Encoding on a sub-band-by-sub-band basis by determining a reduced distribution of the third number of bits on a sub-band-by-sub-band basis, the reduced estimate based on the initial estimate and the defined allocation of the second number of bits may further comprise uniformly reducing on a sub-band-by- sub-band basis an allocation of bits for encoding the at least one azimuth index and/or at least one elevation index. Encoding the at least one azimuth value and/or at least one elevation value of the frame based on a defined allocation of a third number of bits from the first number of bits, wherein the third number of bits is variably distributed on a sub- band-by-sub-band basis may further comprise at least one of: assigning indexes for encoding in increasing order of the distance from the frontal direction; assigning the index in increasing order of the azimuth value. The method may further comprise: storing and/or transmitting the encoded at least one energy ratio value and at least one azimuth value and/or at least one elevation value of the frame. According to a fourth aspect there is provided a method comprising: receiving encoded values for sub-bands of a frame of an audio signal, the values comprising at least one azimuth index, at least one elevation index and at least one energy ratio value for each sub-band; decoding encoded values of the frame based on a defined allocation of bits wherein decoding the at least one azimuth index and/or at least one elevation index of the frame uses a variably distributed bit allocation on a sub- band-by-sub-band basis. Decoding the at least one azimuth index and/or at least one elevation index of the frame uses a variably distributed bit allocation on a sub-band-by-sub-band basis may further comprise: determining an initial allocation of bits distribution used to decode the at least one azimuth index and/or at least one elevation index for each sub-band based on the at least one energy ratio value for each sub-band; determining a reduced allocation of bits distribution based on the initial allocation of bits distribution and an allocation of bits distribution for decoding at least one energy