A new application of chaotic filter in underwater acoustic signal processing is described.After frequency modulation and high-pass IIR filtering
the chaotic signal generated by the Chua's circuit was transmitted through a underwater sound channel.The received acoustic signal shows similar frequency band characteristic with chaotic circuit.Furthermore
nonlinear dynamic analysis is applied to compare the underwater acoustic signal and the original circuit signals.The results show that the acoustic signal has more irregular phase space and higher fractal dimension than chaotic circuit signals.Chaotic filter increases the complexity of the underwater signal.