Speech and Audio Processing

Report on Current Developments in Speech and Audio Processing

General Direction of the Field

The recent advancements in the field of speech and audio processing are marked by a significant shift towards leveraging deep learning techniques and innovative model architectures to address long-standing challenges. The focus is increasingly on developing efficient, scalable, and high-precision solutions that can operate in real-world conditions, often with limited computational resources. This trend is evident in several key areas:

  1. Efficient and Parameter-Light Models: There is a growing emphasis on creating models that are not only accurate but also computationally efficient. This is particularly important for applications where computational resources are limited, such as in mobile devices or real-time processing scenarios. Models like the attention U-Net architecture for breath sound removal exemplify this trend, offering superior performance with significantly fewer parameters and shorter training times.

  2. Diffusion-Based Generative Models: Diffusion models are gaining traction for their ability to handle complex audio tasks, such as speech enhancement and bandwidth extension. These models are being refined to better capture structural information and perform well in low Signal-to-Noise Ratio (SNR) conditions. The integration of diffusion models with other advanced techniques, such as vector quantization and sequential models, is leading to state-of-the-art performance in various audio processing tasks.

  3. Neural Speech Codecs: The development of neural speech codecs is pushing the boundaries of low-bitrate speech transmission. These codecs are designed to maintain high perceptual quality at extremely low bitrates, which is crucial for applications in telecommunications and IoT. The use of large-scale models and innovative quantization techniques is enabling significant improvements in both objective and subjective performance metrics.

  4. Information-Theoretic Approaches: There is a renewed interest in understanding and optimizing the information content of discrete speech units. Information-theoretic approaches are being used to assess the completeness and accessibility of information in these units, providing insights into how to better leverage them for tasks like speech codec and speech generation.

  5. Hybrid Models for Speech Restoration: Combining different techniques, such as noise suppression and voice conversion, is emerging as a powerful strategy for speech restoration. These hybrid models aim to enhance speech quality while preserving intelligibility, even in challenging noisy environments. The integration of diffusion-based voice conversion with noise suppression is a notable example of this approach.

  6. Inverse Problem Solving in Audio Decoding: Treating audio decoding as an inverse problem and solving it through diffusion posterior sampling is a novel approach that shows promise in improving the quality of decoded audio across various content types and bitrates. This method leverages advanced conditioning functions and model architectures to achieve significant performance improvements over traditional methods.

  7. Neuromorphic Computing for Speech Classification: The exploration of neuromorphic computing paradigms, such as the Adaptive Locally Competitive Algorithm, is opening new avenues for efficient and low-power speech classification. These approaches aim to bridge the efficiency gap between human brain processing and conventional computers, offering potential for real-time and low-power applications.

Noteworthy Papers

  • Attention-Based Efficient Breath Sound Removal: Introduces a highly efficient model for breath sound removal in vocal recordings, significantly reducing the time and expertise required for sound engineering tasks.

  • Diffusion-based Speech Enhancement with Schrödinger Bridge: Proposes a novel diffusion-based method for speech enhancement that outperforms existing models, especially in low SNR conditions.

  • BigCodec: Demonstrates a low-bitrate neural speech codec that achieves high perceptual quality at extremely low bitrates, outperforming existing codecs by a significant margin.

  • Vector Quantized Diffusion Model for Speech Bandwidth Extension: Presents a pioneering approach to speech bandwidth extension using discrete features from neural audio codecs, significantly improving speech quality.

  • Estimating the Completeness of Discrete Speech Units: Provides a comprehensive information-theoretic analysis of discrete speech units, offering insights into their information content and accessibility.

  • VC-ENHANCE: Proposes a hybrid model for speech restoration that combines noise suppression and voice conversion, achieving superior speech quality in noisy environments.

  • Audio Decoding by Inverse Problem Solving: Introduces a novel approach to audio decoding as an inverse problem, achieving significant improvements in decoded audio quality across various content types.

  • Efficient Sparse Coding with the Adaptive Locally Competitive Algorithm: Demonstrates the potential of neuromorphic computing for efficient speech classification, offering a balance between accuracy and power efficiency.

Sources

Attention-Based Efficient Breath Sound Removal in Studio Audio Recordings

Diffusion-based Speech Enhancement with Schrödinger Bridge and Symmetric Noise Schedule

BigCodec: Pushing the Limits of Low-Bitrate Neural Speech Codec

Vector Quantized Diffusion Model Based Speech Bandwidth Extension

Estimating the Completeness of Discrete Speech Units

VC-ENHANCE: Speech Restoration with Integrated Noise Suppression and Voice Conversion

Audio Decoding by Inverse Problem Solving

Efficient Sparse Coding with the Adaptive Locally Competitive Algorithm for Speech Classification