A method and apparatus for processing object-based audio signals is provided. The apparatus receives a plurality of object-based audio signals. Each object-based audio signal of the object-based audio signals includes audio waveform data and object metadata associated with the audio waveform data. The object metadata includes at least one of a loudness parameter or a power parameter associated with the audio waveform data. The apparatus determines a loudness metric based on the received object-based audio signals and based on the at least one of the loudness parameter or the power parameter for each object-based audio signal of the received object-based audio signals. In one configuration, the apparatus renders the received object-based audio signals to a set of output signals based on the determined loudness metric. In another configuration, the apparatus transmits (e.g., broadcast, file delivery, or streaming) the received object-based audio signals based on the determined loudness metric.