  I describe the new instrumentation for the SIMPLE dark matter search
experiment, and its use in identifying, validating and rejecting non-WIMP
backgrounds in the first stage of the Phase II project measurements. Beyond
intrinsic acoustic background discrimination, evidence is provided for
discrimination between {\alpha}- and neutron-induced events via analysis of the
signal parameters. Analysis of the first stage result of the Phase II
measurements yields 14 events associated with the ambient neutron field,
consistent with MCNP simulations which include all materials radio-assays and
full measurement shielding.
