REVIEW OF EARLY STORAGE MEDIA DEGRADATION FACTORS, PRESERVATION TECHNIQUES AND TRENDS IN ETHIOPIA Bisrat Derebssa Dufera School of Electrical and Computer Engineering, Addis Ababa Institute of Technology, Addis Ababa University [email protected] ABSTRACT Since the invention of the Gramophone by played back in 1877 by recording human Thomas Edison in 1877 society has used voice on a tinfoil wrapped around a different storage media to record and store cylinder. Since then recorded sound has sound as important aspect of human life. been an important aspect of human life. Continued preservation of these data for the Now music can be heard at home privately generation to come has been regarded as and it became possible to hear the same important goal of archivist and libraries. However, since analog storage media are not “performance” multiple times. With the permanent, these storage media are under risk invention of sound recording, educators of degradation and damage. As a result, several could bring sound recordings in classroom preservation techniques and guidelines have to aid the teaching-learning process. been prepared and applied to prolong the Another important aspect of recorded sound shelve life of these analog storage media. These is the preservation of oral culture. Folklore preservation techniques slow down the rate of and ethnographic collections “provide audio degradation; they do not stop or reverse it. As a windows into a range of cultures and result, the long-term solution is the digitization geographical areas. Perhaps no other sound of these recordings and copying them into the medium has conveyed to listeners so much newest format whenever there is a format history and culture, through music, diverse change. A review of degradation factors affecting storage media, preservation entertainment programming, daily news and techniques, digital preservation guidelines and public affairs, and interviews” [1]. current preservation techniques employed in A survey conducted by Heritage Ethiopia are presented in this paper. From the Preservation Inc. in partnership with the review, it has been observed that even though U.S. Institute of Museum and Library there are some institutions in Ethiopia that have Services of public institutions estimated that understood the problem of degradation and have taken actions to decrease its effect, some there are around 46 million individual institutions have not taken proper analog and recordings in these institutions of which digital preservation actions. As a result, the 44% of audio collections in their library statuses of their archives are not known and were in “unknown condition” [1]. The significant portions of their archives are Music Archive of the Ethnological Museum expected to be degraded. (Germany) houses 354-cylinder collections with approximately 16,800 recordings on Keywords: Early sound recordings, wax slightly over 30,000 cylinders and cylinder, graphophone disc, magnetic tape, approximately 3,500 magnetic tapes. Ethiopian broadcasting corporation, Institute of Ethiopian Studies The condition of the recordings is not well known [2]. The British Library estimates INTRODUCTION that of the 6.5 million sound recordings in Thomas Edison was the first that successfully recorded sound that could be 27 Bisrat Derebssa its archive, 1 million of them are in risk of permanent media. Tasks that need to be disappearing [3]. taken by libraries and archivists are preservation, digitization, and restoration According to [4], the history of electronic [5]. media in Ethiopia starts with the first provisional radio station in 1933 by an Even though the long-term solution to these Italian Company. To the author‟s set of problems is digitizing the archives knowledge, the most important audio-visual and storing it in the latest format, most libraries in Ethiopia are the Ethiopian estimates agree that institutions have only a Broadcasting Corporation (EBC) audio- small window of time in which to complete video library, National Library of Ethiopia, high-quality digitization depending on and the Institute of Ethiopian Studies (IES) storage conditions, the storage media used library of Addis Ababa University. It is and other factors [6]. difficult literature on the status to obtain To get a clear picture of the problem facing of storage media in these Ethiopian audio- these storage media in Ethiopia, literature video Libraries. This may stem from lack of review and library survey were conducted. understanding of the risks facing storage The literature review and library survey media, lack of funding or lack of when presented together are hoped to shed experienced staff that can undertake the task light on the current Ethiopian audio-video of preservation. archive risks in a single setting. These audio recordings are stored in LITERATURE REVIEW different audio libraries and museums in different parts of the world. Several types of The literature review focuses on research storage media have been used according to that was conducted worldwide related to advances in technology and demands of the storage media degradation, analog market. A brief chronology of recorded preservation and digital preservation. Its formats commonly found in libraries, sound aim is to review degradation factors for archives and private collections is as each storage media and state of the art follows [1]. preservation techniques. It will be used to assess the progress done in Ethiopia. 1889: Wax Cylinder 1893: Flat disc Library Survey: In the library survey, 1902: Black-Wax Cylinder audio-video libraries in Ethiopia were 1940: Wire magnetic recorders surveyed to assess the status of the stored 1948: Magnetic tape media and preservation techniques 1948: Flat Discs of PVC employed. Oral interviews and library visits were conducted to assess the libraries. The 1958: Stereophonic LP discs results of these observations are then 1964: Compact Cassette tape compared to the degradation factors and 1982: Digital recorded compact state of the art preservation techniques that discs are obtained in the literature review. 1990: Recordable compact disc The literature review showed the significant The stored data in these storage media is risk of archived media. Even though the faced with two important and unavoidable library survey conducted is only done in problems: deterioration due to „natural two institutions, by analyzing its findings aging and improper storage environment‟, from the literature review it showed status and format obsolescence. Therefore, of the two possible extremes of audiovisual libraries and archivists are faced with the libraries on efforts made to preserve the task of copying these contents into a more data stored in the storage media. Journal of EEA, Vol. 37, May 2019 28 Review of Early Storage Media Degradation Factors, Preservation Techniques… The paper has been organized in five moving the membrane. The vibrations are sections as follows. Section 1 briefly then amplified by the horn. discusses the problem and methodology to be used. Section 2 discusses the storage Cylinders may be divided into the following media that have been used in the past types and their degradation is also affected century from the point of view of their to a different degree. principle of operation and degradation Brown-Wax Cylinders factors. Section 3 discusses the different preservation techniques that have been used Brown wax is a "metallic soap," combined and applied for the different storage media. with natural waxes. This material is soft Section 4 discuss the findings of assessment enough to make a direct recording [10]. of EBC library and IES library on the status Playback of any wax cylinders at a of archived media in Ethiopia. Finally, temperature exceeding 25°C should be Section 5 concludes the paper by briefly absolutely avoided as wear may increase discussing the implication of each of the significantly with temperature [10]. In chapter and stating what needs to be done in addition, rapid temperature changes may the future and the current state of archived cause hairline cracks and total loss of a media in Ethiopia. record [10]. Because of their highly organic composition, they are unfortunately prone Storage Media Employed to fungus attack. Humidity and temperature Of the different media that have been used, significantly increase the rate of fungus the cylinder, flat disc, magnetic tape and infection. Often, they are found in an compact disc have the most of historical, unplayable condition because of this fungus cultural, entertainment and other data [1]. damage [10]. This is expected to be the case for Black-Wax Cylinders audiovisual media stored in Ethiopian libraries and archives. Of these, the compact Black-Wax cylinders are made from metal disc is the most recent and stable. A recent soaps (lead stearate) with carbon and study on accelerated aging test of compact additional hardening agents [10]. The main disc has reported the average life advantage of black-wax cylinders over expectancy of the compact disc under room brown-wax cylinder is that they can be mass temperature and controlled humidity to be produced by molding process [11]. Another 776 years [7]. Therefore, only the cylinder, advantage is that black-wax records can be flat disc and magnetic tape are considered played at higher speed than most brown- under significant risk and this review wax records. Therefore, they are louder and focuses only on these storage media. capable of better sound quality [10]. Black- wax cylinder is more brittle, and becomes Phonograph Cylinder more so with age as compared to brown- Phonograph cylinders, classified as a wax cylinder. Similar to brown-wax mechanical carrier, are the earliest cylinder they are prone to microorganism commercial medium used for recording and damage. reproducing sound [8]. Sound, which is a Celluloid Cylinders function of air pressure variation was captured by a horn that moves a membrane Celluloid Cylinders were made from plaster which was connected to a cutting stylus [9]. core with celluloid plastic playback surface The stylus then carves these movements layer. Some of the advantages of celluloid into the surface of a rotating cylinder.