Concatenative synthesis is a technique used in various applications, including speech and sound synthesis, to generate output by combining smaller units or segments.
Concatenative synthesis has been widely used in text-to-speech (TTS) systems, where speech is generated from input text. Traditional TTS systems relied on concatenating short samples of speech or using rule-based systems to convert phonetic representations into acoustic representations. With the advent of deep learning, end-to-end (E2E) systems have emerged, which can synthesize high-quality speech with large amounts of data. These E2E systems, such as Tacotron and FastSpeech2, have shown the importance of accurate alignments and prosody features for good-quality synthesis.
Recent research in concatenative synthesis has explored various aspects, such as unsupervised speaker adaptation, style separation and synthesis, and environmental sound synthesis. For instance, one study proposed a multimodal speech synthesis architecture that enables adaptation to unseen speakers using untranscribed speech. Another study introduced the Style Separation and Synthesis Generative Adversarial Network (S3-GAN) for separating and synthesizing content and style in object photographs.
In the field of environmental sound synthesis, researchers have investigated subjective evaluation methods and problem definitions. They have also explored the use of sound event labels to improve the performance of statistical environmental sound synthesis.
Practical applications of concatenative synthesis include:
1. Text-to-speech systems: These systems convert written text into spoken language, which can be used in various applications such as virtual assistants, audiobooks, and accessibility tools for visually impaired users.
2. Sound design for movies and games: Concatenative synthesis can be used to generate realistic sound effects and environmental sounds, enhancing the immersive experience for users.
3. Data augmentation for sound event detection and scene classification: Synthesizing and converting environmental sounds can help create additional training data for machine learning models, improving their performance in tasks like sound event detection and scene classification.
A company case study in this domain is Google's Tacotron, an end-to-end speech synthesis system that generates human-like speech from text input. Tacotron has demonstrated the potential of deep learning-based approaches in concatenative synthesis, producing high-quality speech with minimal human annotation.
In conclusion, concatenative synthesis is a versatile technique with applications in various domains, including speech synthesis, sound design, and data augmentation. As research progresses and deep learning techniques continue to advance, we can expect further improvements in the quality and capabilities of concatenative synthesis systems.

Concatenative Synthesis
Concatenative Synthesis Further Reading
1.The Importance of Accurate Alignments in End-to-End Speech Synthesis http://arxiv.org/abs/2210.17153v1 Anusha Prakash, Hema A Murthy2.Speech Synthesis with Neural Networks http://arxiv.org/abs/cs/9811031v1 Orhan Karaali, Gerald Corrigan, Ira Gerson3.Harmonic concatenation of 1.5-femtosecond-pulses in the deep ultraviolet http://arxiv.org/abs/1901.07805v1 Jan Reislöhner, Christoph Leithold, Adrian N. Pfeiffer4.Style Separation and Synthesis via Generative Adversarial Networks http://arxiv.org/abs/1811.02740v1 Rui Zhang, Sheng Tang, Yu Li, Junbo Guo, Yongdong Zhang, Jintao Li, Shuicheng Yan5.Multimodal speech synthesis architecture for unsupervised speaker adaptation http://arxiv.org/abs/1808.06288v1 Hieu-Thi Luong, Junichi Yamagishi6.Factor Decomposed Generative Adversarial Networks for Text-to-Image Synthesis http://arxiv.org/abs/2303.13821v1 Jiguo Li, Xiaobin Liu, Lirong Zheng7.Overview of Tasks and Investigation of Subjective Evaluation Methods in Environmental Sound Synthesis and Conversion http://arxiv.org/abs/1908.10055v1 Yuki Okamoto, Keisuke Imoto, Tatsuya Komatsu, Shinnosuke Takamichi, Takumi Yagyu, Ryosuke Yamanishi, Yoichi Yamashita8.End to End Bangla Speech Synthesis http://arxiv.org/abs/2108.00500v1 Prithwiraj Bhattacharjee, Rajan Saha Raju, Arif Ahmad, M. Shahidur Rahman9.Fault-tolerant circuit synthesis for universal fault-tolerant quantum computing http://arxiv.org/abs/2206.02691v1 Yongsoo Hwang10.Collaborative Decoding of Interleaved Reed-Solomon Codes and Concatenated Code Designs http://arxiv.org/abs/cs/0610074v2 Georg Schmidt, Vladimir R. Sidorenko, Martin BossertConcatenative Synthesis Frequently Asked Questions
What is concatenative synthesis?
Concatenative synthesis is a technique used in various applications, such as speech and sound synthesis, to generate output by combining smaller units or segments. In the context of speech synthesis, it involves concatenating short samples of recorded speech to create a continuous, natural-sounding output. This method has been widely used in text-to-speech (TTS) systems, where speech is generated from input text.
How does concatenative synthesis work in text-to-speech systems?
In text-to-speech systems, concatenative synthesis works by breaking down the input text into smaller units, such as phonemes or syllables, and then concatenating pre-recorded speech segments corresponding to these units. The system selects the most appropriate segments from a large database of recorded speech, ensuring smooth transitions between them to produce natural-sounding speech output.
What are the advantages of concatenative synthesis?
The main advantage of concatenative synthesis is its ability to produce high-quality, natural-sounding speech. Since it uses actual recordings of human speech, the output can closely resemble the original speaker's voice and intonation. Additionally, concatenative synthesis can be used to generate realistic sound effects and environmental sounds for applications like movies, games, and virtual reality experiences.
What are the limitations of concatenative synthesis?
One limitation of concatenative synthesis is the need for a large database of recorded speech segments to cover various combinations of phonemes, syllables, and prosodic features. This can make the system computationally expensive and require significant storage space. Additionally, creating a new voice or adapting to a different speaker may require recording and annotating a new set of speech samples, which can be time-consuming and labor-intensive.
How have deep learning techniques improved concatenative synthesis?
Deep learning techniques have led to the development of end-to-end (E2E) speech synthesis systems, such as Tacotron and FastSpeech2, which can synthesize high-quality speech using large amounts of data. These systems leverage deep learning models to learn accurate alignments and prosody features, resulting in more natural-sounding speech output. Furthermore, deep learning-based approaches can enable unsupervised speaker adaptation, style separation and synthesis, and environmental sound synthesis, expanding the capabilities of concatenative synthesis systems.
What are some practical applications of concatenative synthesis?
Practical applications of concatenative synthesis include: 1. Text-to-speech systems: Converting written text into spoken language for virtual assistants, audiobooks, and accessibility tools for visually impaired users. 2. Sound design for movies and games: Generating realistic sound effects and environmental sounds to enhance the immersive experience for users. 3. Data augmentation for sound event detection and scene classification: Creating additional training data for machine learning models by synthesizing and converting environmental sounds, improving their performance in tasks like sound event detection and scene classification.
What is an example of a company using concatenative synthesis?
Google's Tacotron is an example of a company using concatenative synthesis. Tacotron is an end-to-end speech synthesis system that generates human-like speech from text input. It demonstrates the potential of deep learning-based approaches in concatenative synthesis, producing high-quality speech with minimal human annotation.
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