Multi-Stage Progressive Audio Bandwidth Extension

Audio bandwidth extension can enhance subjective sound quality by increasing bandwidth of audio signal. This paper presents a novel multi-stage progressive method for time domain causal bandwidth extension. Each stage of the progressive model contains a light weight scale-up module to generate high frequency signal and a supervised attention module to guide features propagating between stages. Time-frequency two-step training method with weighted loss for progressive output is adopted to supervise bandwidth extension performance improves along stages. Test results show that multi-stage model can improve both objective results and perceptual quality progressively. The multi-stage progressive model makes bandwidth extension performance adjustable according to energy consumption, computing capacity and user preferences.