Monaural Musical Sound Separation Based on Pitch and Common Amplitude Modulation

Monaural musical sound separation has been extensively studied recently. An important problem in separation of pitched musical sounds is the estimation of time-frequency regions where harmonics overlap. In this paper, we propose a sinusoidal modeling-based separation system that can effectively resolve overlapping harmonics. Our strategy is based on the observations that harmonics of the same source have correlated amplitude envelopes and that the change in phase of a harmonic is related to the instrument's pitch. We use these two observations in a least squares estimation framework for separation of overlapping harmonics. The system directly distributes mixture energy for harmonics that are unobstructed by other sources. Quantitative evaluation of the proposed system is shown when ground truth pitch information is available, when rough pitch estimates are provided in the form of a MIDI score, and finally, when a multi-pitch tracking algorithm is used. We also introduce a technique to improve the accuracy of rough pitch estimates. Results show that the proposed system significantly outperforms related monaural musical sound separation systems.