9.1.8 Long term preservation of digital audio objects  It is quite common that, when commencing digital preservation, the costs of long term storage of digital audio objects are permanently and persistently underestimated. At the time of writing professional storage costs are considered to be in the order of a minimum of $US 5/GB/year2 for medium to large scale storage (over 5 TB) Although the hardware cost price has been permanently declining, the cost of the management of the storage, the continuous migration to new generation storage, the hosting in adequate premises (clean room, etc) are always underestimated. As a political target UNESCO has challenged the IT industry to arrive at $US 1/GB/year in the short term, a target which seems far from being met. Some figures detailed in a PrestoSpace study show a trend to stabilize long term storage costs at $US 9/GB/year. As digital audio objects on an average require 2 GB/hour, even future lower preservation costs will still be too high for many cultural institutions.  Lower digital storage costs can only be achieved for smaller quantities if the labour costs involved in small scale manual approaches are not incorporated. The systematic use of open source software may make autonomous, not fully automated processes viable in near future also for medium amounts (10-20TB) of storage requirements. The involvement of specialised staff to guarantee the permanent availability of archival files in manual or semi-automatic operation must not be underestimated.  Some service providers have recently developed adequate outsourced preservation strategies based on the mutualisation of the use of professional large scale mass storage systems with specific access schemes to users. Their fee is usually based on the size of the digital archives to be stored, the duration of the contract, and the associated services. For small and medium scale archives it can be an attractive solution, as well as for large scale archives before deciding to invest in their own storage solution.

2. Despite the current difference in monetary value USD and EURO are approximately same in the IT world