An example device configured to obtain image data includes a memory configured to store one or more priority values, each of the one or more priority values being associated with a type of image object associated with the image data. The device includes one or more processors coupled to the memory, and configured to associate image objects in the image data with one or more audio sources represented in one or more audio streams. The one or more processors are also configured to assign a respective priority value to each of the one or more audio sources represented in the one or more streams and code ambisonic coefficients based on the assigned priority value.