In this paper, we propose new estimation technique of voice source and vocal-tract parameters in voiced speech. First, Kalman filtering technique which is a new approach to time-varying analysis is examined. Second, in order to overcome the problems of Kalman filtering approach, the error covariance matrix in Kalman filter is decomposed by reduced-rank SVD(singular value decomposition). Third, in order to estimate more accurate vocal-tract parameters we introduce robustness concept which assumes residual characteristics as normal mixture density. And, finally we propose wave-shaping filter bank approach as a new voice source modeling method which can represents and controls various source characteristics in frequency domain. The proposed methods give more accurate and more various time-varying voice parameters. These methods can be used to improve the speech quality in speech synthesis and coding techniques.