The invention relates to a method and an apparatus in which samples of at least a part of an audio signal of a first channel and a part of an audio signal of a second channel are used to produce a sparse representation of the audio signals to increase the encoding efficiency. In an example embodiment one or more audio signals are input and relevant auditory cues are determined in a time-frequency plane. The relevant auditory cues are combined to form an auditory neurons map. Said one or more audio signals are transformed into a transform domain and the auditory neurons map is used to form a sparse representation of said one or more audio signal.