An audio apparatus comprises a first receiver (501) receiving audio data for sources of a scene comprising acoustic environments divided by acoustically attenuating boundaries. A second receiver (503) receives metadata comprising a position indication for a transfer region of an acoustically attenuating boundary between a first acoustic environment and a second acoustic environment with the transfer region having less acoustic attenuation than the boundary. The metadata further includes an energy transfer indication for the transfer region indicating the proportion of energy at the transfer region from an omnidirectional point audio source at a reference position. A renderer (507) renders an audio signal for a position in the first acoustic environment by rendering audio data for a source of the second acoustic environment and adapting a level of the audio depending on the energy transfer indication. The level may be adapted based on a difference between a source position and the reference position.