In this paper, we consider single-channel speech enhancement in the short time Fourier transform (STFT) domain. We suggest to improve an STFT phase estimate by estimating the initial phases. The method is based on the harmonic model and a model for the phase evolution over time. The initial phases are estimated by setting up a least squares problem between the noisy phase and the model for phase evolution. Simulations on synthetic and speech signals show a decreased error on the phase when an estimate of the initial phase is included compared to using the noisy phase as an initialisation. The error on the phase is decreased at input SNRs from -10 to 10 dB. Reconstructing the signal using the clean amplitude, the mean squared error is decreased and the PESQ score is increased.
Bibliographic reference. Nørholm, Sidsel Marie / Krawczyk-Becker, Martin / Gerkmann, Timo / Par, Steven van de / Jensen, Jesper Rindom / Christensen, Mads Græsbøll (2015): "Least squares estimate of the initial phases in STFT based speech enhancement", In INTERSPEECH-2015, 1750-1754.