Speech Processing and Voice Conversion

Report on Current Developments in Speech Processing and Voice Conversion

General Direction of the Field

The field of speech processing and voice conversion is witnessing significant advancements, particularly in the areas of low-resource language support, zero-shot learning, and the integration of innovative techniques such as self-supervised learning (SSL) and transfer learning. Researchers are focusing on developing systems that can handle diverse accents, languages, and speech domains with minimal supervision and data requirements. The emphasis is on creating more natural and personalized speech interfaces, with a growing interest in the quality of speaker similarity and the comprehensibility of non-native speech.

Key Innovations and Advances

  1. Low-Resource Language Support: There is a notable shift towards developing voice cloning and text-to-speech (TTS) systems that can operate in low-resource languages. Techniques such as transfer learning and SSL are being leveraged to overcome the challenges of limited data availability and poor audio quality. These systems are designed to produce high-quality speech with minimal training data, making them suitable for diverse linguistic contexts.

  2. Zero-Shot Learning and Accent Conversion: The development of zero-shot learning frameworks for accent conversion is gaining traction. These frameworks aim to convert speech accents with minimal supervision, using innovative techniques such as semantic token-based conversion and generative models. The decoupling of semantic tokens from speech synthesis allows for the use of large-scale target accent speech datasets, reducing the need for parallel data.

  3. Self-Supervised Learning (SSL) and Speech Representation: SSL is emerging as a powerful tool for speech representation learning. Models like HuBERT are being modified to better capture non-content information, such as prosody and speaker identity. Robust data augmentation strategies are also being explored to enhance the performance of SSL models on tasks that require effective modeling of other speech information.

  4. Disentangling Segmental and Prosodic Factors: There is a growing interest in disentangling the segmental and prosodic characteristics of non-native speech to improve comprehensibility and social attitudes. Systems are being developed to independently manipulate these factors, providing insights into their individual contributions to speech perception.

  5. Voice Conversion in Specific Domains: The exploration of voice conversion in specific speech domains, such as whispered speech, is an emerging area of research. Models are being designed to perform zero-shot voice conversion in these domains while maintaining high speaker similarity and speech quality.

Noteworthy Papers

  • Advancing Voice Cloning for Nepali: Utilizes transfer learning to enhance voice cloning in a low-resource language, addressing issues of poor audio quality and data scarcity.
  • Convert and Speak: Proposes a zero-shot accent conversion framework that achieves state-of-the-art performance with minimal supervision, demonstrating high adaptability and scalability.
  • SSL-TTS: Introduces a lightweight zero-shot TTS framework that leverages SSL features and retrieval methods, achieving performance comparable to state-of-the-art models with significantly less training data.
  • LCM-SVC: Accelerates inference speed in singing voice conversion using latent consistency distillation, maintaining high sound quality and timbre similarity.

These papers represent significant strides in the field, showcasing innovative approaches and promising results that advance the development of more natural and personalized speech interfaces.

Sources

Advancing Voice Cloning for Nepali: Leveraging Transfer Learning in a Low-Resource Language

Convert and Speak: Zero-shot Accent Conversion with Minimum Supervision

Hear Your Face: Face-based voice conversion with F0 estimation

SSL-TTS: Leveraging Self-Supervised Embeddings and kNN Retrieval for Zero-Shot Multi-speaker TTS

Speech Representation Learning Revisited: The Necessity of Separate Learnable Parameters and Robust Data Augmentation

Disentangling segmental and prosodic factors to non-native speech comprehensibility

Improvement Speaker Similarity for Zero-Shot Any-to-Any Voice Conversion of Whispered and Regular Speech

Prosody of speech production in latent post-stroke aphasia

Developing vocal system impaired patient-aimed voice quality assessment approach using ASR representation-included multiple features

LCM-SVC: Latent Diffusion Model Based Singing Voice Conversion with Inference Acceleration via Latent Consistency Distillation

Which Prosodic Features Matter Most for Pragmatics?

NEST: Self-supervised Fast Conformer as All-purpose Seasoning to Speech Processing Tasks

A layer-wise analysis of Mandarin and English suprasegmentals in SSL speech models