A method of processes audio signals picked up from a sound field by a microphone system of a listening device adapted for being worn at a particular one of the left or right ear of a user, the sound field comprising sound signals from one or more sound sources, the sound signals impinging on the user from one or more directions relative to the user. Information about a user's Ear, Head, and Torso Geometry and the user's hearing ability in combination with knowledge of the spectral profile and location of current sound sources provide the means for deciding upon which frequency bands that, at a given time, contribute most to the BEE seen by the listener or the Hearing Instrument. For a given sound source, a number of donor frequency bands is determined at a given time, where an SNR-measure for the selected signal is above a predefined threshold.