A Predominant-F0 Estimation Method for Real-world Musical Audio Signals

In this paper we describe a robust method, called PreFEst, for estimating the fundamental frequency (F0) of melody and bass lines in monaural audio signals containing sounds of various instruments. Most previous F0-estimation methods have difficulty dealing with such complex audio signals because they are designed for mixtures of only a few sounds. Without assuming the number of sound sources, PreFEst can obtain the most predominant F0 — corresponding to the melody or bass line — supported by harmonics within an intentionally-limited frequency range. It estimates the relative dominance of every possible F0 (represented as a probability density function of the F0) and the shape of harmonic-structure tone models by using the MAP (Maximum A Posteriori Probability) estimation considering their prior distribution. Experimental results showed that a real-time system implementing this method is robust enough to detect the melody and bass lines in compact-disc recordings.