In this paper, we propose a frame erasure concealment algorithm based on re
estimating gain parameters for a code-excited linear prediction (CELP) code
r. When a frame is detected as being erased, the coding parameters, especia
lly the adaptive codebook gain and fixed codebook gain, of the erased and s
ubsequent frames, are reestimated by a gain-matching procedure. By doing th
is, we can reduce the abrupt change caused in the decoded excitation signal
by a simple scaling down procedure. We have applied this technique to the
IS-641 speech coder and found that the proposed algorithm improves the spee
ch quality under various channel conditions compared with the conventional
extrapolation-based concealment algorithm.