  Via constructing an explicit Lagrangian for which the perturbation equations
are analogues of a scalar field propagating in a planar black hole space-time,
it is found that all planar black holes conformal to a Painlev\'e-Gullstrand
type line element can be realized as analogue metrics. This is valid for an
arbitrary choice of conformal and blackening factor, thereby vastly extending
the number of known examples of explicitly known analogue metrics.
