229 research outputs found
Scaling and Bias Codes for Modeling Speaker-Adaptive DNN-based Speech Synthesis Systems
Most neural-network based speaker-adaptive acoustic models for speech
synthesis can be categorized into either layer-based or input-code approaches.
Although both approaches have their own pros and cons, most existing works on
speaker adaptation focus on improving one or the other. In this paper, after we
first systematically overview the common principles of neural-network based
speaker-adaptive models, we show that these approaches can be represented in a
unified framework and can be generalized further. More specifically, we
introduce the use of scaling and bias codes as generalized means for
speaker-adaptive transformation. By utilizing these codes, we can create a more
efficient factorized speaker-adaptive model and capture advantages of both
approaches while reducing their disadvantages. The experiments show that the
proposed method can improve the performance of speaker adaptation compared with
speaker adaptation based on the conventional input code.Comment: Accepted for 2018 IEEE Workshop on Spoken Language Technology (SLT),
Athens, Greec
Reimagining Speech: A Scoping Review of Deep Learning-Powered Voice Conversion
Research on deep learning-powered voice conversion (VC) in speech-to-speech
scenarios is getting increasingly popular. Although many of the works in the
field of voice conversion share a common global pipeline, there is a
considerable diversity in the underlying structures, methods, and neural
sub-blocks used across research efforts. Thus, obtaining a comprehensive
understanding of the reasons behind the choice of the different methods in the
voice conversion pipeline can be challenging, and the actual hurdles in the
proposed solutions are often unclear. To shed light on these aspects, this
paper presents a scoping review that explores the use of deep learning in
speech analysis, synthesis, and disentangled speech representation learning
within modern voice conversion systems. We screened 621 publications from more
than 38 different venues between the years 2017 and 2023, followed by an
in-depth review of a final database consisting of 123 eligible studies. Based
on the review, we summarise the most frequently used approaches to voice
conversion based on deep learning and highlight common pitfalls within the
community. Lastly, we condense the knowledge gathered, identify main challenges
and provide recommendations for future research directions
Normal-to-Lombard Adaptation of Speech Synthesis Using Long Short-Term Memory Recurrent Neural Networks
In this article, three adaptation methods are compared based on how well they change the speaking style of a neural network based text-to-speech (TTS) voice. The speaking style conversion adopted here is from normal to Lombard speech. The selected adaptation methods are: auxiliary features (AF), learning hidden unit contribution (LHUC), and fine-tuning (FT). Furthermore, four state-of-the-art TTS vocoders are compared in the same context. The evaluated vocoders are: GlottHMM, GlottDNN, STRAIGHT, and pulse model in log-domain (PML). Objective and subjective evaluations were conducted to study the performance of both the adaptation methods and the vocoders. In the subjective evaluations, speaking style similarity and speech intelligibility were assessed. In addition to acoustic model adaptation, phoneme durations were also adapted from normal to Lombard with the FT adaptation method. In objective evaluations and speaking style similarity tests, we found that the FT method outperformed the other two adaptation methods. In speech intelligibility tests, we found that there were no significant differences between vocoders although the PML vocoder showed slightly better performance compared to the three other vocoders.Peer reviewe
Adaptation Algorithms for Neural Network-Based Speech Recognition: An Overview
We present a structured overview of adaptation algorithms for neural
network-based speech recognition, considering both hybrid hidden Markov model /
neural network systems and end-to-end neural network systems, with a focus on
speaker adaptation, domain adaptation, and accent adaptation. The overview
characterizes adaptation algorithms as based on embeddings, model parameter
adaptation, or data augmentation. We present a meta-analysis of the performance
of speech recognition adaptation algorithms, based on relative error rate
reductions as reported in the literature.Comment: Submitted to IEEE Open Journal of Signal Processing. 30 pages, 27
figure
Dysarthric Speech Recognition and Offline Handwriting Recognition using Deep Neural Networks
Millions of people around the world are diagnosed with neurological disorders like Parkinsonâs, Cerebral Palsy or Amyotrophic Lateral Sclerosis. Due to the neurological damage as the disease progresses, the person suffering from the disease loses control of muscles, along with speech deterioration. Speech deterioration is due to neuro motor condition that limits manipulation of the articulators of the vocal tract, the condition collectively called as dysarthria. Even though dysarthric speech is grammatically and syntactically correct, it is difficult for humans to understand and for Automatic Speech Recognition (ASR) systems to decipher. With the emergence of deep learning, speech recognition systems have improved a lot compared to traditional speech recognition systems, which use sophisticated preprocessing techniques to extract speech features.
In this digital era there are still many documents that are handwritten many of which need to be digitized. Offline handwriting recognition involves recognizing handwritten characters from images of handwritten text (i.e. scanned documents). This is an interesting task as it involves sequence learning with computer vision. The task is more difficult than Optical Character Recognition (OCR), because handwritten letters can be written in virtually infinite different styles. This thesis proposes exploiting deep learning techniques like Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN) for offline handwriting recognition. For speech recognition, we compare traditional methods for speech recognition with recent deep learning methods. Also, we apply speaker adaptation methods both at feature level and at parameter level to improve recognition of dysarthric speech
Model architectures to extrapolate emotional expressions in DNN-based text-to-speech
This paper proposes architectures that facilitate the extrapolation of emotional expressions in deep neural network (DNN)-based text-to-speech (TTS). In this study, the meaning of âextrapolate emotional expressionsâ is to borrow emotional expressions from others, and the collection of emotional speech uttered by target speakers is unnecessary. Although a DNN has potential power to construct DNN-based TTS with emotional expressions and some DNN-based TTS systems have demonstrated satisfactory performances in the expression of the diversity of human speech, it is necessary and troublesome to collect emotional speech uttered by target speakers. To solve this issue, we propose architectures to separately train the speaker feature and the emotional feature and to synthesize speech with any combined quality of speakers and emotions. The architectures are parallel model (PM), serial model (SM), auxiliary input model (AIM), and hybrid models (PM&AIM and SM&AIM). These models are trained through emotional speech uttered by few speakers and neutral speech uttered by many speakers. Objective evaluations demonstrate that the performances in the open-emotion test provide insufficient information. They make a comparison with those in the closed-emotion test, but each speaker has their own manner of expressing emotion. However, subjective evaluation results indicate that the proposed models could convey emotional information to some extent. Notably, the PM can correctly convey sad and joyful emotions at a rate of >60%
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