A signal reproduction apparatus configured to reproduce, from an input signal containing a weak signal which is a piece of transmission information and noise superimposed thereon, the weak signal through use of a stochastic resonance phenomenon, said signal reproduction apparatus comprising: at least one nonlinear element (NL, NL 1...NL N, NLD 1...NLD N), with a nonlinear operation characteristic, which is configured to generate and output a nonlinear output signal (NLO, NLO 1...NLO N, DS 1...DS N) based on an input of the at least one nonlinear element; N branch lines which are configured to split at least one of the input signal and the nonlinear output signal to N split signals, with N being a natural number equal to or greater than 2, the at least one nonlinear element being configured to receive the input signal or one split signal of the N split signals; N delay elements (D 1...D N, NLD 1...NLD N), each one of the N delay elements arranged in a respective different one of the N branch lines and each one of the N delay elements connected with the at least one nonlinear element in series, which are configured to respectively delay a respective input of each one of the N delay elements with respective different delay times (Δt 1...Δt N) and to respectively output N delay signals (DS 1...DS N); and a combiner which is configured to combine N processed signals, obtained at respective outputs of the N branch lines by passing them through the at least one nonlinear element and each one of the N delay elements, into a single delayed combined signal, characterized in that a minimum delay time difference among differences between the respective different delay times of respective pairs of the N delay elements is greater than an autocorrelation time of the noise superimposed on the weak signal, and a maximum delay time difference among the differences between the respective different delay times of the respective pairs of the N delay elements is equal to or less than 1/, where f is a maximum frequency of the weak signal to be reproduced. at least one nonlinear element (NL, NL 1...NL N, NLD 1...NLD N), with a nonlinear operation characteristic, which is configured to generate and output a nonlinear output signal (NLO, NLO 1...NLO N, DS 1...DS N) based on an input of the at least one nonlinear element; N branch lines which are configured to split at least one of the input signal and the nonlinear output signal to N split signals, with N being a natural number equal to or greater than 2, the at least one nonlinear element being configured to receive the input signal or one split signal of the N split signals; N delay elements (D 1...D N, NLD 1...NLD N), each one of the N delay elements arranged in a respective different one of the N branch lines and each one of the N delay elements connected with the at least one nonlinear element in series, which are configured to respectively delay a respective input of each one of the N delay elements with respective different delay times (Δt 1...Δt N) and to respectively output N delay signals (DS 1...DS N); and a combiner which is configured to combine N processed signals, obtained at respective outputs of the N branch lines by passing them through the at least one nonlinear element and each one of the N delay elements, into a single delayed combined signal, characterized in that a minimum delay time difference among differences between the respective different delay times of respective pairs of the N delay elements is greater than an autocorrelation time of the noise superimposed on the weak signal, and a maximum delay time difference among the differences between the respective different delay times of the respective pairs of the N delay elements is equal to or less than 1/, where f is a maximum frequency of the weak signal to be reproduced.