Phase synchronization of stochastic self-oscillations by a periodic external signal

Theoretical and experimental results are presented concerning the effect of an external periodic signal on stochastic self-oscillations, represented as an oscillatory process with random amplitude and phase modulation. A description is given of the phase synchronization effect, consisting in a partial suppression of the phase diffusion. In the power spectrum this effect corresponds to the appearance of a discrete component at the narrow peak; the broadband part of the spectrum is practically invariant.