published_or_final_version / Education / Doctoral / Doctor of Philosophy

This literature review sets out to revisit the studies exploring impact of rater characteristics on language oral assessments. Three categories of raters' backgrounds: occupation, accent familiarity, and native language are identified and will be addressed respectively in the following sections. The results showed that no consensus regarding raters' occupational background, linguistic background and native-speaker status on examiners' rating has been found so far. However, this review will highlight the current testing situations, bring up limitations from previous studies, provide implications for both teachers and raters, and hopefully shed light on future research. / text

<p>In this work, speaker characteristic modeling has been applied in the fields of automatic speech recognition (ASR) and automatic speaker verification (ASV). In ASR, a key problem is that acoustic mismatch between training and test conditions degrade classification per- formance. In this work, a child exemplifies a speaker not represented in training data and methods to reduce the spectral mismatch are devised and evaluated. To reduce the acoustic mismatch, predictive modeling based on spectral speech transformation is applied. Follow- ing this approach, a model suitable for a target speaker, not well represented in the training data, is estimated and synthesized by applying vocal tract predictive modeling (VTPM). In this thesis, the traditional static modeling on the utterance level is extended to dynamic modeling. This is accomplished by operating also on sub-utterance units, such as phonemes, phone-realizations, sub-phone realizations and sound frames.</p><p>Initial experiments shows that adaptation of an acoustic model trained on adult speech significantly reduced the word error rate of ASR for children, but not to the level of a model trained on children’s speech. Multi-speaker-group training provided an acoustic model that performed recognition for both adults and children within the same model at almost the same accuracy as speaker-group dedicated models, with no added model complexity. In the analysis of the cause of errors, body height of the child was shown to be correlated to word error rate.</p><p>A further result is that the computationally demanding iterative recognition process in standard VTLN can be replaced by synthetically extending the vocal tract length distribution in the training data. A multi-warp model is trained on the extended data and recognition is performed in a single pass. The accuracy is similar to that of the standard technique.</p><p>A concluding experiment in ASR shows that the word error rate can be reduced by ex- tending a static vocal tract length compensation parameter into a temporal parameter track. A key component to reach this improvement was provided by a novel joint two-level opti- mization process. In the process, the track was determined as a composition of a static and a dynamic component, which were simultaneously optimized on the utterance and sub- utterance level respectively. This had the principal advantage of limiting the modulation am- plitude of the track to what is realistic for an individual speaker. The recognition error rate was reduced by 10% relative compared with that of a standard utterance-specific estimation technique.</p><p>The techniques devised and evaluated can also be applied to other speaker characteristic properties, which exhibit a dynamic nature.</p><p>An excursion into ASV led to the proposal of a statistical speaker population model. The model represents an alternative approach for determining the reject/accept threshold in an ASV system instead of the commonly used direct estimation on a set of client and impos- tor utterances. This is especially valuable in applications where a low false reject or false ac- cept rate is required. In these cases, the number of errors is often too few to estimate a reli- able threshold using the direct method. The results are encouraging but need to be verified on a larger database.</p> / Pf-Star / KOBRA

The field of heritage language maintenance lacks an in-depth look at the social networks that make-up the linguistic interaction of heritage speakers of Spanish. Moreover, the social network studies that have focused on language maintenance have all investigated the maintenance of a first language spoken by immigrants or the use of a dialect. Undoubtedly, there is a lacuna of research with regard to heritage speakers of a language, which is the focus of the proposed study. There is an even greater deficit in the study of linguistic insecurity among heritage language speakers and the correlation that there may be with regard to social networks. The present research fills this gap by examining these issues within a population of heritage speakers of Spanish at the University of Arizona.This study examines correlations between linguistic insecurity, social networks and language use in heritage speakers of Spanish. The population investigated are college aged students registered in the beginning and intermediate courses of the Heritage Language Program at the University of Arizona, Tucson (SPAN 103, 203, and 253). Linguistic insecurity is measured using an adapted version of the Foreign Language Classroom Anxiety Scale (Horwitz, Horwitz, and Cope, 1986) and language use is measured through an online questionnaire. The subjects' social networks are identified using an adapted on-line version of the Cochran, Larner, Riley, Gunnarson, & Henderson's (1990) social network questionnaire. This study details the social networks of heritage language speakers of Spanish and presents the correlation between these networks, the participants' use of Spanish and their linguistic insecurity in a discussion regarding the speakers' prospects of maintaining the heritage language. Secondly, it presents correlations between the linguistic insecurity of heritage language speakers of Spanish, Spanish language use, oral proficiency and social network structure. The information provided by this study will help in the understanding of the function of social networks in the maintenance of a heritage language. It will further assist in the understanding of linguistic insecurity and provide a foundation for further research into how to address linguistic insecurity in the heritage language classroom.

The diploma thesis Czech Language of Native Speakers of Russian is a study which analyses the use of the Czech language by few non-native speakers whose native language is Russian. The first theoretical section constists of introduction to the most important theories in the field of language acquisition and selected types of analyses which will be used in my own research. The second part contains specification of my goals, approaches and the description of used materials. Third, there are language biographies of my speakers and analysis of several texts (or transcripts of oral recordings) with the emphasis on the influence of speaker's L1. The analysis of data is the accuracy, complexity and fluency measuring that should test qualities of speaker's language use from various points of view. The conclusion summarizes the results of the research and verification of my hypothesis. Key words: non-native speaker, Russian, Czech as foreign language, language error, fluency, accuracy, complexity

Tato práce hledá souvislost mezi intonačním rozpětím a přívětivostí, která je podle Pětifaktorového modelu považována za jednu ze složek osobnosti. Jelikož zkoumání projevů osobnostních rysů v hlase není ve fonetickém výzkumu příliš běžné, je v teoretické části popsán sou- časný stav poznání v oblasti postojů, popisu osobnosti a prvních do- jmů v hodnocení osobnosti. Představeny jsou především studie, které se týkají působení řeči. Jádrem práce je experiment, v němž je porov- náván vliv tří úrovní intonačního rozpětí (komprimovaná, normální a expandovaná) na hodnocení přívětivosti u 15 českých mluvčí. Per- cepčního testu se účastnilo 41 respondentů Intonačnímu rozpětí je věnována samostatná kapitola, která se zaměřuje především na pro- blematická místa popisu. Statistická analýza neprokázala významné rozdíly mezi úrovněmi rozpětí, podrobnější rozbor se tak zaměřil na odhalení rušivých proměnných a popis slabších trendů. Klíčová slova: intonační rozpětí, melodie řeči, vnímání mluvčího, stereo- typní hodnocení Abstract The purpose of the current study is to establish the relationship be- tween pitch range and agreeableness which is viewed as one of the personality traits according to the Big Five model. As the focus on the manifestation of personality traits in speech is not very common in phonetic...

This thesis pursues the topic of downtrends in Czech intonation in correlation with the geographical origin of speakers. The theoretical part is devoted to the section on the suprasegmental plateaux of the language - the intonation, the intonation variability, and mainly the intonation downtrends. It also brings a selective dialectical description of three Czech regions, which this thesis deals with: Plzeňsko, Štítecko and Břeclavsko. The practical part is targeted to the intonational analysis of the speech material (74 speakers overall), acquired in the previously mentioned regions. The average caliber of the guidelines, acquired by the application of the regressive line, were − for the given groups of speakers − compared and annotated, considering the age and sex of the respondents, (ideal) number of tacts or relative presence of the finding questions. key words: intonation, intonational downtrends, region, speaker, regressive line

While handling the task of speaker identification, forensic phoneticians use a combination of various parameters contained in different levels of speech signal. The main aim of the present thesis is to explore whether glottalization in Czech may be considered as a potentially useful parameter in this sense. In our research, we focus on the rate of prevocalic glottalization at word boundaries and we distinguish between different realisations of glottalization: canonical glottal stop and its hypoarticulated form - creaky voice. The studied material consists of repeated recordings of three male and four female speakers and contains both read text and spontaneous speech. The results do not indicate that the same speaker would use glottalization differently in the first and second recording, but a difference in glottalization is found between speakers. From the forensic phonetics point of view, this finding seems to be useful. Marginally, some other factors which are not directly connected with the speaker (height of following vowel, lexical factors and speech rate) were examined, but no influence on glottalization was found. Keywords: glottal stop, glottalization, forensic phonetics, speaker identification

The purpose of the present thesis is to shed light on the role of pauses in simultaneous interpreting between French and Czech, mainly from the point of view of the listeners of the source speeches in French as well as both students of interpretation and professional interpreters and from the viewpoint of the listeners of the speeches interpreted into Czech. It is divided into a theoretical and an empirical part. The theoretical part briefly outlines the process of simultaneous interpreting and Daniel Gile's Effort Model and then it focuses on prosody and individual prosodic (suprasegmental) features, especially pauses and their use in simultaneous interpreting. The empirical part describes the experiment and presents its results. The experiment itself examines the effect that unnaturally long or unnaturally placed pauses in the speaker's quasi-authentic source speeches have on the choice of strategy and the simultaneous interpreters' performances (students and professionnals) and on the subsequent assessment of their performances made by the listeners of the interpreted speeches. Keywords simultaneous interpreting, pause, listener, speech, speaker, interpreter, comprehensibility

(in English): Voice disguise can potentially occur in every utterance that is associated with any criminal case. In order to identify the perpetrator it is necessary to analyze the speech and understand how the different types of voice disguise can affect the speaker's voice qualities. This thesis focuses on the ability of voice disguise, portraying three groups of speakers in relation to their educational background. The aim of this work is to determine the strategies adopted by the speaker to conceal his/her identity and furthermore it poses the question whether differences among the three groups of speakers, their choice of strategy and its inherent success can be found. The basis for this research stems from 86 recordings which were undertaken in Pilsen and Prague with 43 young people aged 20 to 31. Two read utterances, one undisguised and the other freely disguised, were obtained from each of the participants and were compared with each other. The results show that the preferred forms of voice disguise appeared to involve changes in phonation - especially decrease or increase of fundamental frequency of the speaker's voice. Among the three groups of speakers, their choice and the success of the chosen strategy only minor differences could be found, yet for a final confirmation of this...