In this paper, a watermark scheme for detecting and recovering the tampering of speech signal is proposed. We embed an approximate version of the origin information into the less significant bits (LSBs). When the watermarked signal is tampered, we can localize the tampered area and exclude from the area, recovery the original one from the approximate version. Based the embedded information, we estimate the origin signal by solving a liner equation with Least Square QR-factorization (LSQR) method. The result of an informal listening test shows that 83.7% listening material is intelligible after recovery with 20% part tampered.