An apparatus comprising means configured to: generate spatial audio signal directional metadata parameters for time-frequency tiles of an audio frame; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a first quantization resolution; compare a number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution against a determined number of bits; output or store the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is less than the determined number of bits; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a second quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is more than the determined number of bits and a difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is less than a determined threshold; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a third quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is more than the determined number of bits and the difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is greater than the determined threshold, wherein the third quantization resolution is determined such that a number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the third quantization resolution is equal to or less than the determined number of bits. generate spatial audio signal directional metadata parameters for time-frequency tiles of an audio frame; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a first quantization resolution; compare a number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution against a determined number of bits; output or store the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is less than the determined number of bits; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a second quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is more than the determined number of bits and a difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is less than a determined threshold; generate encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on a third quantization resolution when the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is more than the determined number of bits and the difference between the determined number of bits and the number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the first quantization resolution is greater than the determined threshold, wherein the third quantization resolution is determined such that a number of bits used for the encoded spatial audio signal directional metadata parameters for the time-frequency tiles of the audio frame based on the third quantization resolution is equal to or less than the determined number of bits.