## CLAIMS: 

1. An apparatus comprising means for: 

receiving values for sub-bands of a frame of an audio signal, the values comprising at least one azimuth value, at least one elevation value and at least one energy ratio value for each sub-band; 

determining an allocation of first number of bits to encode the values of the frame, wherein the first number of bits are fixed; 

encoding the at least one energy ratio value of the frame based on a defined allocation of a second number of bits from the first number of bits; 

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. 

2. The apparatus as claimed in claim 1, wherein the means for encoding the at least one energy ratio values of the frame based on a defined allocation of a second number of bits from the first number of bits is further for: 

generating a weighted average of the at least one energy ratio value; 

encoding the weighted average of the at least one energy ratio value based on the second number of bits. 

3. The apparatus as claimed in claim 2, wherein the means for encoding the weighted average of the at least one energy ratio value based on the second number of bits is further for scalar non-uniform quantizing the at least one weighted average of the at least one energy ratio value. 

4. The apparatus as claimed in any of claims 1 to 3, wherein the means for 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 

