It is shown by means of numerical simulations that aperiodic stochastic res
onance occurs in chaotic one-dimensional maps with various kinds of intermi
ttency. The effect appears in the absence of external noise, as the system
control parameter is varied. In the case of input signals slowly varying in
time the analytic treatment, using the adiabatic approximation based on th
e expressions for the mean laminar phase duration, yields the input-output
covariance function comparable with numerical results. (C) 1998 American In
stitute of Physics. [S1054-1500(98)00304-8].