语音同一性鉴定中同声同韵异调音节的可比性定性研究

目的明确利用同声同韵异调音节进行语音同一性鉴定的可行性。方法利用VS-99语音工作站对普通话同声同韵异调音节的共振峰等特性进行定性分析。结果得出了阳平音节韵母共振峰与上声音节韵母非嘎裂声处共振峰的可比性强,阴平音节韵母与去声音节韵母在前半部分共振峰的可比性强等一些规律性认识。结论为利用同声同韵异调音节进行语音同一性鉴定提供了客观依据。     

广州话语音声纹鉴定中的量化分析研究

本研究从一般元音(音节核心)的同一认定方法着手,着重从定量分析方面研究声学特征参量,把多元统计方法使用到声纹鉴定中。通过计算变异系数、相关系数、正态性检验、方差分析等基本统计分析,对于男性语音,制定了马氏距离判别数学模型,判对率达98.3%;对于女性语音,制定了费歇(Fisher)判别数学模型,判对率达93.5%。本研究解决了声纹鉴定对声学特征参量定量分析方面的问题,确定了判定阈值及鉴定所需音节数,提供了一种新的语音判别方法。     

日本人所说汉语普通话的口音特点探究

目的探讨日本人所说汉语普通话的口音特点。方法从二语习得及与汉语方言比较等角度,对日本人所说汉语普通话的语音、词汇、语法等方面表现出的口音特点进行探讨。结果分别从声母、韵母、声调特点;书写相同但意义完全不同词的误用,单个汉字写法相同而字序相反的双音节词的误用,近义词、量词、副词、介词、关联词、虚词、动宾搭配等使用不当;句子残缺与累赘、语序偏误等方面分析日本人所说汉语普通话口音特点时。结论此分析方法可以为司法实践中分析语音资料的说话人是否为日本人提供参考。     

声纹鉴定的应用研究

利用KAY5500语图仪的各项功能及这些功能对语音研究的作用,研究语音的声学特征,探讨语音同一认定的原理、方法,及声谱图反映出的表征语音声学特性的各声纹特征在声纹鉴定中价值。     

从话者识别角度认识山西汾城方言的紧喉音节

目的 明确山西汾城方言紧喉音节与对应普通话音节在司法话者识别时的可比性及该紧喉音的声学特性.方法 利用VS-99语音工作站对山西汾城方言紧喉音节及对应普通话音节的韵律特性、音质特性等声学特性进行定性与定量分析.结果 得出了汾城方言紧喉音的发声态主要为嘎裂声,汾城方言紧喉音对声母没有明显影响,紧喉音韵母与普通话韵母在共振峰频率上的一致性要远高于共振峰相对强度上的一致性等认识.结论 为在汾城方言与普通话之间进行司法话者识别以及田野调查提供了依据.     

正常、大声两种说话状态下语音的声学差异及对声纹鉴定的影响

本文主要通过对正常、大声两种说话状态下的普通话中三个单元音[a]、[i]、[u]的声强、时长、基频、谐波振幅差值、共振峰等声学参数的分析,综合比较了各参数的变化规律,发现大声说话时的语音并非正常语音的简单放大,二者不仅在声强上存在差别,同时在频率域上也发生了重要变化。同一人不同状态下发音的频谱特征差异性较大,同种状态下发音的相似性、可比性较强,为此,声纹鉴定中应尽量选取状态相同的语音进行比对。     

声纹鉴定中普通话音素间过渡方式特征研究

不同人所讲的普通话语流中相邻音素间的过渡方式分为不同的类型。音节内辅音-元音之间、音节间元音-辅音之间的过渡方式分为清晰过渡(或停顿过渡)和模糊过渡(或缓冲过渡)两种类型;音节内元音-辅音之间的过渡方式分为间断过渡和连续过渡两种类型;音节内元音-元音之间的过渡方式分为平滑过渡、间断过渡、交错过渡和异变过渡四种类型。对同一人的发音而言,不论其相邻音素间的过渡方式属于上述哪种类型,都表现出较强的自身同一性。因此音素间的过渡方式可以作为声纹鉴定中的一类特征。     

正常、大声两种说话状态下语音的声学差异及对声纹鉴定的影响

本文主要通过对正常、大声两种说话状态下的普通话中三个单元音[a]、[i]、[u]的声强、时长、基频、谐波振幅差值、共振峰等声学参数的分析,综合比较了各参数的变化规律,发现大声说话时的语音并非正常语音的简单放大,二者不仅在声强上存在差别,同时在频率域上也发生了重要变化。同一人不同状态下发音的频谱特征差异性较大,同种状态下发音的相似性、可比性较强,为此,声纹鉴定中应尽量选取状态相同的语音进行比对。     

白噪声不同信噪比对语音基音和共振峰的影响研究

目的研究不同强度白噪声对语音特征提取的影响,总结变化规律,为带噪语音的声纹鉴定提供参考。方法对TIMIT连续语音语料库中的录音样本加载不同强度白噪声,使用语音工作站提取纯净语音、不同信噪比带噪语音的基频、共振峰,研究分析白噪声对语音特征参数的影响。结果低噪环境下,语音共振峰相对稳定,增大噪声强度,共振峰出现偏移或者无法检出现象;各阶共振峰抗噪能力不同,低阶共振峰抗噪声能力强,稳定度高,高阶共振峰抗噪能力弱,稳定性差,低阶共振峰抗噪能力优于高阶共振峰;基音在各种噪声强度下稳定度高,具备较强鲁棒性。结论信噪比降低会引起共振峰频率偏移,甚至丢失共振峰;噪声对高阶共振峰影响大于低阶共振峰;基频在噪声环境下具备较高的抗干扰能力,声纹鉴定中应重点分析噪声对语音特征的影响。     

不同手机及不同通信网络通话录音质量评析

目的为送检手机通话录音质量的审查提供理论依据。方法提出一种定量化的语音检材质量评价标准,并对不同手机及不同通信网络下的录音进行质量评价。该标准基于主流鉴定设备,涵盖了声学语谱图共振峰个数及数值、基频参数、区域平均频谱等分析方法以及声纹比对测试。结果实验结果显示,不同条件下得到的通话录音质量存在一定的差异性,会对声纹图谱鉴定产生一定影响,但并不会造成本质性差异。结论语音同一认定中,对基于移动通信网络获取的检材录音应考虑到通话语音质量的差异性对检验的影响,并在鉴定分析中加以评估和克服。     

女性普通话塞音过渡音征个体特性初探

目的考察塞音过渡音征的个体特性及在说话人鉴定中的价值。方法选取9位女性发音人普通话中的6个塞音与元音/i、a、u/组成的单音节,提取每个音节F2、F3的起点值和目标值进行统计分析,并计算说话人的塞音音轨。结果 （1）过渡音征形态特征在不同说话人之间具有差异;（2）各音节的说话人区分率呈现较大区别,音节/tu/的说话人区分率较高而/khu/音节几乎不具备说话人区分能力;（3）与零声母音节相比,音节中3个元音的F2共振峰频率均值受到塞音的影响而提高,其中/i、a/F2提高的幅度要大于/u/;（4）不同说话人的音轨存在差异。结论在说话人鉴定中选取塞音音节进行比对时要注意不同音节的说话人区分率,尽量避免选取舌根塞音音节;塞音过渡音征的形态和音轨数据可以应用于说话人鉴定。     

声纹鉴定中普通话音素间过渡方式特征研究

不同人所讲的普通话语流中相邻音素间的过渡方式分为不同的类型.音节内辅音-元音之间、音节间元音-辅音之间的过渡方式分为清晰过渡(或停顿过渡)和模糊过渡(或缓冲过渡)两种类型;音节内元音-辅音之间的过渡方式分为间断过渡和连续过渡两种类型;音节内元音-元音之间的过渡方式分为平滑过渡、间断过渡、交错过渡和异变过渡四种类型.对同...     

Intra- and inter-speaker variations of formant pattern for lateral syllables in Standard Chinese

Speech variation of speakers is a crucial issue for speaker recognition and identification, especially for forensic practice. Greater intra-speaker variation is one main reason for incorrect speaker identification in real forensic situations. Understanding the stability of acoustic parameters and their variation in speech is therefore significant for the evaluation of effective parameters for speaker identification. In this paper, all vowels in Standard Chinese including five monophthongs, eight diphthongs and four triphthongs were combined with lateral /l/. Finally, 15 lateral syllables with different tones for 10 speakers were selected and acoustically analyzed. Central frequencies of the first four formants for each syllable were measured for quantitative comparison of intra- and inter-speaker variation in order to provide a general idea of speaker variation in Standard Chinese, and finally serving for forensic application. Results show that the overall intra-speaker variation is less than the inter-speaker variation in great extent under laboratory condition though occasionally they are contrary. This supports the basis for forensic speaker identification, that is, intra-speaker variation should be less than inter-speaker variation in many acoustic features, and further validates the probability and reliability of forensic speaker identification.     

Effects of language mismatch in automatic forensic voice comparison using deep learning embeddings

In forensic voice comparison, deep learning has become widely popular recently. It is mainly used to learn speaker representations, called embeddings or embedding vectors. Speaker embeddings are often trained using corpora mostly containing widely spoken languages. Thus, language dependency is an important factor in automatic forensic voice comparison, especially when the target language is linguistically very different from that the model is trained on. In the case of a low-resource language, developing a corpus for forensic purposes containing enough speakers to train deep learning models is costly. This study aims to investigate whether a model pre-trained on multilingual (mostly English) corpus can be used on a target low-resource language (here, Hungarian), not represented by the model. Often multiple samples are not available from the offender (unknown speaker). Samples are therefore compared pairwise with and without speaker enrollment for suspect (known) speakers. Two corpora are used that were developed especially for forensic purposes and a third that is meant for traditional speaker verification. Speaker embedding vectors are extracted by the x-vector and ECAPA-TDNN techniques. Speaker verification was evaluated in the likelihood-ratio framework. A comparison is made between the language combinations (modeling, LR calibration, and evaluation). The results were evaluated by Cllr_min and EER metrics. It was found that the model pre-trained on a different language but on a corpus with a significant number of speakers can be used on samples with language mismatch. Sample duration and speaking style also seem to affect the performance.     

汉语普通话音高模式在话者鉴别中的应用

汉语普通话是声调语言,不同话者在基频水平和声调变化规律方面存在差异。本文利用常规软件分析不同话者的基频数据变化规律,经过归一化和多次曲线拟合后,形成具有明显形态特征的音高模式曲线。通过比对分析音高模式曲线的形态和模式参数差异,可以帮助实现话者鉴别的目的 。     

Forensic characterization of HDPE pipes by DSC

The melting behavior of 28 high density polyethylene (HDPE) pipe samples manufactured and supplied by 13 different manufacturers in India was examined by 'differential scanning calorimetry (DSC)' to find out if this parameter could be used in differentiating between these HDPE pipe samples which are chemically the same and being manufactured by different manufacturer. The results indicate that the melting temperature may serve as the useful criteria for differentiating HDPE (i) pipe samples from different sources and (ii) samples of different diameter from the same source.     

Linguistic Justice in International Law: An Evaluation of the Discursive Framework

Claims by minority groups to use their own languages in different social contexts are often presented as claims for “linguistic justice”, that is, justice as between speakers of different languages. This article considers how the language of international law can be used to advance such claims, by exploring how international law, as a discourse, approaches questions of language policy. This analysis reveals that international legal texts structure their engagement with “linguistic justice” around two key concepts: equality and culture. Through a close examination of the way in which these concepts function within international legal discourse, the article suggests that this conceptual framework may sometimes constrain, as well as enlarge, the possibilities for justice for minority language speakers. Thus while international law may provide a language for challenging injustices in the linguistic sphere, limitations inherent in this discourse may also restrict its emancipatory potential.     

Repeatability and reproducibility of earprint acquisition

For all forensic disciplines dealing with identification -- e.g., of glass, tool marks, fibers, faces, fingers, handwriting, speakers -- in which manual (subjective, nonautomated) processes play a role, operator dependencies are relevant. With respect to earprint identification, in the period 2002-2005, the Forensic Ear Identification research project collected a database of 1229 donors, three prints per ear, and laid down a "best practice" for print acquisition. Repeatability and reproducibility aspects of the print acquisition are tested. The study suggests that different operators may acquire prints of differing quality, with equal error rates of the matching system ranging from 9% to 19%. Moreover, it turns out that "matching" earprints are more alike when taken in a consecutive row than when taken on separate occasions. This underlines the importance of (1) studying operator effects, (2) operator training, and (3) not gathering "matching" reference material at the same occasion.