Nonlinearity in cicada sound signals

The nonlinearity of acoustic signals produced by male cicadas and their propagation in the atmosphere using the theory of dynamical systems and partial differential equations are explored in this paper. Previous research using a Volterra equation has shown that the signal data from the vibrations of cicada tymbals and that from the recordings of the acoustic signals about 5 inches away from the cicada exhibit some nonlinear characteristics. The experimental results shown in this paper confirm the nonlinearity of the signals farther from the cicada. A number of nonlinear acoustic signal propagation models are discussed - among them the Burgers' equation which has been implemented and whose results are quite promising. © 2013 World Scientific Publishing Company.