Derivation of Wiener filters which are spatially optimal for
reverberant sound fields is presented in this paper, with an
application to two-microphone noise cancellation in reverberant
rooms. The optimal filters which are derived from the spatial
correlation of diffuse sound fields capture the local behaviour of
the sound field and are therefore of lower order and potentially
more spatially robust than conventional adaptive noise
cancellation filters in reverberant rooms. Formulations for
unconstrained and causally constrained optimal filters are
presented, and an example application to a two-microphone speech
enhancement is demonstrated using a computer simulation.
