  We introduce and analyze the notion of mutual entropy-production (MEP) in
autonomous systems. Evaluating MEP rates is in general a difficult task due to
non-Markovian effects. For bipartite systems, we provide closed expressions in
various limiting regimes which we verify using numerical simulations. Based on
the study of a biochemical and an electronic sensing model, we suggest that the
MEP rates provide a relevant measure of the accuracy of sensing.
