Drum transcription with non-negative spectrogram factorisation

This paper describes a novel method for the automatic transcription of drum sequences. The method is based on separating the target drum sounds from the input signal using non-negative matrix factorisation, and on detecting sound onsets from the separated signals. The separation algorithm factorises the spectrogram of the input signal into a sum of instrument spectrograms, each having a fixed spectrum and a time-varying gain. The spectra are calculated from a set of training signals, and the time-varying gains are estimated with an algorithm stemming from non-negative matrix factorisation. Onset times of the instruments are detected from the estimated time-varying gains. The system gave better results than two state-of-the-art methods in simulations with acoustic signals containing polyphonic drum sequences, and overall hit rate of 96% was accomplished. Demonstrational signals are available at http://www.cs.tut.fi/~paulus/demo/.