International Journal of Computer Science Issues

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Fundamental frequency estimation is very essential in Carnatic music signal processing as it is the basic component that needs to be used to determine the melody string of the signal after estimating the other frequency components. In this work a new algorithm to estimate the fundamental frequency of Carnatic music songs and film songs based on Carnatic music is proposed and implemented. The algorithm is based on the biological mutation theory which is implemented using the characteristics of Carnatic music where the concept of neutral mutations is adopted. Hence, the principle used is that, the signal characteristics do not change if it is mutated with another signal having the same frequency components. For determination of the fundamental frequency the three features namely, MFCC, spectral flux, and centroid of the original are estimated. The mutating signal is derived in a similar manner musicians adjust their singing frequency range for a particular song. The prerecorded 'S', 'P', 'S' is used for mutating the input signal at three positions namely, beginning, middle and end. Then the same set of features namely MFCC, spectral flux, and centroid are also extracted for the mutated signal. Then by comparing the features of the original signal with the mutated signal, the signal which matches closely with the features of the original signal in all the three positions is identified and the frequency corresponding to the lower 'S' of the signal which is used for mutating is identified as the fundamental frequency of the input signal. This algorithm was evaluated using the measures of Harmonic Error, Absolute difference between mean pitches and Absolute difference in standard deviation and it was observed that the proposed algorithm yielded a better result than the existing algorithms for estimating fundamental frequency, for the input considered.