对广义时频域滤波算法Morlet小波对扫频激励及其响应进行时频分析,利用该类信号聚焦于时频域特定区域的特性能有效提取真实响应信号达到信噪分离的功能在飞机试飞试验信号调制与采集系统中的应用分析,研究了一套适用于噪声环境的飞机颤振模态参数辨识方法以减小噪声对辨识结果的影响,设计一种针对扫频激励的具有扫频信号及其响应在砰幸频域分布较为集中的频滤波器,以有效去除噪声。 相似文献
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提出了一种基于感知域的鲁棒性语音认证算法,将语音的感知特性与签名算法相结合,在满足内容认证和身份认证的同时,能够有效地抵抗通信噪声微扰.算法基于语音的掩蔽效应和非线性效应等人耳感知特性,着重去除其时频域掩蔽阈值下的冗余信息,进行非线性滤波后提取感知参数,并运用改进的Rainbow算法对这些语音参数进行签名.实验证明,该算法的唯一性和针对通信噪声的鲁棒性都很好,兼有Rainbow签名的安全性保证,可以满足语音通信中的鲁棒性认证要求. 相似文献
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信息隐藏是20世纪90年代逐步兴起的研究课题。语音信号的不特定的静音间隔使得它比较于音乐等其他音频信号缺少了很大的隐藏空间,而语音信号的信息隐藏在Internet和有线与无线电话信道又有着很好的应用前景。提出一种语音信号的信息隐藏算法,能够在MFCC参数中隐藏秘密消息,语音的短时能量具有的较强的稳定性,可以保证隐藏和提取时的帧的同步,使得对应的提取算法可以准确地从隐藏的语音中恢复出信息。本方法可以适用于Internet信道和局域网络或高速网络中的语音应用。 相似文献
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《Journal of The Franklin Institute》1987,324(1):113-124
Most temporal signals of practical interest are nonstationary and need to be modeled using time-varying systems. In this paper a composite model for these signals is proposed which accounts for nonstationarities in the mean and the autocorrelation functions. Unbiased and consistent time-varying estimators for the mean and the variance functions are studied and used to produce zero-mean, constant-variance signals that can be modeled using autoregressive systems with time-varying coefficients. The identification of the coefficients is implemented recursively using the parameterization of the coefficients by a set of basis functions. We illustrate the application of the composite model in the analysis and synthesis of speech and in the estimation of instantaneous frequencies in radar return signals. 相似文献
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Recently the Wigner distribution has been shown to be a potentially useful tool for analysing the time varying frequency domain phenomenon. In this paper, some of the salient features of the Wigner distribution are presented; properties of this important discrete distribution are derived, and an efficient digital implementation is presented. Effective Wigner throughput rates, in excess of those obtainable with an equivalent length FFT, are shown to be feasible. In particular, the Wigner distribution is studied in the context of enhancing speech analysis and recognition systems. It is suggested that this class of distribution is consistent with the mechanics of human speech and, using experimentation, produces a very robust spectral signature. This enriched data space can be used to uncover some frequency domain attributes of human speech which may be lost using a discrete Fourier transform. 相似文献
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《Journal of The Franklin Institute》2007,344(3-4):180-195
Functional correlation between oscillatory neural and muscular signals during tremor can be revealed by coherence estimation. The coherence value in a defined frequency range reveals the interaction strength between the two signals. However, coherence estimation does not provide directional information, preventing the further dissection of the relationship between the two interacting signals. We have therefore investigated causal correlations between the subthalamic nucleus (STN) and muscle in Parkinsonian tremor using adaptive Granger autoregressive (AR) modeling. During resting tremor we analyzed the inter-dependence of local field potentials (LFPs) recorded from the STN and surface electromyograms (EMGs) recorded from the contralateral forearm muscles using an adaptive Granger causality based on AR modeling with a running window to reveal the time-dependent causal influences between the LFP and EMG signals in comparison with coherence estimation. Our results showed that during persistent tremor, there was a directional causality predominantly from EMGs to LFPs corresponding to the significant coherence between LFPs and EMGs at the tremor frequency; and over episodes of transient resting tremor, the inter-dependence between EMGs and LFPs was bi-directional and alternatively varied with time. Further time–frequency analysis showed a significant suppression in the beta band (10–30 Hz) power of the STN LFPs preceded the onset of resting tremor which was presented as the increases in the power at the tremor frequency (3.0–4.5 Hz) in both STN LFPs and surface EMGs. We conclude that the functional correlation between the STN and muscle is dynamic, bi-directional, and dependent on the tremor status. The Granger causality and time–frequency analysis are effective to characterize the dynamic correlation of the transient or intermittent events between simultaneously recorded neural and muscular signals at the same and across different frequencies. 相似文献
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短波是目前常用的远距离通信手段,发射功率、工作频率、调制度、调制失真、谐波抑制是短波电台的重要工作指标。针对某型短波电台对外接口少、检测指标多的要求,设计一套基于计算机GPIB总线通信的测试系统,通过实时采集射频、音频、调制等信号来分析指标参数,从而实现短波电台的指标的自动测试。 相似文献
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为了监测某区域某频率段内声波信号的强弱,提出一种以C8051F060为控制核心的声波信号采集系统的设计方案。采用压力场声波传感器将可识别的声波信号转换为适当幅度的电信号,该信号经过由程控滤波器地处理后直接送至带高速ADC的单片机进行处理,最后以SYG2401281图形点阵液晶为显示器件实现声波信号的实时显示。 相似文献
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The purpose of this paper is to extract features from vibration signals measured from motors subjected to accelerated bearing fluting aging and to detect the effects of bearing fluting at each aging cycle of induction motors. This trending of bearing degradation is achieved by monitoring the changes in the vibration signals at various sub-band levels. This is accomplished by the application of wavelet transforms and multi-resolution analysis in order to extract information from selected frequency bands with minimum signal distortion. 相似文献