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End-to-end automated speech recognition using a character based small scale transformer architecture.

Dissertation (MEng(Electronic Engineering))--University of Pretoria, 2024.

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Other Authors: De Villiers, Pieter
Format: Thesis
Language:English
Published: University of Pretoria 2024
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access_status_str Open Access
author2 De Villiers, Pieter
author_browse De Villiers, Pieter
author_facet De Villiers, Pieter
collection Thesis
dc_rights_str_mv © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MEng(Electronic Engineering))--University of Pretoria, 2024.
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:39:46.144Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2024
publishDateRange 2024
publishDateSort 2024
publisher University of Pretoria
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spelling oai:repository.up.ac.za:2263/94605 End-to-end automated speech recognition using a character based small scale transformer architecture. De Villiers, Pieter alex.loubser@gmail.com De Freitas, Allan Loubser, Alexander UCTD Speech recognition transformer end-to-end character based connectionist temporal classification Dissertation (MEng(Electronic Engineering))--University of Pretoria, 2024. This study explores the feasibility of constructing a small-scale speech recognition system capable of competing with larger, modern automated speech recognition (ASR) systems in both performance and word error rate (WER). Our central hypothesis posits that a compact transformer-based ASR model can yield comparable results, specifically in terms of WER, to traditional ASR models while challenging contemporary ASR systems that boast significantly larger computational sizes. The aim is to extend ASR capabilities to under-resourced languages with limited corpora, catering to scenarios where practitioners face constraints in both data availability and computational resources. The model, comprising a compact convolutional neural network (CNN) and transformer architecture with 2.214 million parameters, challenges the conventional wisdom that large-scale transformer-based ASR systems are essential for achieving high accuracy. In comparison, contemporary ASR systems often deploy over 300 million parameters. Trained on a modest dataset of approximately 3000 hours—significantly less than the 50,000 hours used in larger systems—the proposed model leverages the Common Voice and LibriSpeech datasets. Evaluation on the LibriSpeech test-clean and test-other datasets produced character error rates (CERs) of 6.40% and 16.73% and WERs of 16.03% and 35.51% respectively. Comparisons with existing architectures showcase the efficiency of our model. A gated recurrent unit (GRU) architecture, albeit achieving lower error rates, incurred a computational cost 24 times larger than our proposed model. Large-scale transformer architectures, while achieving marginally lower WERs (2-4% on LibriSpeech test-clean), require 200 times more parameters and 53,000 additional hours of training data. Modern large language models are used to improve the WERs, but require large computational resources. To further enhance performance, a small 4-gram language model was integrated into our end-to-end ASR model, resulting in improved WERs. The overarching goal of this work is to provide a practical solution for practitioners dealing with limited datasets and computational resources, particularly in the context of under-resourced languages. MultiChoice Chair of Machine Learning Electrical, Electronic and Computer Engineering Masters of Engineering (Electronic Engineering) Unrestricted Faculty of Engineering, Built Environment and Information Technology SDG-09: Industry, innovation and infrastructure 2024-02-14T12:45:07Z 2024-02-14T12:45:07Z 2024-04-29 2024-02-12 Dissertation * April 2024 (A2024) http://hdl.handle.net/2263/94605 https://doi.org/10.25403/UPresearchdata.25217993 en © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Speech recognition
transformer
end-to-end
character based
connectionist temporal classification
End-to-end automated speech recognition using a character based small scale transformer architecture.
title End-to-end automated speech recognition using a character based small scale transformer architecture.
title_full End-to-end automated speech recognition using a character based small scale transformer architecture.
title_fullStr End-to-end automated speech recognition using a character based small scale transformer architecture.
title_full_unstemmed End-to-end automated speech recognition using a character based small scale transformer architecture.
title_short End-to-end automated speech recognition using a character based small scale transformer architecture.
title_sort end to end automated speech recognition using a character based small scale transformer architecture
topic UCTD
Speech recognition
transformer
end-to-end
character based
connectionist temporal classification
url http://hdl.handle.net/2263/94605
https://doi.org/10.25403/UPresearchdata.25217993