Temporal Parameters of Spontaneous Speech in Forensic Speaker Identification in Case of Language Mismatch: Serbian as L1 and English as L2

Celem badania jest analiza możliwości identyfikacji mówcy kryminalistycznego i sądowego podczas zadawania pytań w różnych językach, z wykorzystaniem parametrów temporalnych. (wskaźnik artykulcji, wskaźnik mowy, stopień niezdecydowania, odsetek pauz, średnia czas trwania pauzy). Korpus obejmuje 10 mówców kobiet z Serbii, które znają język angielksi na poziomie zaawwansowanym. Patrametry są badane z wykorzystaniem beayesowskiego wzoru wskaźnika prawdopodobieństwa w 40 parach tcyh samych mówców i w 230 parach różnych mówców, z uwzględnieniem szacunku wskaźnika błędu, równiego wskaźnika błędu i Całościowego Wskaźnika Prawdopodobieństwa. badanie ma charakter pionierski w zakresie językoznawstwa sądowego i kryminalistycznego por1) ónawczego w parze jezyka serbskiego i angielskiego, podobnie, jak analiza parametrów temporalnych mówców bilingwalnych. Dalsze badania inny skoncentrować się na porównaniu języków z rytmem akcentowym i z rytmem sylabicznym. The purpose of the research is to examine the possibility of forensic speaker identification if question and suspect sample are in different languages using temporal parameters (articulation rate, speaking rate, degree of hesitancy, percentage of pauses, average pause duration). The corpus includes 10 female native speakers of Serbian who are proficient in English. The parameters are tested using Bayesian likelihood ratio formula in 40 same-speaker and 360 different-speaker pairs, including estimation of error rates, equal error rates and Overall Likelihood Ratio. One-way ANOVA is performed to determine whether inter-speaker variability is higher than intra- speaker variability across languages. The most successful discriminant is degree of hesitancy with ER of 42.5%/28%, (EER: 33%), followed by average pause duration with ER 35%/45.56%, (EER: 40%). Although the research features a closed-set comparison, which is not very common in forensic reality, the results are still relevant for forensic phoneticians working on criminal cases or as expert witnesses. This study pioneers in forensically comparing Serbian and English as well as in forensically testing temporal parameters on bilingual speakers. Further research should focus on comparing two stress-timed or two syllable-timed languages to test whether they will be more comparable in terms of temporal aspects of speech.

Identyfikacja parametrów czasowych mowy spontanicznej mówców kryminalistycznych w przypadku niedopasowania językowego: język serbski jako L1 i język angielski jako L2

The purpose of the research is to examine the possibility of forensic speaker identification if question and suspect sample are in different languages using temporal parameters (articulation rate, speaking rate, degree of hesitancy, percentage of pauses, average pause duration). The corpus includes 10 female native speakers of Serbian who are proficient in English. The parameters are tested using Bayesian likelihood ratio formula in 40 same-speaker and 360 different-speaker pairs, including estimation of error rates, equal error rates and Overall Likelihood Ratio. One-way ANOVA is performed to determine whether inter-speaker variability is higher than intra- speaker variability across languages. The most successful discriminant is degree of hesitancy with ER of 42.5%/28%, (EER: 33%), followed by average pause duration with ER 35%/45.56%, (EER: 40%). Although the research features a closed-set comparison, which is not very common in forensic reality, the results are still relevant for forensic phoneticians working on criminal cases or as expert witnesses. This study pioneers in forensically comparing Serbian and English as well as in forensically testing temporal parameters on bilingual speakers. Further research should focus on comparing two stress-timed or two syllable-timed languages to test whether they will be more comparable in terms of temporal aspects of speech. Celem badania jest analiza możliwości identyfikacji mówcy kryminalistycznego i sądowego podczas zadawania pytań w różnych językach, z wykorzystaniem parametrów temporalnych. (wskaźnik artykulcji, wskaźnik mowy, stopień niezdecydowania, odsetek pauz, średnia czas trwania pauzy). Korpus obejmuje 10 mówców kobiet z Serbii, które znają język angielksi na poziomie zaawwansowanym. Patrametry są badane z wykorzystaniem beayesowskiego wzoru wskaźnika prawdopodobieństwa w 40 parach tcyh samych mówców i w 230 parach różnych mówców, z uwzględnieniem szacunku wskaźnika błędu, równiego wskaźnika błędu i Całościowego Wskaźnika Prawdopodobieństwa. badanie ma charakter pionierski w zakresie językoznawstwa sądowego i kryminalistycznego por1) ónawczego w parze jezyka serbskiego i angielskiego, podobnie, jak analiza parametrów temporalnych mówców bilingwalnych. Dalsze badania inny skoncentrować się na porównaniu języków z rytmem akcentowym i z rytmem sylabicznym.

Glottal-Source Spectral Biometry for Voice Characterization

The biometric signature derived from the estimation of the power spectral density singularities of a speaker’s glottal source is described in the present work. This consists in the collection of peak-trough profiles found in the spectral density, as related to the biomechanics of the vocal folds. Samples of parameter estimations from a set of 100 normophonic (pathology-free) speakers are produced. Mapping the set of speaker’s samples to a manifold defined by Principal Component Analysis and clustering them by k-means in terms of the most relevant principal components shows the separation of speakers by gender. This means that the proposed signature conveys relevant speaker’s metainformation, which may be useful in security and forensic applications for which contextual side information is considered relevant

A Hybrid Parameterization Technique for Speaker Identification

Classical parameterization techniques for Speaker Identification use the codification of the power spectral density of raw speech, not discriminating between articulatory features produced by vocal tract dynamics (acoustic-phonetics) from glottal source biometry. Through the present paper a study is conducted to separate voicing fragments of speech into vocal and glottal components, dominated respectively by the vocal tract transfer function estimated adaptively to track the acoustic-phonetic sequence of the message, and by the glottal characteristics of the speaker and the phonation gesture. The separation methodology is based in Joint Process Estimation under the un-correlation hypothesis between vocal and glottal spectral distributions. Its application on voiced speech is presented in the time and frequency domains. The parameterization methodology is also described. Speaker Identification experiments conducted on 245 speakers are shown comparing different parameterization strategies. The results confirm the better performance of decoupled parameterization compared against approaches based on plain speech parameterization

Doctrinal Issues in Evidence and Proof

The word evidence ordinarily means the statements, events, items, or sensory perceptions that suggest the existence or nonexistence of, or truth or falsity of, another fact. Thus, one may say, “hoofbeats are evidence a horse may be passing.” Proof is similar in meaning but may connote more certainty. Evidence can also mean the study of either (1) how people make such inferences (especially when conjoined with the word proof) or (2) how law regulates information admissibility in the judicial context. Evidence in the latter sense is the name of a standard law school course in common law countries and a subject that is on all American state examinations for admission to the bar. As a subject in law, then, evidence traditionally encompasses only the legal rules and regulations governing the admissibility of evidence, inference, and argument, on questions of fact, in civil and criminal judicial trials. Surprising for American lawyers, most civil law countries do not have a separate basic course on evidence but, rather, fold it into the introductory course on procedure