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 to preserve the master copy has shifted to “to distribute means to conserve”, which means that it is necessary to digitize audio information and make it available through the digital libraries technologies. The transfer of audio information in the digital domain (potentially) allows higher resistance to ageing, and besides allows a more effective contents 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 provide to its conservation, audio information should be restored by operating on (digital) copies obtained by the ones that perfectly correspond to the master copy.
This way of proceeding allows to decide each time which restoration approach should be adopted. In fact it is not rare to have different audio interpretations for the same master copy, depending on the chosen listening setting, 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 situations (digital files players, car audio players).