2,601 research outputs found
Exploiting Contextual Information for Prosodic Event Detection Using Auto-Context
Prosody and prosodic boundaries carry significant information regarding linguistics and paralinguistics and are important aspects of speech. In the field of prosodic event detection, many local acoustic features have been investigated; however, contextual information has not yet been thoroughly exploited. The most difficult aspect of this lies in learning the long-distance contextual dependencies effectively and efficiently. To address this problem, we introduce the use of an algorithm called auto-context. In this algorithm, a classifier is first trained based on a set of local acoustic features, after which the generated probabilities are used along with the local features as contextual information to train new classifiers. By iteratively using updated probabilities as the contextual information, the algorithm can accurately model contextual dependencies and improve classification ability. The advantages of this method include its flexible structure and the ability of capturing contextual relationships. When using the auto-context algorithm based on support vector machine, we can improve the detection accuracy by about 3% and F-score by more than 7% on both two-way and four-way pitch accent detections in combination with the acoustic context. For boundary detection, the accuracy improvement is about 1% and the F-score improvement reaches 12%. The new algorithm outperforms conditional random fields, especially on boundary detection in terms of F-score. It also outperforms an n-gram language model on the task of pitch accent detection
Spoken Language Intent Detection using Confusion2Vec
Decoding speaker's intent is a crucial part of spoken language understanding
(SLU). The presence of noise or errors in the text transcriptions, in real life
scenarios make the task more challenging. In this paper, we address the spoken
language intent detection under noisy conditions imposed by automatic speech
recognition (ASR) systems. We propose to employ confusion2vec word feature
representation to compensate for the errors made by ASR and to increase the
robustness of the SLU system. The confusion2vec, motivated from human speech
production and perception, models acoustic relationships between words in
addition to the semantic and syntactic relations of words in human language. We
hypothesize that ASR often makes errors relating to acoustically similar words,
and the confusion2vec with inherent model of acoustic relationships between
words is able to compensate for the errors. We demonstrate through experiments
on the ATIS benchmark dataset, the robustness of the proposed model to achieve
state-of-the-art results under noisy ASR conditions. Our system reduces
classification error rate (CER) by 20.84% and improves robustness by 37.48%
(lower CER degradation) relative to the previous state-of-the-art going from
clean to noisy transcripts. Improvements are also demonstrated when training
the intent detection models on noisy transcripts
The role of beat gesture and pitch accent in semantic processing : An ERP study
Peer reviewedPublisher PD
Rapid neural processing of grammatical tone in second language learners
The present dissertation investigates how beginner learners process grammatical tone in a second language and whether their processing is influenced by phonological transfer. Paper I focuses on the acquisition of Swedish grammatical tone by beginner learners from a non-tonal language, German. Results show that non-tonal beginner learners do not process the grammatical regularities of the tones but rather treat them akin to piano tones. A rightwards-going spread of activity in response to pitch difference in Swedish tones possibly indicates a process of tone sensitisation. Papers II to IV investigate how artificial grammatical tone, taught in a word-picture association paradigm, is acquired by German and Swedish learners. The results of paper II show that interspersed mismatches between grammatical tone and picture referents evoke an N400 only for the Swedish learners. Both learner groups produce N400 responses to picture mismatches related to grammatically meaningful vowel changes. While mismatch detection quickly reaches high accuracy rates, tone mismatches are least accurately and most slowly detected in both learner groups. For processing of the grammatical L2 words outside of mismatch contexts, the results of paper III reveal early, preconscious and late, conscious processing in the Swedish learner group within 20 minutes of acquisition (word recognition component, ELAN, LAN, P600). German learners only produce late responses: a P600 within 20 minutes and a LAN after sleep consolidation. The surprisingly rapid emergence of early grammatical ERP components (ELAN, LAN) is attributed to less resource-heavy processing outside of violation contexts. Results of paper IV, finally, indicate that memory trace formation, as visible in the word recognition component at ~50 ms, is only possible at the highest level of formal and functional similarity, that is, for words with falling tone in Swedish participants. Together, the findings emphasise the importance of phonological transfer in the initial stages of second language acquisition and suggest that the earlier the processing, the more important the impact of phonological transfer
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Deep Learning for Automatic Assessment and Feedback of Spoken English
Growing global demand for learning a second language (L2), particularly English, has led to
considerable interest in automatic spoken language assessment, whether for use in computerassisted language learning (CALL) tools or for grading candidates for formal qualifications.
This thesis presents research conducted into the automatic assessment of spontaneous nonnative English speech, with a view to be able to provide meaningful feedback to learners. One
of the challenges in automatic spoken language assessment is giving candidates feedback on
particular aspects, or views, of their spoken language proficiency, in addition to the overall
holistic score normally provided. Another is detecting pronunciation and other types of errors
at the word or utterance level and feeding them back to the learner in a useful way.
It is usually difficult to obtain accurate training data with separate scores for different
views and, as examiners are often trained to give holistic grades, single-view scores can
suffer issues of consistency. Conversely, holistic scores are available for various standard
assessment tasks such as Linguaskill. An investigation is thus conducted into whether
assessment scores linked to particular views of the speaker’s ability can be obtained from
systems trained using only holistic scores.
End-to-end neural systems are designed with structures and forms of input tuned to single
views, specifically each of pronunciation, rhythm, intonation and text. By training each
system on large quantities of candidate data, individual-view information should be possible
to extract. The relationships between the predictions of each system are evaluated to examine
whether they are, in fact, extracting different information about the speaker. Three methods
of combining the systems to predict holistic score are investigated, namely averaging their
predictions and concatenating and attending over their intermediate representations. The
combined graders are compared to each other and to baseline approaches.
The tasks of error detection and error tendency diagnosis become particularly challenging
when the speech in question is spontaneous and particularly given the challenges posed by
the inconsistency of human annotation of pronunciation errors. An approach to these tasks is
presented by distinguishing between lexical errors, wherein the speaker does not know how a
particular word is pronounced, and accent errors, wherein the candidate’s speech exhibits
consistent patterns of phone substitution, deletion and insertion. Three annotated corpora
x
of non-native English speech by speakers of multiple L1s are analysed, the consistency of
human annotation investigated and a method presented for detecting individual accent and
lexical errors and diagnosing accent error tendencies at the speaker level
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