A method comprising: obtaining a first audio direction parameter value for each sub-band of a sub-frame of a frame of an audio signal; obtaining a second audio direction parameter value for the sub-frame of the frame of the audio signal for one or more audio objects associated with said audio signal; and determining a bit-efficient encoding for each first audio direction parameter value of the sub-frame based on a similarity between the first audio direction parameter value for each sub-band and the second audio direction parameter values for the one or more audio objects.