The shift of the archivist focus from supports to contents involves the shift to an active style of conservation. Since the end of the Twentieth Century, the classic paradigm ha moved from preserving the master copy to “to distributing means to conserve”. The statement means that it is paramount to digitize audio information and make it available through digital libraries technologies. The transfer of audio information to the digital domain (potentially) allows higher resistance to ageing. Besides, it allows a more effective content research based on queries by humming (melodies whistled by the user) or on queries by example (audio examples taken from different audio files). In order to guarantee its conservation, audio information should be restored operating on (digital) copies that perfectly correspond to the master copy.
This procedure allows to decide which restoration approach should be adopted every time we come across an audio artefact. It is not rare to have different audio interpretations for the same master copy depending on the chosen listening settings, which may vary from concert rooms (for example, in case of an opera for magnetic tape and acoustic instrument), to domestic environment (personal computer loudspeakers, one- or two-channels high-fidelity systems), or to mobile applications (digital files or car players).