least one azimuth index and/or at least one elevation index for a last sub-band based on the reduced distribution allocation of bits. 

The apparatus caused to entropy encode the at least one azimuth index and/or at least one elevation index based on the number of bits required to entropy encode the at least one azimuth index and/or at least one elevation index may further be caused to Golomb Rice encode with two GR parameter values. 

The apparatus caused to encode 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 be caused to uniformly reduce 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. 

The apparatus caused to encode 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 be caused to perform at least one of: assign indexes for encoding in increasing order of the distance from the frontal direction; assign the index in increasing order of the azimuth value. 

The apparatus may be further caused to perform: store and/or transmit 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 sixth aspect there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive 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; decode the 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 

