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...     

不同通信系统下的说话人识别探究

目的研究不同通信系统条件下,利用语音进行说话人识别的基本假设＂个体之间的语音差异大于个体自身的语音变异＂是否成立。方法选择宽带语图差异较大的不同通信系统下语音进行比对及差异的统计。结果发现说话人识别的基本假设在不同通信系统条件下成立。结论得出了不同通信系统条件下进行说话人识别的方法与判阈。     

论声纹鉴定意见的表述形式

本文针对目前国内外讨论比较热烈的声纹鉴定意见表述问题进行了评述.首先介绍了实践中正在使用的听觉分析法、声谱比对分析法、声学分析法、听觉-声学分析法和说话人自动识别五种鉴定方法,指出了各种方法的优缺点;然后对现存的二元判决、可能性等级、似然比和英国立场声明四种鉴定意见表述形式进行了介绍和评析,通过分析发现,上述四种意见表述形式都存在一定的问题,实践中选择何种形式表述鉴定意见要综合考虑其科学性、逻辑性、现实性和可行性等多种价值选项;最后认为解决该问题的根本方法是各相关领域的专家应加强在鉴定方法上的合作性的基础研究.     

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。     

似然比在法庭说话人确认中的应用

本文把成功应用于DNA检验的证据评估方法（似然比）应用于法庭语音证据评估之中,提取语音的LPC作为识别特征,并使用45人电话对话录音中元音/a/作为样本进行了测试。结果表明该方法不仅能正确识别说话人,而且能根据当前嫌疑人样本和问题语音样本的差异,量化该语音样本作为证据的力度,为法庭提供科学合理的证据评估结果和科学解释。同时,自动特征提取的引入比起人工提取共振峰特征,提高了工作效率,识别系统性能也获得大幅提升。     

Forensic reference data on articulation rate in German.

Articulation rate (AR) is one of the parameters used in forensic voice comparisons for the purpose of providing evidence for or against speaker identity, yet at present multi-speaker studies on this parameter are very rare. In order to alleviate this situation AR was measured in the speech of 100 German-speaking male subjects. Histograms were provided from which the forensic expert can infer the percentages of different AR values in the population. Separate histograms were provided for mean AR and standard deviation of AR. It was also found that mean AR is significantly higher in read than spontaneous speech and that AR standard deviation is significantly smaller in read than spontaneous speech, although many individual speakers deviate from this general pattern.     

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.     

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。     

辨证认识话者自动识别系统

为了警示近年来我国司法话者识别领域中出现的一些崇外、盲目追求快速与省事的苗头,结合话者自动识别系统的研究、应用状况,从语音的共性与个性、话者识别结果的相对性与绝对性出发,通过分析比对话者自动识别与语音识别所用的特征参数及实现过程,辨证分析了制约话者自动识别系统准确率的根本原因。指出了话者自动识别系统尚无法达到人们对其的期望,以及适合于司法诉讼领域的话者自动识别系统的发展方向。     

法庭语音学

本文对法庭语音学进行了研究综述,主要介绍了该学科的核心内容：说话人鉴定。在实际办案中,当未找到嫌疑人,只有犯罪分子的检材语音时,可以使用说话人画像/说话人分类技术。若没有犯罪分子的录音证据时,可以让受害人和证人进行说话人的听觉辨认。具体的辨认形式有两种：对熟人辨认和对陌生人辨认,在对陌生人辨认时可以采用语音辨认的方法进行。当检材语音和样本语音都齐备的时候,法庭语音分析专家就可以对二者进行比对检验了。目前语音比对分析涉及到的问题和领域有：基于贝叶斯方法的法庭推理和似然比计算、共振峰频率的测量应用、非解析感知与样例理论、法庭说话人自动识别以及不同方法的综合应用等。     

伪装语音的自动话者识别研究

本文以语音自动话者识别系统为平台,对实际案件中出现频率较高的10种伪装语音类型进行自动话者识别测试。通过对20位发音人的正常语音和10种类型伪装语音的话者辨认和话者确认测试,分析不同语音伪装类型对自动话者识别的影响。该结果对于深入认识伪装语音的特性及其话者识别研究具有重要意义,也为自动话者识别技术的改进提供了参考。     

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 。     

声纹鉴定中的音强特征研究

目的 确定声纹鉴定中的音强特征的应用价值.方法 将10名条件相近、普通话较标准的男性发音人的语音样本输入VS-99型语音工作站,分别对每个人所发的相同音节韵母的宽带声纹图谱进行分析比对.结果 不同人发出的相同音节,其音强分布一般不同,有时还会出现明显的差异,主要表现在韵母总体音强按频率分布状态、韵母总体音强按时间分布状...     

Speech Watermarking: An Approach for the Forensic Analysis of Digital Telephonic Recordings*

Abstract: In this article, the authors discuss the problem of forensic authentication of digital audio recordings. Although forensic audio has been addressed in several articles, the existing approaches are focused on analog magnetic recordings, which are less prevalent because of the large amount of digital recorders available on the market (optical, solid state, hard disks, etc.). An approach based on digital signal processing that consists of spread spectrum techniques for speech watermarking is presented. This approach presents the advantage that the authentication is based on the signal itself rather than the recording format. Thus, it is valid for usual recording devices in police‐controlled telephone intercepts. In addition, our proposal allows for the introduction of relevant information such as the recording date and time and all the relevant data (this is not always possible with classical systems). Our experimental results reveal that the speech watermarking procedure does not interfere in a significant way with the posterior forensic speaker identification.     

法庭语音学

本文对法庭语音学进行了研究综述,主要介绍了该学科的核心内容:说话人鉴定。在实际办案中,当未找到嫌疑人,只有犯罪分子的检材语音时,可以使用说话人画像/说话人分类技术。若没有犯罪分子的录音证据时,可以让受害人和证人进行说话人的听觉辨认。具体的辨认形式有两种:对熟人辨认和对陌生人辨认,在对陌生人辨认时可以采用语音辨认的方法进行。当检材语音和样本语音都齐备的时候,法庭语音分析专家就可以对二者进行比对检验了。目前语音比对分析涉及到的问题和领域有:基于贝叶斯方法的法庭推理和似然比计算、共振峰频率的测量应用、非解析感知与样例理论、法庭说话人自动识别以及不同方法的综合应用等。     

Voice disguise and automatic speaker recognition

In this paper a newly developed Forensic Automatic Speaker Recognition System (FASRS) was introduced and the effect of 10 types of voice disguises that are common in forensic casework on the performance of this system was studied. In this study 10 types of disguised voices and normal voices from 20 male college students were used as test samples. Each disguised voice was compared with all normal voices in the database to make speaker identification and speaker verification. The result of speaker recognition is summarized and the influence of voice disguises on the FASRS is evaluated.     

再看摹仿签名笔迹鉴定

由于签名笔迹字数少、可摹仿性强的特点,长期以来,摹仿签名笔迹鉴定始终是笔迹鉴定的难点。笔者从不同类型的摹仿方法出发,讨论不同方法下摹仿签名笔迹的特点,总结其特征规律。同时要重视笔迹鉴定过程中了解相关案情,为识别是否存在摹仿现象提供线索。在此基础之上,对比摹仿签名笔迹特征的变化规律,并从摹仿签名笔迹特征反映构成方面系统性地进行鉴定,鉴别是否存在摹仿签名的情况。通过撰写此文,以期对摹仿签名笔迹鉴定实务具有借鉴意义。     

认识非语音信息在司法话者识别中的应用

通过介绍两起利用非语音信息最终辅助确认了说话人的司法话者识别检验案件,发现在说话人识别中,当待检语音无法满足语图比对条件时,充分利用非语音信息所揭示出的个体特性将有助于解决话者识别问题。得出了当待检语音条件不充分时,依靠非语音信息来辅助进行话者识别的方法。     

The Lateral Angle Revisited: A Validation Study of the Reliability of the Lateral Angle Method for Sex Determination Using Computed Tomography (CT),

This article presents the results of a validation study of a previously published method of sex determination from the temporal bone. The purpose of this study was to evaluate the lateral angle method for the internal acoustic canal for accurately determining the sex of human skeletal remains using measurements taken from computed tomography (CT) scans. Previous reports have observed that the lateral angle size in females is significantly larger than in males. The method was applied to an independent series of 77 postmortem CT scans (42 males, 35 females) to validate its accuracy and reliability. The mean lateral angle of the internal acoustic canal was found to be larger in females (46.5°) than in males (43.4°). However, the difference was not statistically significant and the sex differences reported in previous studies were not substantiated. In light of the observed results, the lateral angle method appears to be of minimal practical use in forensic anthropology and archeology.     

Major incident response: collecting ante-mortem data

The Asian tsunami of 26 December 2004, which devastated coastal parts of more than 10 countries in and around the Indian Ocean caused over 200,000 casualties. People from more than 58 nationalities were amongst the victims and subsequently an international effort for disaster victim identification (DVI) was set up, coordinated by Interpol. DVI teams from more than 20 countries took part in the identification process which, because of the complexity of the situation, had to be conducted in an internationally agreed upon procedure. Standard operating protocols of post-mortem (PM) procedures were established for fingerprinting, forensic pathology, forensic odontology and DNA profiling and were crucial in the quality of the entire DVI process of the quickly decomposing bodies. A very important and underestimated part of the DVI process is the gathering of the ante-mortem (AM) data of the persons reported missing in their home countries. In the wake of this tsunami event it appeared to be even more problematic as entire families had died and information was difficult to obtain. As dentistry proved to be the most valuable identification mean--up to 85% of the cases--the AM dental records proved to be crucial elements for DVI. Standard operating protocols (SOP) were again established as to who, where, when and what information had to be collected by the dentists by the AM teams abroad. Transcribing the AM dental information by experienced forensic odontologists was another crucial element in the whole identification procedure as the information had to be loaded into the DVI System International (Plass Data, Holbaek, Denmark) for comparison with incoming PM data. The Interpol DVI Standing Committee thus recommends that forward planning, adequate funding, international cooperation and standardisation are essential to guarantee an effective response to any major mass disaster of this kind in the future.