A method and apparatus for distributed speech recognition serve to mitigate the effect of transmission errors. The method comprises the steps of identifying speech recognition parameters which have been subjected to a transmission error, and processing data to be sent to the speech recognition decoder to ensure that any speech recognition parameters which have been subjected to such an error are excluded from back-end processing. The speech recognition parameters which have been subjected to transmission errors are excluded from back-end processing by replacing those parameters with data which is selected so as to be rejected by the speech recognition decoder as abnormal and/or non-speechlike.