Julius Richter, Danilo de Oliveira, Timo Gerkmann
Generative speech enhancement has recently shown promising advancements in improving speech quality in noisy environments. Multiple diffusion-based frameworks exist, each employing distinct training objectives and learning techniques. This paper aims to explain the differences between these frameworks by focusing our investigation on score-based generative models and the Schr\"odinger bridge. We conduct a series of comprehensive experiments to compare their performance and highlight differing training behaviors. Furthermore, we propose a novel perceptual loss function tailored for the Schr\"odinger bridge framework, demonstrating enhanced performance and improved perceptual quality of the enhanced speech signals. All experimental code and pre-trained models are publicly available to facilitate further research and development in this domain.
| Task | Dataset | Metric | Value | Model |
|---|---|---|---|---|
| Speech Enhancement | VoiceBank + DEMAND | PESQ (wb) | 3.7 | Schrödinger bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | DNSMOS | 3.72 | Schrödinger Bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | ESTOI | 0.73 | Schrödinger Bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | PESQ-WB | 3.09 | Schrödinger Bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | POLQA | 3.71 | Schrödinger Bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | SI-SDR | 16.29 | Schrödinger Bridge (PESQ loss) |
| Speech Enhancement | EARS-WHAM | SIGMOS | 3.18 | Schrödinger Bridge (PESQ loss) |