Method and apparatus for compressing and decompressing a higher order ambisonics representation for a sound field

An apparatus for decompressing a Higher Order Ambisonics (denoted HOA) representation, the apparatus comprising:

• a decoder which perceptually decodes compressed dominant directional signals and compressed residual component signals so as to provide decompressed dominant directional signals and decompressed time domain signals representing a residual HOA component in a spatial domain;
• a re-correlator which re-correlates the decompressed time domain signals to obtain a corresponding reduced-order residual HOA component;
• a processor configured to determine a decompressed residual HOA component based on the corresponding reduced-order residual HOA component, the processor further configured to determine predicted directional signals based on at least a parameter;
• wherein the processor is further configured to determine an HOA sound field representation based on the decompressed dominant directional signals, the predicted directional signals, and the decompressed residual HOA component, and
• wherein the parameter relates to a number of active directional signals in a current frame.