of constraints on the encoding operations of a speech parameter quantizer at the decoder the decoded speech parameter is compared against the same set of constraints and if a violation of the constraints is detected the decoder declares that the decoded speech parameter is invalid due to bit errors the decoded speech parameter is then discarded and substituted by a suitable replacement value obtained from adjacent decoded speech parameters that are assumed to be valid the set of constraints is selected such that 1 it is rarely or never violated in the encoder while encoding natural speech and 2 when it is violated in the decoder after enforcing the constraints in the encoder it corresponds to a bit error corrupted speech parameter that is likely to produce significant degradation in the output speech if the set of constraints is selected to detect most of the bit errors that degrade quality significantly it is likely that the constraints will also degrade speech quality somewhat when there are no bit errors i e clear channel selecting the constraints involves a trade off between clear channel performance and noisy channel performance thus the objective in designing such a bit error concealment system is to choose a suitable set of constraints that will allow the system to detect as many quality degrading bit errors as possible while causing negligible degradation to the clear channel codec performance the exemplary embodiment of the present invention described below achieves this goal fig1 and 2 are flowcharts of the general encoding and decoding processes of the instant invention in fig1 the input parameter.