Plosive Enhancement Using Phase Linearization and Smoothing

Abstract:
Despite their small share in overall signal energy, plosives have been previously shown to be important for speech perception. We propose a simple, yet effective, model-based phase-aware speech enhancement approach specifically targeted at plosives. Starting from a model of the plosive burst as a unit impulse, we introduce three phase enhancement schemes: simple replacement of the noisy phase with a linear function, linear regression, as well as smoothing by local polynomial regression. To improve the outcome and compensate for model mismatch we also propose an SNR-based weighting. All schemes are evaluated under both oracle and realistic conditions, showing a consistent improvement in instrumentally predicted speech quality and, to a lesser degree, speech intelligibility. When only frames containing plosives are considered, a segmental SNR improvement of 2 dB to 6 dB can be observed, depending on the input SNR.