An audio asset library containing audio assets formatted in accordance with a file format for spatial audio includes asset metadata that enables simulated reality (SR) application developers to compose sounds for use in SR applications. The audio assets are formatted to include audio data encoding a sound capable of being composed into a SR application along with asset metadata describing not only how the sound was encoded, but also how a listener in SR environment experiences the sound. A SR developer platform is configured so that developers can compose sound for SR objects using audio assets stored in the audio library, including editing the asset metadata to include transformation parameters that support dynamic transformation of the asset metadata in the SR environment to alter how the SR listener experiences the composed sound. Other embodiments are also described and claimed.