# Reading Tapes Backwards: A Legitimate Approach to Saving Time and Money in Digitization Projects? [PERSON]  
1 Department of Art, Stony Brook University, New York, NY 11794, USA 1+  
Chinatapes (e.g., Figure 1(a)), where all the tracks are meant to be read in the same direction, most tapes will show two sides (e.g., standard track configuration in Figure 1(b), non-standard track configuration in Figure 1(c)). The playback equipment must be compatible with the tracks on the tape. For example, Figure 0(b) shows the detail of double stereo tape heads. These heads are compatible with double stereo tapes (Figure 1(b)). When we work with a digital signal, a number of signal manipulations become possible-whether the signal was _digitised_ (analog-to-digital transfer) or whether it was extracted from a digital carrier and transferred to a digital workstation (digital-to-digital transfer). Easy manipulations include normalization, equalization, trimming, or the reversal of a full track. In this article, we focus on the last one, that is, reversing a signal head to tail, equivalent to reading it \"backwards\" (Figure 3). From the possibility of reverting a digital track like this derives the fact that we could extract all tracks on a two-sided tape in one pass, regardless of the intended direction, since we can subsequently reverse the signal in our workstation. This is an interesting option, because the total digitization time for each tape is reduced by 50%. In small and, especially, in large digitization projects, this means hundreds of hours saved--which also means money saved. Audio preservation is \"a costly and time-consuming affair\" ([PERSON] and others, 2018) with highly repetitive routines ([PERSON] and others, 2018), and \"reading (some tracks on) a tape backwards\" is a practical solution that one time or another has occurred to anyone involved in a digitization project. For a fact, a number of projects have resorted to this 'trick' to save time. The question is: does this solution alter the audio signal? Is the signal extracted in the orthodox way equivalent to that extracted \"backwards\" and then reversed? How do we define 'equivalent'? The ultimate open question is whether this time-saving procedure is compatible with a sound methodological approach to audio preservation, both from a theoretical and empirical point of view. In order to start answering this question, this article presents a data set that was built and studied to understand whether it is possible to define and measure the differences between audio signals extracted from a magnetic tape in the intended direction or 'backwards.' In particular, we present an experiment where seven different signals were digitized five times forward and five times backwards each. The digitized signals were analyzed to detect significant variations. Figure 1: Audio equipment (**left**) and close-up of tape heads (**right**). Figure 2: Examples of standard and non-standard track configurations on one- and two-sided tapes. Source: [PERSON] and [PERSON] ([PERSON] and [PERSON] (2018). The value of this work lies in that:  
* it identifies an effective feature to measure the variations between different digitizations;
* it is the first systematic study of the question of whether reading tapes backwards is a legitimate strategy in the context of digitization projects;
* the complete data set is open and accessible, as well as the Matlab algorithms used for the data analysis (available on Zenodo at: doi.org/10.5281/zenodo.4430360; accessed on 20 June 2021). This study contributes to the long-term goal of building a structured body of knowledge on magnetic tapes in the context of their preservation. Knowledge can be expressed in the form of scientific literature [2; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20] and applications [21; 22; 23; 24] to (i) contribute to the normalisation of audio preservation practices and (ii) to support the systematic accumulation of existing and new knowledge, accelerating its capitalization.