A method of decoding a compressed Higher Order Ambisonics representation of a sound or sound field, the method comprising: receiving a bitstream containing the compressed HOA representation corresponding to a plurality of hierarchical layers that include a base layer and two or more hierarchical enhancement layers (1300-1, 1300-(M-1)), wherein the bit stream comprises, in each layer, a respective HOAextension payload includingside information for parametrically enhancing a reconstructed HOA representation obtainable from the transport signals assigned to the respective layer and any layers lower than the respective layer, wherein the HOA extension payload includes bit stream elements for a HOA spatial signal prediction decoding tool; determining a highest usable layer among the plurality of layers for decoding based on a set of invalid layer indices which indicate layers that have not been validly received, wherein the highest usable layer is the layer below the lowest layer that has not been validly received as indicated by a smallest index in the set of invalid layer indices; extracting a HOA extension payload assigned to the highest usable layer, wherein the HOA extension payload includes side information for parametrically enhancing a reconstructed HOA representation corresponding to the highest usable layer, wherein the reconstructed HOA representation corresponding to the highest usable layer is obtainable on the basis of the transport signals assigned to the highest usable layer and any layers lower than the highest usable layer; decoding the compressed HOA representation corresponding to the highest usable layer based on layer information, the transport signals assigned to the highest usable layer and any layers lower than the highest usable layer; and parametrically enhancing the decoded HOA representation using the side information included in the HOA extension payload assigned to the highest usable layer, but not using any side information included in HOA extension payload assigned to any layers lower than the highest usable layer. receiving a bitstream containing the compressed HOA representation corresponding to a plurality of hierarchical layers that include a base layer and two or more hierarchical enhancement layers (1300-1, 1300-(M-1)), wherein the bit stream comprises, in each layer, a respective HOAextension payload includingside information for parametrically enhancing a reconstructed HOA representation obtainable from the transport signals assigned to the respective layer and any layers lower than the respective layer, wherein the HOA extension payload includes bit stream elements for a HOA spatial signal prediction decoding tool; determining a highest usable layer among the plurality of layers for decoding based on a set of invalid layer indices which indicate layers that have not been validly received, wherein the highest usable layer is the layer below the lowest layer that has not been validly received as indicated by a smallest index in the set of invalid layer indices; extracting a HOA extension payload assigned to the highest usable layer, wherein the HOA extension payload includes side information for parametrically enhancing a reconstructed HOA representation corresponding to the highest usable layer, wherein the reconstructed HOA representation corresponding to the highest usable layer is obtainable on the basis of the transport signals assigned to the highest usable layer and any layers lower than the highest usable layer; decoding the compressed HOA representation corresponding to the highest usable layer based on layer information, the transport signals assigned to the highest usable layer and any layers lower than the highest usable layer; and parametrically enhancing the decoded HOA representation using the side information included in the HOA extension payload assigned to the highest usable layer, but not using any side information included in HOA extension payload assigned to any layers lower than the highest usable layer.