A beamforming audio capture apparatus comprises a microphone array (301) which is coupled to a first beamformer (303) and a second beamformer (305). The beamformers (303, 305) are filter-and-combine beamformers comprising a plurality of beamform filters each having an adaptive impulse response. A difference processor (309) determines a difference measure between beams of the first beamformer (303) and the second beamformer (305) in response to a comparison of the adaptive impulse responses of the two beamformers (303, 305). The difference measure may e.g. be used to combine the output signals of the beamformers (303, 305). An improved difference measure less sensitive to e.g. diffuse noise may be provided.