Analysis of the responses of a flush‐mounted transducer system to the pressure field in a turbulent boundary layer and to the boundary pressure field induced by an incident plane acoustic wave is formulated and discussed. The transducer system is considered as a spatial and a spectral filter. The properties of the filters are defined and illustrated for the case where the system consists of nominally identical transducers. The analysis is limited to geometries where the centers of the transducers are regular y placed at the centers of a plane rectangular grid. Time delays between transducers are allowed for in this analysis.