1. A method of computing beamformer coefficients at a device, the method comprising: storing a plurality of sets of theoretical statistical data for a respective plurality of theoretical signals in a store, each theoretical signal having its own particular attributes, the statistical data being for use in computing beamformer coefficients for application by a beamformer to signals received at the device; receiving signals at an input of the device; determining, for the plurality of theoretical statistical data sets, a respective plurality of weights based on an analysis of the extent to which the received signals have the particular attributes of the theoretical signals; retrieving the plurality of theoretical statistical data sets from the store; calculating a statistical data set for the received signals by performing a weighted sum of the retrieved plurality of theoretical statistical data sets using the determined respective plurality of weights; and computing beamformer coefficients based on the calculated statistical data set for the received signals, said beamformer coefficients being for application by a beamformer to the received signals for generating a beamformer output.