Error detecting device for viterbi decoder

An error detecting device of received digital data solves a problem for detecting errors in a conventional device in that error detection following the Viterbi decoding performed on most important bits cannot detect errors even if they include a considerable amount of errors, and that odd sounds result from decoding of voice data, for example. The present error detecting device includes a Viterbi decoder for carrying out the Viterbi decoding of the received digital data, an error number decision portion for comparing a threshold value with the number of errors of the path metric obtained by the Viterbi decoding, and a voice decoder for decoding the received digital data, on which the error number decision portion decides that the number of errors is below the threshold value.