A novel approach combining Decision Directed(DD) estimation and Predicted(PD) estimation was proposed to improve the priori Signal to Noise Ratio(SNR) estimation for speech enhancement in noisy environments. PD estimation incorporated the soft-decision scheme and speech presence uncertainty. In contrast to the conventional DD-based scheme, a less speech distortion was achieved when a posteriori SNR was higher; while a further reduction of musical noise was achieved when a posteriori SNR was lower. It was also found that a special case of the proposed method had been degenerated to the DD estimation with a weighting factor. Experimental results demonstrated the improved performance of the proposed algorithm.