A method of audio processing comprises composing one or more transformation profiles for transforming audio characteristics of an audio recording and then generating for the or each transformation profile, a metadata set comprising transformation profile data and location data indicative of where in the recording the transformation profile data is to be applied; the or each metadata set is then stored in association with the corresponding recording. A corresponding method of audio reproduction comprises reading a recording and a meta-data set associated with that recording from storage, applying transformations to the recording data in accordance with the metadata set transformation profile; and then outputting the transformed recording.