Speech synthesis and quality evaluation

The objective of this dissertation is to compare the results of objective Speech Quality Assessment (SQA) between human and synthetic speeches to verify the feasibility of using this method to identify if a speech is human-recorded. We also tried using speech synthesis and SQA to quantify the perfor...

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Main Author: Jiang, Xiaotong
Other Authors: Tan Yap Peng
Format: Thesis-Master by Coursework
Language:English
Published: Nanyang Technological University 2024
Subjects:
Online Access:https://hdl.handle.net/10356/181485
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author Jiang, Xiaotong
author2 Tan Yap Peng
author_facet Tan Yap Peng
Jiang, Xiaotong
author_sort Jiang, Xiaotong
collection NTU
description The objective of this dissertation is to compare the results of objective Speech Quality Assessment (SQA) between human and synthetic speeches to verify the feasibility of using this method to identify if a speech is human-recorded. We also tried using speech synthesis and SQA to quantify the performance of a speech recognition task without original transcript. Human speech samples were taken from LibriSpeech, VCC 2018, and AISHELL-3, while synthetic speeches were generated by synthesizers called VITS, ChatTTS, and Tacotron 2. Preprocessing involved standardizing sampling rates and bit depths, followed by transcription with WhisperX to calculate Word Error Rate (WER) and Character Error Rate (CER). MOSNet, an SQA system was implemented to score speech quality, with results showing that MOSNet can accurately identify human speech within its training set but struggles with generalization outside it. Despite some correlation between MOSNet predictions and WERs, the results suggest that MOSNet alone cannot reliably assess speech recognition quality. The dissertation also conducted a subjective SQA test with 14 participants to compare human estimations with MOSNet evaluations, revealing challenges in distinguishing natural human speech from synthetic counterparts, and underscoring the importance of factors such as authentic accents and natural delivery in speech evaluations.
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spelling ntu-10356/1814852024-12-06T15:49:16Z Speech synthesis and quality evaluation Jiang, Xiaotong Tan Yap Peng School of Electrical and Electronic Engineering EYPTan@ntu.edu.sg Computer and Information Science Engineering Speech quality assessment (SQA) MOSNet Human speech Synthetic speech WhisperX Word error rate (WER) Character error rate (CER) Speech synthesis Speech recognition The objective of this dissertation is to compare the results of objective Speech Quality Assessment (SQA) between human and synthetic speeches to verify the feasibility of using this method to identify if a speech is human-recorded. We also tried using speech synthesis and SQA to quantify the performance of a speech recognition task without original transcript. Human speech samples were taken from LibriSpeech, VCC 2018, and AISHELL-3, while synthetic speeches were generated by synthesizers called VITS, ChatTTS, and Tacotron 2. Preprocessing involved standardizing sampling rates and bit depths, followed by transcription with WhisperX to calculate Word Error Rate (WER) and Character Error Rate (CER). MOSNet, an SQA system was implemented to score speech quality, with results showing that MOSNet can accurately identify human speech within its training set but struggles with generalization outside it. Despite some correlation between MOSNet predictions and WERs, the results suggest that MOSNet alone cannot reliably assess speech recognition quality. The dissertation also conducted a subjective SQA test with 14 participants to compare human estimations with MOSNet evaluations, revealing challenges in distinguishing natural human speech from synthetic counterparts, and underscoring the importance of factors such as authentic accents and natural delivery in speech evaluations. Master's degree 2024-12-04T05:38:32Z 2024-12-04T05:38:32Z 2024 Thesis-Master by Coursework Jiang, X. (2024). Speech synthesis and quality evaluation. Master's thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/181485 https://hdl.handle.net/10356/181485 en application/pdf Nanyang Technological University
spellingShingle Computer and Information Science
Engineering
Speech quality assessment (SQA)
MOSNet
Human speech
Synthetic speech
WhisperX
Word error rate (WER)
Character error rate (CER)
Speech synthesis
Speech recognition
Jiang, Xiaotong
Speech synthesis and quality evaluation
title Speech synthesis and quality evaluation
title_full Speech synthesis and quality evaluation
title_fullStr Speech synthesis and quality evaluation
title_full_unstemmed Speech synthesis and quality evaluation
title_short Speech synthesis and quality evaluation
title_sort speech synthesis and quality evaluation
topic Computer and Information Science
Engineering
Speech quality assessment (SQA)
MOSNet
Human speech
Synthetic speech
WhisperX
Word error rate (WER)
Character error rate (CER)
Speech synthesis
Speech recognition
url https://hdl.handle.net/10356/181485
work_keys_str_mv AT jiangxiaotong speechsynthesisandqualityevaluation