Thesis (M.Sc. (Computer Science)) -- University of Limpopo, 2015 / This study investigates the potential of using graphemes, instead of phonemes, as acoustic sub-word units for monolingual and cross-lingual speech recognition for some of the under-resourced languages of the Limpopo Province, namely, IsiNdebele, Sepedi and Tshivenda. The performance of a grapheme-based recognition system is compared to that of phoneme-based recognition system. For each selected under-resourced language, automatic speech recognition (ASR) system based on the use of hidden Markov models (HMMs) was developed using both graphemes and phonemes as acoustic sub-word units. The ASR framework used models emission distributions by 16 Gaussian Mixture Models (GMMs) with 2 mixture increments. A third-order n-gram language model was used in all experiments. Identical speech datasets were used for each experiment per language. The LWAZI speech corpora and the National Centre for Human Language Technologies (NCHLT) speech corpora were used for training and testing the tied-state context-dependent acoustic models. The performance of all systems was evaluated at the word-level recognition using word error rate (WER). The results of our study show that grapheme-based continuous speech recognition, which copes with the problem of low-quality or unavailable pronunciation dictionaries, is comparable to phoneme-based recognition for the selected under-resourced languages in both the monolingual and cross-lingual speech recognition tasks. The study significantly demonstrates that context-dependent grapheme-based sub-word units can be reliable for small and medium-large vocabulary speech recognition tasks for these languages. / Telkom SA

This dissertation suggests a new approach to reading instruction and phonetic control in materials development. The central feature of this approach is its reliance on phoneme-grapheme correspondence data. Specifically, the products of this dissertation were (1) the development of relative frequency tables depicting the various phonemes produced by a given grapheme structure, (2) the development of five different levels of phonetic sophistication, (3) the classification of 974 words as regular or irregular in accordance with each level of sophistication, and (4) the phonetic rewriting of three existing short stories to make them phonetically regular. One of the phonetically rewritten stories was given to an existing group of sixth grade students along with its original form. The students performed with superior reading speed and equal comprehension on the phonetically rewritten story. This difference was significant at the .01 level.

No description available.

Grapheme-color synesthesia, wherein achromatic graphemes are experienced as chromatic, presents insights into how the brain integrates subjective experiences. The neural correlates of grapheme-color synesthesia are highly debated, with the field full of inconsistent results. To compile the existing functional magnetic resonance imaging literature on grapheme-color synesthesia, the present thesis combined a systematic review with two coordinate-based Activation Likelihood Estimation meta-analyses. Two separate analyses were conducted to see whether investigating synesthesia through chromatic stimuli and incongruency effects would lead to the same activation patterns as investigating it through achromatic stimuli. Therefore, the main analysis included ten studies and more heterogeneity through chromatic stimuli, while the strict analysis had five studies but only achromatic stimuli and thus less heterogeneity. These analyses found convergent activation in the parietal lobe in the main analysis and the frontal lobe in the strict analysis. Although only limited interpretations of the results can be made, the present meta-analyses provided insights into the current state of research on grapheme-color synesthesia. Because the lack of comparability and methodological consensus in the field of synesthesia is evident, further research efforts are encouraged for the field to reach a state where truly convergent findings can be detected.

Färdigheten att avkoda ord är en grundläggande förutsättning för förmågan att läsa och har därmed en avgörande roll i elevers läsutveckling. Framgångsrik undervisning krävs för att eleverna ska ges möjlighet och förutsättningar att utveckla färdigheten att avkoda, det vill säga förståelse för sambandet mellan fonem och grafem. Med detta som utgångspunkt är syftet med studien att undersöka hur sju lärare i årskurs 1 beskriver att de utformar undervisningen i avkodning för att skapa förutsättningar för att eleverna ska utveckla färdigheten att avkoda ord. Studien utgår från en kvalitativ forskningsansats samt ett sociokulturellt perspektiv på lärande och utveckling. Empiriskt material har samlats in genom semi-strukturerade intervjuer där totalt sju lärare i årskurs 1 medverkade. Lärarna var slumpvis utvalda från olika skolor i två medelstora städer i Sverige. Resultatet visar att lärare använder olika medierande verktyg i form av digitala redskap, läromedel och aktiviteter i undervisningen, där samtalet och det sociala samspelet får stort utrymme. Det framkommer även att lärare använder sig själv som verktyg i avkodningsundervisningen där läraren stöttar, utmanar och fungerar som förebild för eleverna.  Vid utformandet av undervisningen framgår dessutom att forskning och beprövad erfarenhet samt elevers olika förutsättningar är någonting lärare förhåller sig till. Resultatet synliggör att undervisning kring avkodning varierar mellan olika lärare eftersom elevers individuella behov ligger till grund vid val av verktyg och vid utformningen av undervisningen. / Decoding skills are a crucial part of students reading development, since the ability to decode words is a fundamental qualification for reading. To give the pupils the opportunity to develop knowledge of phoneme-grapheme correspondences, an effective instruction is required. In light of this, the purpose of this paper is to examine how first grade teachers describe how they design instruction to create conditions for the students to develop decoding skills. The paper is based on a qualitative research approach and a socio-cultural perspective on learning and development. Through semi-structured interviews, empirical material has been collected from a total of seven participating first grade teachers. The teachers were randomly selected from different schools in two medium-sized cities in Sweden. The results show that teachers use mediating tools in form of digital gears, teaching materials and activities, where social interaction is emphasized. Teachers also function as tools, because they support, challenge and serve as role models for the pupils. Furthermore, the results reveal that research and proven experience as well as pupils’ different pre-conditions and needs affect teachers when they create decoding instruction. The results show that pupils’ individual needs are the starting point when teachers choose tools and create decoding instruction, which is why decoding instruction varies between different teachers.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis investigates various data-driven techniques by which pronunciation dictionaries can be automatically augmented. First, well-established grapheme-to-phoneme (G2P) conversion techniques are evaluated for Standard South African English (SSAE), British English (RP) and American English (GenAm) by means of four appropriate dictionaries: SAEDICT, BEEP, CMUDICT and PRONLEX. Next, the decision tree algorithm is extended to allow the conversion of pronunciations between different accents by means of phoneme-to-phoneme (P2P) and grapheme-andphoneme- to-phoneme (GP2P) conversion. P2P conversion uses the phonemes of the source accent as input to the decision trees. GP2P conversion further incorporates the graphemes into the decision tree input. Both P2P and GP2P conversion are evaluated using the four dictionaries. It is found that, when the pronunciation is needed for a word not present in the target accent, it is substantially more accurate to modify an existing pronunciation from a different accent, than to derive it from the word’s spelling using G2P conversion. When converting between accents, GP2P conversion provides a significant further increase in performance above P2P. Finally, experiments are performed to determine how large a training dictionary is required in a target accent for G2P, P2P and GP2P conversion. It is found that GP2P conversion requires less training data than P2P and substantially less than G2P conversion. Furthermore, it is found that very little training data is needed for GP2P to perform at almost maximum accuracy. The bulk of the accuracy is achieved within the initial 500 words, and after 3000 words there is almost no further improvement. Some specific approaches to compiling the best training set are also considered. By means of an iterative greedy algorithm an optimal ranking of words to be included in the training set is discovered. Using this set is shown to lead to substantially better GP2P performance for the same training set size in comparison with alternative approaches such as the use of phonetically rich words or random selections. A mere 25 words of training data from this optimal set already achieve an accuracy within 1% of that of the full training dictionary. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek verskeie data-gedrewe tegnieke waarmee uitspraakwoordeboeke outomaties aangevul kan word. Eerstens word gevestigde grafeem-na-foneem (G2P) omskakelingstegnieke ge¨evalueer vir Standaard Suid-Afrikaanse Engels (SSAE), Britse Engels (RP) en Amerikaanse Engels (GenAm) deur middel van vier geskikte woordeboeke: SAEDICT, BEEP, CMUDICT en PRONLEX. Voorts word die beslissingsboomalgoritme uitgebrei om die omskakeling van uitsprake tussen verskillende aksente moontlik te maak, deur middel van foneem-na-foneem (P2P) en grafeem-en-foneem-na-foneem (GP2P) omskakeling. P2P omskakeling gebruik die foneme van die bronaksent as inset vir die beslissingsbome. GP2P omskakeling inkorporeer verder die grafeme by die inset. Beide P2P en GP2P omskakeling word evalueer deur middel van die vier woordeboeke. Daar word bevind dat wanneer die uitspraak benodig word vir ’n woord wat nie in die teikenaksent teenwoordig is nie, dit bepaald meer akkuraat is om ’n bestaande uitspraak van ’n ander aksent aan te pas, as om dit af te lei vanuit die woord se spelling met G2P omskakeling. Wanneer daar tussen aksente omgeskakel word, gee GP2P omskakeling ’n verdere beduidende verbetering in akkuraatheid bo P2P. Laastens word eksperimente uitgevoer om die grootte te bepaal van die afrigtingswoordeboek wat benodig word in ’n teikenaksent vir G2P, P2P en GP2P omskakeling. Daar word bevind dat GP2P omskakeling minder afrigtingsdata as P2P en substansieel minder as G2P benodig. Verder word dit bevind dat baie min afrigtingsdata benodig word vir GP2P om teen bykans maksimum akkuraatheid te funksioneer. Die oorwig van die akkuraatheid word binne die eerste 500 woorde bereik, en n´a 3000 woorde is daar amper geen verdere verbetering nie. ’n Aantal spesifieke benaderings word ook oorweeg om die beste afrigtingstel saam te stel. Deur middel van ’n iteratiewe, gulsige algoritme word ’n optimale rangskikking van woorde bepaal vir insluiting by die afrigtingstel. Daar word getoon dat deur hierdie stel te gebruik, substansieel beter GP2P gedrag verkry word vir dieselfde grootte afrigtingstel in vergelyking met alternatiewe benaderings soos die gebruik van foneties-ryke woorde of lukrake seleksies. ’n Skamele 25 woorde uit hierdie optimale stel gee reeds ’n akkuraatheid binne 1% van di´e van die volle afrigtingswoordeboek.

No description available.

Text -to-speech systems currently are of great importance in the community. One core technology in this human language technology resource is stress assignment which plays an important role in any text-to-speech system. At present no automatic stress assigner for Afrikaans exists. For these reasons, the two most important aims of this project will be: a) to develop a complete and accurate set of stress rules for Afrikaans that can be implemented in an automatic stress assigner, and b) to develop an effective and highly accurate stress assigner in order to assign Afrikaans stress to words quickly and effectively. A set of stress rules for Afrikaans was developed in order to reach the first goal. It consists of 18 rules that are divided into groups for words that contain a schwa, derivations, and disyllabic, tri-syllabic and polysyllabic simplex words. Next, different approaches that can be used to develop a stress assigner were examined, and the rule-based approach was used to implement the developed stress rules within the stress assigner. The programming language, Perl, was chosen for the implementation of the rules. The chosen algorithm was used to generate a stress assigner for Afrikaans by implementing the stress rules developed. The hyphenator, Calomo and the compound analyser, CKarma was used to hyphenate all the test data and detect word boundaries within compounds. A dataset of 10 000 correctly annotated tokens was developed during the testing process. The evaluation of the stress assigner consists of four phases. During the first phase, the stress assigner was evaluated with the 10 000 tokens and achieved an accuracy of 92.09%. The grapheme - to-phoneme converter was evaluated with the same data and scored 91.9%. The influence of various factors on stress assignment was determined, and it was established that stress assignment is an essential component of rule-based grapheme-to-phoneme conversion. In conclusion, it can be said that the stress assigner achieved satisfactory results, and that the stress assigner can be successfully utilized in future projects to develop training data for further experiments with stress assignment and grapheme-to-phoneme conversion for Afrikaans. Experiments can be conducted in future with data-driven approaches that possibly may lead to better results in Afrikaans stress assignment and grapheme-to-phoneme conversion. / Thesis (M.A. (Applied Language and Literary Studies))--North-West University, Potchefstroom Campus, 2010.

Text -to-speech systems currently are of great importance in the community. One core technology in this human language technology resource is stress assignment which plays an important role in any text-to-speech system. At present no automatic stress assigner for Afrikaans exists. For these reasons, the two most important aims of this project will be: a) to develop a complete and accurate set of stress rules for Afrikaans that can be implemented in an automatic stress assigner, and b) to develop an effective and highly accurate stress assigner in order to assign Afrikaans stress to words quickly and effectively. A set of stress rules for Afrikaans was developed in order to reach the first goal. It consists of 18 rules that are divided into groups for words that contain a schwa, derivations, and disyllabic, tri-syllabic and polysyllabic simplex words. Next, different approaches that can be used to develop a stress assigner were examined, and the rule-based approach was used to implement the developed stress rules within the stress assigner. The programming language, Perl, was chosen for the implementation of the rules. The chosen algorithm was used to generate a stress assigner for Afrikaans by implementing the stress rules developed. The hyphenator, Calomo and the compound analyser, CKarma was used to hyphenate all the test data and detect word boundaries within compounds. A dataset of 10 000 correctly annotated tokens was developed during the testing process. The evaluation of the stress assigner consists of four phases. During the first phase, the stress assigner was evaluated with the 10 000 tokens and achieved an accuracy of 92.09%. The grapheme - to-phoneme converter was evaluated with the same data and scored 91.9%. The influence of various factors on stress assignment was determined, and it was established that stress assignment is an essential component of rule-based grapheme-to-phoneme conversion. In conclusion, it can be said that the stress assigner achieved satisfactory results, and that the stress assigner can be successfully utilized in future projects to develop training data for further experiments with stress assignment and grapheme-to-phoneme conversion for Afrikaans. Experiments can be conducted in future with data-driven approaches that possibly may lead to better results in Afrikaans stress assignment and grapheme-to-phoneme conversion. / Thesis (M.A. (Applied Language and Literary Studies))--North-West University, Potchefstroom Campus, 2010.

In this study, I deal with general laws or principles of Czech orthography. After the introduction, I define the smallest written unit, a grapheme in the second chapter. In the third and fourth chapters, I focus on how and where two main principles of Czech orthography manifest, and how and where they are violated. The first of these principles is the phonemic principle, ie. the principle of a one-to-one correspondence between a phoneme and a grapheme, and the second one is the morphemic principle, ie. the principle of a one-to-one correspondence between a morpheme and its written form.