In this paper an artificial stereo extension method is proposed to provide stereophonic
sound from mono sound. While frame-independent artificial stereo extension methods, such
as Gaussian mixture model (GMM)-based extension, do not consider the correlation of
energies of previous frames, the proposed stereo extension method employs a minimum
mean-squared error estimator based on a hidden Markov model (HMM) for the incorporation
of non-stationary energy trajectory. The performance of the proposed stereo extension …