Suppose $M$ is a compact orientable aspherical manifold and $G$ its fundamental group. Is there a nice description of representatives of the fundamental class of $M$ and its dual in the (homogenous) bar complex of $G$?

If $M$ is negatively curved and one fixes a base point in $\tilde{M}$ one can probably map an $n+1$-tuple of group elements to the volume of their convex hull in $\tilde{M}$ to get a representative of the dual fundamental class, but I don't see how this extends to the non negatively curved case.