GSM AMR_WB speech codec being used for both Internet and mobile networks, robustness to both frame erasures and random bit errors assumes significance. This paper presents a high-performance concealment algorithm for AMR_WB speech. The proposed algorithm includes using Mutipulse-based Forward Error correction technique at encoder to address the error propagation cased by the Adaptive codebook. And at the decoded side, to alleviate audible artifacts at the boundary between the previous and the current frame by modificating the pitch contour of the current frame. The algorithm has been implemented in the AMR_WB 12.56kb/s standard. Subjective tests have demonstrated that this improves perceived quality in the presences of frame erasures.