52 research outputs found
PHONOTACTIC AND ACOUSTIC LANGUAGE RECOGNITION
Práce pojednává o fonotaktickĂ©m a akustickĂ©m pĹ™Ăstupu pro automatickĂ© rozpoznávánĂ jazyka. Prvnà část práce pojednává o fonotaktickĂ©m pĹ™Ăstupu zaloĹľenĂ©m na vĂ˝skytu fonĂ©movĂ˝ch sekvenci v Ĺ™eÄŤi. NejdĹ™Ăve je prezentován popis vĂ˝voje fonĂ©movĂ©ho rozpoznávaÄŤe jako techniky pro pĹ™epis Ĺ™eÄŤi do sekvence smysluplnĂ˝ch symbolĹŻ. HlavnĂ dĹŻraz je kladen na dobrĂ© natrĂ©novánĂ fonĂ©movĂ©ho rozpoznávaÄŤe a kombinaci vĂ˝sledkĹŻ z nÄ›kolika fonĂ©movĂ˝ch rozpoznávaÄŤĹŻ trĂ©novanĂ˝ch na rĹŻznĂ˝ch jazycĂch (ParalelnĂ fonĂ©movĂ© rozpoznávánĂ následovanĂ© jazykovĂ˝mi modely (PPRLM)). Práce takĂ© pojednává o novĂ© technice anti-modely v PPRLM a studuje pouĹľitĂ fonĂ©movĂ˝ch grafĹŻ mĂsto nejlepšĂho pĹ™episu. Na závÄ›r práce jsou porovnány dva pĹ™Ăstupy modelovánĂ vĂ˝stupu fonĂ©movĂ©ho rozpoznávaÄŤe -- standardnĂ n-gramovĂ© jazykovĂ© modely a binárnĂ rozhodovacĂ stromy. HlavnĂ pĹ™Ănos v akustickĂ©m pĹ™Ăstupu je diskriminativnĂ modelovánĂ cĂlovĂ˝ch modelĹŻ jazykĹŻ a prvnĂ experimenty s kombinacĂ diskriminativnĂho trĂ©novánĂ a na pĹ™ĂznacĂch, kde byl odstranÄ›n vliv kanálu. Práce dále zkoumá rĹŻznĂ© druhy technik fĂşzi akustickĂ©ho a fonotaktickĂ©ho pĹ™Ăstupu. Všechny experimenty jsou provedeny na standardnĂch datech z NIST evaluaci konanĂ© v letech 2003, 2005 a 2007, takĹľe jsou pĹ™Ămo porovnatelnĂ© s vĂ˝sledky ostatnĂch skupin zabĂ˝vajĂcĂch se automatickĂ˝m rozpoznávánĂm jazyka. S fĂşzĂ uvedenĂ˝ch technik jsme posunuli state-of-the-art vĂ˝sledky a dosáhli vynikajĂcĂch vĂ˝sledkĹŻ ve dvou NIST evaluacĂch.This thesis deals with phonotactic and acoustic techniques for automatic language recognition (LRE). The first part of the thesis deals with the phonotactic language recognition based on co-occurrences of phone sequences in speech. A thorough study of phone recognition as tokenization technique for LRE is done, with focus on the amounts of training data for phone recognizer and on the combination of phone recognizers trained on several language (Parallel Phone Recognition followed by Language Model - PPRLM). The thesis also deals with novel technique of anti-models in PPRLM and investigates into using phone lattices instead of strings. The work on phonotactic approach is concluded by a comparison of classical n-gram modeling techniques and binary decision trees. The acoustic LRE was addressed too, with the main focus on discriminative techniques for training target language acoustic models and on initial (but successful) experiments with removing channel dependencies. We have also investigated into the fusion of phonotactic and acoustic approaches. All experiments were performed on standard data from NIST 2003, 2005 and 2007 evaluations so that the results are directly comparable to other laboratories in the LRE community. With the above mentioned techniques, the fused systems defined the state-of-the-art in the LRE field and reached excellent results in NIST evaluations.
Acoustic Modelling for Under-Resourced Languages
Automatic speech recognition systems have so far been developed only for very few languages out of the 4,000-7,000 existing ones.
In this thesis we examine methods to rapidly create acoustic models in new, possibly under-resourced languages, in a time and cost effective manner. For this we examine the use of multilingual models, the application of articulatory features across languages, and the automatic discovery of word-like units in unwritten languages
Automatic Speech Recognition for Low-resource Languages and Accents Using Multilingual and Crosslingual Information
This thesis explores methods to rapidly bootstrap automatic speech recognition systems for languages, which lack resources for speech and language processing. We focus on finding approaches which allow using data from multiple languages to improve the performance for those languages on different levels, such as feature extraction, acoustic modeling and language modeling. Under application aspects, this thesis also includes research work on non-native and Code-Switching speech
Cloud-based Automatic Speech Recognition Systems for Southeast Asian Languages
This paper provides an overall introduction of our Automatic Speech
Recognition (ASR) systems for Southeast Asian languages. As not much existing
work has been carried out on such regional languages, a few difficulties should
be addressed before building the systems: limitation on speech and text
resources, lack of linguistic knowledge, etc. This work takes Bahasa Indonesia
and Thai as examples to illustrate the strategies of collecting various
resources required for building ASR systems.Comment: Published by the 2017 IEEE International Conference on Orange
Technologies (ICOT 2017
How Phonotactics Affect Multilingual and Zero-shot ASR Performance
The idea of combining multiple languages' recordings to train a single
automatic speech recognition (ASR) model brings the promise of the emergence of
universal speech representation. Recently, a Transformer encoder-decoder model
has been shown to leverage multilingual data well in IPA transcriptions of
languages presented during training. However, the representations it learned
were not successful in zero-shot transfer to unseen languages. Because that
model lacks an explicit factorization of the acoustic model (AM) and language
model (LM), it is unclear to what degree the performance suffered from
differences in pronunciation or the mismatch in phonotactics. To gain more
insight into the factors limiting zero-shot ASR transfer, we replace the
encoder-decoder with a hybrid ASR system consisting of a separate AM and LM.
Then, we perform an extensive evaluation of monolingual, multilingual, and
crosslingual (zero-shot) acoustic and language models on a set of 13
phonetically diverse languages. We show that the gain from modeling
crosslingual phonotactics is limited, and imposing a too strong model can hurt
the zero-shot transfer. Furthermore, we find that a multilingual LM hurts a
multilingual ASR system's performance, and retaining only the target language's
phonotactic data in LM training is preferable.Comment: Accepted for publication in IEEE ICASSP 2021. The first 2 authors
contributed equally to this wor
SQuId: Measuring Speech Naturalness in Many Languages
Much of text-to-speech research relies on human evaluation, which incurs
heavy costs and slows down the development process. The problem is particularly
acute in heavily multilingual applications, where recruiting and polling judges
can take weeks. We introduce SQuId (Speech Quality Identification), a
multilingual naturalness prediction model trained on over a million ratings and
tested in 65 locales-the largest effort of this type to date. The main insight
is that training one model on many locales consistently outperforms mono-locale
baselines. We present our task, the model, and show that it outperforms a
competitive baseline based on w2v-BERT and VoiceMOS by 50.0%. We then
demonstrate the effectiveness of cross-locale transfer during fine-tuning and
highlight its effect on zero-shot locales, i.e., locales for which there is no
fine-tuning data. Through a series of analyses, we highlight the role of
non-linguistic effects such as sound artifacts in cross-locale transfer.
Finally, we present the effect of our design decision, e.g., model size,
pre-training diversity, and language rebalancing with several ablation
experiments.Comment: Accepted at ICASSP 2023, with additional material in the appendi
Modularity and Neural Integration in Large-Vocabulary Continuous Speech Recognition
This Thesis tackles the problems of modularity in Large-Vocabulary Continuous Speech Recognition with use of Neural Network
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