An audio encoding system, comprising: a spatial analyzer configured to receive a plurality of audio signals (W, X, Y), and to output, based thereon, decomposition parameters; an adaptive rotation stage configured to receive said plurality of audio signals and to output a plurality of rotated audio signals (E1, E2, E3) obtained by an adaptive energy-compacting orthogonal transformation, wherein quantitative properties of the transformation are determined by the decomposition parameters, and wherein the plurality of rotated audio signals and the decomposition parameters are discretely decodable into a first sound field representation; and an analysis stage configured to output, based on said plurality of audio signals, a time-variable gain profile (g) comprising at least one frequency-variable component for attenuating non-voice content when applied to at least one of the plurality of rotated audio signals, wherein the analysis stage is further adapted to output, based on said plurality of audio signals, spatial parameters (Th) adapted for use in spatial synthesis of a first rotated audio signal, or a modified version of the first rotated audio signal, into a second sound field representation different from the first sound field representation, wherein said first rotated audio signal is comprised in said plurality of rotated audio signals, wherein the audio encoding system is operable to suspend output of a set of signals selected from the group comprising: said decomposition parameters and all of said plurality of rotated audio signals, except a first rotated audio signal; and said spatial parameters, said decomposition parameters and all of said plurality of rotated audio signals, except said first rotated audio signal. a spatial analyzer configured to receive a plurality of audio signals (W, X, Y), and to output, based thereon, decomposition parameters; an adaptive rotation stage configured to receive said plurality of audio signals and to output a plurality of rotated audio signals (E1, E2, E3) obtained by an adaptive energy-compacting orthogonal transformation, wherein quantitative properties of the transformation are determined by the decomposition parameters, and wherein the plurality of rotated audio signals and the decomposition parameters are discretely decodable into a first sound field representation; and an analysis stage configured to output, based on said plurality of audio signals, a time-variable gain profile (g) comprising at least one frequency-variable component for attenuating non-voice content when applied to at least one of the plurality of rotated audio signals, wherein the analysis stage is further adapted to output, based on said plurality of audio signals, spatial parameters (Th) adapted for use in spatial synthesis of a first rotated audio signal, or a modified version of the first rotated audio signal, into a second sound field representation different from the first sound field representation, wherein said first rotated audio signal is comprised in said plurality of rotated audio signals, wherein the audio encoding system is operable to suspend output of a set of signals selected from the group comprising: said decomposition parameters and all of said plurality of rotated audio signals, except a first rotated audio signal; and said spatial parameters, said decomposition parameters and all of said plurality of rotated audio signals, except said first rotated audio signal. said decomposition parameters and all of said plurality of rotated audio signals, except a first rotated audio signal; and said spatial parameters, said decomposition parameters and all of said plurality of rotated audio signals, except said first rotated audio signal.