  We present an experimental study of stochastic resonance in an electronic
Chua circuit operating in the chaotic regime. We study in detail the
switch-phase distribution and the phase-shift between sinusoidal forcing for
two responses of the circuit: one depending on both inter-well and intra-well
dynamics and the other depending only on inter-well dynamics. We describe the
two relevant de-synchronizatrion mechanisms for high and low frequencies of the
forcing and present a method to detect the optimal noise intensity from switch
phases which coincides with the one derived from the observation of the
signal-to-noise ratio or residence times.
