Entropy decay as a measure of stochasticity in chaotic systems

The series of truncated entropies, approaching the Kolmogorov-Sinai entropy when correlations between increasingly distant signals are taken into account, is considered. A general expression for the related characteristic time is obtained for one-dimensional maps. Evaluating it analytically near the state of maximal entropy and at intermittency we find it reflecting faithfully the degree of stochasticity.