A method of encoding a signal, particularly a message signal for speech and/or image transmission, in which signal-matched encoding of the signal with M bits is performed using Q quantization levels, with Q<2M, and in which at least part of the remaining bit rate or the entire redundancy of M−Id(Q) bits is used to protect the signal against errors. The error protection uses a nonlinear code, for example. Furthermore, additional, signal-matched code redundancy can be added to an arbitrary source-coded signal. To decode the redundant signals in both cases, parameter estimation is performed at the receiving end using at least part of the redundancy.