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标题: Research on Voiceprint Recognition System and Pattern Recognition Algorithm  [查看完整版帖子] [打印本页]

时间:  2012-9-27 15:52
作者: qiu810     标题: Research on Voiceprint Recognition System and Pattern Recognition Algorithm

Research on Voiceprint Recognition System and Pattern Recognition Algorithm
ABSTRACT
The identity recognition technology based on biometric characteristics was an important issue in the recent international research. Voiceprint recognition, in which the identity of the speaker was determined by voice recognition, had the widespread application value in the fields of System Security Authentication, Judicial Identification, Electronic Interception,etc.
Voiceprint recognition which was a type of voice recognition can be classified into two categories, speaker verification and speaker identification from the view of application as well as recognition with relevant test and recogntion with irrelevant from the view of recognition condition. In voiceprint recognition individual information features were focused, ignoring the content of the voice signal. There were two key technologies in voiceprint which were feature extraction in which the speaker’s voice characteristics were described by the feature parameters extracted from the voice signal in acoustic or statistical terms, as well as recognition model by which robot could learn and memorize the speaker’s characteristics in order to realize the recognition of the speaker.
This paper demonstrated the principles of voiceprint recognition technology and emphasizes on studying as follows:
(1) Extraction of voice signal: keynote period, zero-crossing rate, brightness, Linear Prediction Coefficients, LPC, Linear Cepstral Prediction Coefficients, LPCC, Mel-Frequency Cepstrum Coefficients, MFCC, etc
(2) voiceprint recognition approaches and models: Gaussian Mixture Models, Implicit Markov Model, Vectorization Model, Artificial Neural Network(ANN) Model, Support Vector Machine Model.
The recognition effect of the existing algorithms is susceptible to environmental noise, voice variation and other factors. According to this problem, Basing on the existing voice pattern recognition technology, this paper improved the calculation method and did plenty of experiments (experiments use the voice data which is gathered under different noise environment of the early, middle and late periods of a day. And during the one-month voice collection, the person got bad cold caused voice variation.).  Experiment results showed that the improved algorithm can effectively overcome the impact of environment noises and voice variation. This paper did work as follows:
(1) MFCC extracted form voice characteristics was improved, while the impact on voice signal was reduced by applying frequency masking algorithm; The accuracy of calculation was resolved in LF, HF, MF respectively, in turn the recognition rate was improved to a certain extent.
(2) A novel method of Initial codebook selection was presented by improving Vector Quantization Model: With the Hypersphere Extreme Selection Method and the improved LBG algorithm, the produce of empty cell during the converging process was reduced with an effectively improved recognition rate.
(3) Applying Labview graphical programming into the system of voiceprint recognition, a graphical virtual instrument panel was established by using powerful graphical environment and hardware resources in order to realize the real time selection and analysis of voice signal and the modularization, intellectualization through other softwares  at the advantage of low cost, convenient analysis of statistic,good management.
KEY WORDS: Voiceprint Recognition; Mel-Frequency Cepstrum Coefficients; Vector Quantifying Model ; LabVIEW


时间:  2012-9-27 15:52
作者: qiu810

摘  要
基于生物特征的身份认证技术是当今国际上的重点研究内容,声纹识别是通过语音识别说话人的身份,在系统安全认证、金融服务、司法鉴定以及电子侦听等领域有着广泛的应用价值。
声纹识别是语音识别的一种,从应用角度可将声纹识别分为说话人确认和说话人辨认两种,从识别条件角度可将其分为与文本有关的说话人识别和与文本无关的说话人识别两类。声纹识别不注重语音信号中的内容,只注重语音信号中个人的信息特征。声纹识别有两个关键技术:首先是特征提取,从声学或统计学的角度在语音信号中提取特征参数描述说话人的声音特征;其次是识别模型,用机器学习模型去学习、记忆说话人特征,从而实现说话人的识别。
本文系统阐述了声纹识别技术的原理,并重点研究了:
(1) 语音特征提取:基音周期、过零率、明亮度、线性预测系数(Linear Prediction Coefficients,LPC)、线性预测倒谱系数(Linear Cepstral Prediction Coefficients,LPCC)、美尔频率倒谱系数(Mel-Frequency Cepstrum Coefficients,MFCC)等。
(2) 声纹识别模型:高斯混合模型、隐马尔可夫模型、矢量量化模型、人工神经网络模型、支持向量机模型。
现有算法的识别效果容易受环境噪声、语音变异等因素的影响,针对这一问题,本文在对现有声纹识别技术进行深入研究的基础上,对现有算法进行了改进,并进行了大量实验(实验所用语音数据是在不同环境噪声下分早、中、晚不同时间段所录制,进行了为期一个月的声音采集,期间有人患重感冒,声音发生变异)。实验结果表明,改进的算法能够有效克服环境噪声、语音变异带来的影响。具体做了以下几个方面的工作:
(1) 改进了语音特征提取中的美尔频率倒谱系数法,利用频率掩蔽算法减少了噪声信号对语音信号的影响;利用MFCC、IMFCC、MidMFCC分别解决低频、高频、中频段的计算精度问题,一定程度上提高了语音的识别率。
(2) 改进了矢量量化模型,提出了一种新的初始码本选择方法——超球面极值选择法,改进了LBG算法,有效的减少了收敛过程中空胞腔的产生,有效地提高了识别率。
(3) 把LabVIEW图形化编程应用到声纹识别系统中来,利用计算机强大的图形环境和硬件资源建立图形化的虚拟仪器面板,实现对语音信号的实时采集、分析等,可以利用软件实现仪器功能的模块化、智能化,使其具有低成本、数据分析便利和管理良好等优点。
关键词: 声纹识别;美尔频率倒谱系数;矢量量化模型;LabVIEW






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