In this paper the possibilities of channel-error protection for transmission of CELP-coded speech over highly disturbed channels without additional bits for error-control are discussed. Algorithms are given which do not require explicit channel models and work without additional delay and almost no additional complexity. Time-based and mutual dependencies of the speech codec parameters are exploited for channel-error detection and parameter extrapolation at the decoder. The algorithms are optimized by informal listening tests rather than by maximization of a mathematically tractable measure.