An acoustic processor for a mobile device is described the mobile device comprising a speaker including a speaker membrane, the speaker membrane having a first speaker membrane side and second speaker membrane side opposite the first speaker membrane side, a mobile device housing for providing a first acoustic path between the first speaker membrane side and the exterior of the mobile device and a second acoustic path between the second speaker membrane side and the exterior of the mobile device, the acoustic processor being configured and arranged to sense a signal on an acoustic processor input, the signal being induced on at least one terminal of the speaker in response to acoustic waves process the induced signal to discriminate between acoustic waves from different directions; and output the processed signal on an acoustic processor output.