Diffusion-based Generative Modeling with Discriminative Guidance for Streamable Speech Enhancement
Chenda Li, Samuele Cornell, Shinji Watanabe, Yanmin Qian
TL;DR
This work tackles real-time speech enhancement with diffusion-based generative models by introducing discriminative guidance to drastically reduce reverse-diffusion steps and proposing a streamable, time-domain, chunk-level diffusion framework. By warm-starting the diffusion with a discriminative score for the first $N_ phi$ steps and maintaining history across chunks with SkiM, the approach achieves a favorable trade-off between generative quality and computational efficiency. Empirical results on WSJ0-CHiME3 and CHiME4 show that online performance can approach offline baselines on in-domain data while improving generalization to real-world data, with substantial reductions in MACs as $N_ phi$ increases. The proposed framework yields a practical path toward low-latency, robust streaming SE, with clear directions for latency reduction, broader applicability, and refined balance strategies between generative and discriminative components.
Abstract
Diffusion-based generative models (DGMs) have recently attracted attention in speech enhancement research (SE) as previous works showed a remarkable generalization capability. However, DGMs are also computationally intensive, as they usually require many iterations in the reverse diffusion process (RDP), making them impractical for streaming SE systems. In this paper, we propose to use discriminative scores from discriminative models in the first steps of the RDP. These discriminative scores require only one forward pass with the discriminative model for multiple RDP steps, thus greatly reducing computations. This approach also allows for performance improvements. We show that we can trade off between generative and discriminative capabilities as the number of steps with the discriminative score increases. Furthermore, we propose a novel streamable time-domain generative model with an algorithmic latency of 50 ms, which has no significant performance degradation compared to offline models.
