An information reproduction apparatus using maximum likelihood decoding for calculating likelihood of a value of a reproducing signal to a plurality of reference values, the reproducing signal obtained from a recording medium, to decode the reproducing signal on the basis of the likelihood, the apparatus includes a circuit for detecting the reproducing signal from the recording medium, a circuit for detecting the reference values corresponding to a characteristic of the reproducing signal, and a correction circuit for correcting the reproducing signal or the calculated likelihood according to the detected reference values.