1. IST 653 Digital Libraries

2.  Communal  Media based (records/tapes)  Expensive to produce ◦ Audio production required a lot of expensive and difficult to maintain equipment  Expensive to listen ◦ Recordings were expensive & costly to maintain ◦ High fragility

3.  Listening habits have changed ◦ Based on individual tastes and lifestyle  Playback devices have changed ◦ Cheap and abundant  Users expect easy access  Downloading more common  Mom & Dad used to run the home stereo, now it’s the kids’ domain  Podcasting

4.  Equipment of yesteryear does not align with people’s expectations  Patrons and researchers often expect to “do” something with your content  Video and audio production no longer for the expert or the rich only  It’s cheap to create audio and video  It’s relatively easy to produce and edit  Everyone wants to produce audio and video

5. 1--Preserve and extend the life of your archival holdings 2--Improve control—once you digitize, you will know your collections better 3--Improve access—patrons then can access your collection over the web 4--Expand your reach—through the web, you will reach users not Reasons to Digitize

6.  Minimize use of fragile and aging collection  Costly maintenance of analog equipment  Analog equipment does not meet expectations of current users on multiple levels

7. Playback Storage/Access Digital Conversion Workstation

10. Less bandwidth required for web access Smaller file sizes compared to video Analog formats much simpler Less complex format to understand than video

11.  Tape recording, as we know it, began in the 1940s  Well understood format  Analog tape used into the 1990s  Digital Audio Tape (DAT) used through 1990s and 2000s  Mini Disc (not tape) used through 1990s  Magnetic tape still in wide use as backup for data storage centers  Considered a legacy format by broadcasters and audio engineers

13.  In high use up through the 1990s  Broadcast quality sound  Typical in radio stations and recording studios  Available in different tape widths ◦ ¼” tape -> 2” tape  Play at different speeds  Differing tape speeds or IPS (Inches Per Second)  15/32 IPS  120 IPS  The faster the speed, the better the quality

14.  Easy to play and record  Common consumer format, some broadcast  1/8 inch thick  Come in variety of lengths ◦ 45 min,60 min, 90 min, and 120 minutes  Longer the tape, the thinner it is (less quality)  All play at 30 IPS (inches per second)

15.  Surveys are useful for large collections  Not necessary for small collections  Cataloging / processing the analog collection can speed up digitization process  Helps prioritize your digitization projects  Good information when applying for grants  Software tools to assist survey process  FACET (The Field Audio Collection Evaluation Tool ) NYU and Columbia  Unique problems with audio and moving images

16.  Magnetic deterioration ◦ “Print Through”  Chemical deterioration ◦ “Sticky Shed” Syndrome ◦ Vinegar syndrome

17. Thinner tapes (designed for longer running times, since more tape can be held on the same spool) are more prone to the effect than thicker tapes, and tapes held in storage for a long period or exposed to a weak magnetic field can show pronounced print-through.” Source: http://en.wikipedia.org/wiki/Print- through

18. “Sticky-shed syndrome is a condition created by the deterioration of the binders in a magnetic tape, which hold the iron oxide magnetizable coating to its plastic carrier.

20. “Tape baking is a process that is used to restore magnetic tapes: audio cassettes and video tapes that have begun to go through a chemical breakdown due to age, known informally as shedding. It cannot be used with acetate tapes.” Source: http://en.wikipedia.org/wiki/Tape_baking

23.  For Reel to Reel players, there is always a correct speed to for playback  The speed is indicated in IPS or Inches Per Second  71/2 IPS is the most popular, but range from15/32 IPS to 120 IPS  The faster the speed, the better quality the audio is Tape Speed

26. Record Tabs

28.  Become familiar with your equipment  Pop record tabs from tape  Rewind to the beginning of tape  Make sure all settings are correct on deck  Demagnetize the play heads using a “Head Demagnetizer”  Clean the play head with alcohol

29. Close-up of Cassette Deck

30.  Disconnect machine before cleaning!  Conduct before engaging in a large project  Use wooden stick cotton swabs  Use isopropyl alcohol  Clean guides and capstan  Consult with expert before trying on your own  Parts/heads get inadvertently magnetize

31.  Sometimes your donor may have a playback device, ensure it’s in good working order  Craigslist or ebay are options  Purchase new (still in production) ◦ Cassette Deck ◦ Turntables ◦ Reel to reel  Be patient, opportunities arise for “free” equipment

32. Mini Stereo RCA Left and Right ¼” Left & Right Mini Stereo to ¼” Stereo Female RCA to Stereo Mini XLR Female to Male

33.  Avoid using mixing boards or equalization  AKA adding a “curve”  Equalization makes sound sound better  But, adds extra sound not found in original  The user can always equalize later on

34. Playback Storage/Access Digital Conversion Workstation

35.  Analog to Digital Conversion box  AKA a “Break out box”  Digitizes audio and sends data to PC  Typically better audio  More options  Can be more expensive  USB or Firewire driven

36.  AKA “Redbook” Audio  Developed by Sony and Philips  Compact Disc introduced in 1980  By early 1990s, standard audio format  Finally, one format for music!  Needed to be portable (cassette size)  Needed to fit into LP display racks  Could not be copied! (for almost a decade)

37.  Encoding rate was a compromise between form factor, sound quality and playing length  79.8 Minutes (purportedly the time length was based on Beethoven’s 9 th Symphony)  Encoded at 44.1Khz sampling rate and 16 bit rate  Encoding rate better than human hearing!  We will talk more about bit depth and sampling rates soon

38.  Open standards preferred  Proprietary standards not as desirable, but can offer features not available in open standards (Flash vs mp3) (Word vs. PDF)  Master files should be high resolution  Access files should be lower resolution  The resolution of audio is determined by its sampling rate and bit depth

39.  Important to understand  Some suited for preservation copies  Some suited for access or use copies  Some open and proprietary  Most have long histories spanning the life of many computer systems and software  Type of format is indicated by the extension (i.e.,.wav,.mp3,.aiff)

40.  Long history of use back to 1970s  Used in LaserDisc digital video format 1978  Lossless or un-compressed file format  Most common un-compressed audio format  PCM is always “contained” by another file format  Typical containers are AIFF and WAV  Preferred archival format

41.  Allows us to shrink file size without noticeable difference in quality  Commonly used over the web  Mp3, AAC are common formats  Used in iPods and other portable audio devices  An algorithm compresses the sound so that it is indistinguishable to the human mind  Not “preservation” quality  Data loss will occur with each new migration of the audio file

42.  AKA Microsoft WAVE  Most common container for PCM audio  Very popular  Developed in 1991  Limited to 4 Gigabytes  Has been extended by BWF (Broadcast WaveFormat) which allows additional metadata insertion into header  Most common master file format for audio

43.  Both are technical terms that can be difficult to understand  Both terms are brought up routinely in discussions about audio digitization  It is important to have at least a cursory understanding of them  Your choices about which rate to use will have implications for providing storage and access to you collections  I will slowly walk you through both of them Sampling and Bit Depth Rates

44.  The sample rate is the number of times your audio is measured (sampled) per second. So at the red book standard for CDs, the sample rate is 44.1 kHz or 44,100 slices a second. The higher the sample rate, the better quality audio you will capture.

45. Samples or “pictures” of audio

46.  Bit Depth refers to the size of the sample. 16 bit audio is what is used for Compact Disc audio, there are 65,536 possible levels of detail. With every bit of greater resolution, the number of levels double. With 24 bit, we actually have 16,777,216 levels of detail. Remember we are talking about a slice of audio frozen in a single moment of time.

47. 8 Bit 4 Bit 2 Bit 1 Bit

48. Sampling Rate 44.1, 48, 96 khz Time 16 Bit 24 Bit

49.  Pick encoding rates based on need and type of material and planned use  Spoken audio typically uses 24 bit depth and 48khz sampling rate  Music is 24 bit depth and 96 khz sampling rate  CD quality is OK too, 16 bit and 44.1 khz  Both use WAV file format

50.  MP3 is a popular access file format  It is the “JPEG” of the audio world  MP3 compresses sound in such a way that the human cannot easily distinguish  If there are two sounds playing simultaneously, we hear the louder one but often cannot hear the softer one

51.  So if Compact Disc is already recorded at sampling rates beyond what the human can hear, why are do we over-sample?  Over-sampling will aid future archivists during migration from one format to the next  It’s an insurance policy against “data rot”

52. Playback Storage/Access Workstation Digital Conversion

53.  There are many brands to choose from  Some are either PC or Mac only, some both  Audacity is one the few free editors available  Proprietary often has features not found in free software, ease of use and stability  We will use Audacity for today’s workshop

57.  BTW, always keep the originals!  Store them in a climate control environment  Digitizing is not an effective technique for making more shelf space Analog Tape Storage

58.  Audio files sizes can be big  Give serious consideration to your long term storage needs  The more “archival” the reformatting project is, the more storage will be a concern  How you provide access may determine storage solution  Good metadata is integral to successful long- term storage plans  Are you digitizing for access or preservation, both?

59. Number of tracks and length 16-bit at 44.1 kHz 16-bit at 48 kHz 24-bit at 44.1 kHz 24-bit at 48 kHz 16-bit at 88.2 kHz 16-bit at 96 kHz 24-bit at 88.2 kHz 24-bit at 96 kHz 1 mono track 1 minute 5 MB5.5 MB7.5 MB8.2 MB10 MB11 MB15 MB16.4 MB 1 stereo track 5 minute 50 MB55 MB75 MB83 MB100 MB110 MB150 MB164 MB 1 stereo track 60 minutes 600 MB662 MB900 MB991 MB1.2 GB1.3 GB1.8 GB2 GB 32 mono tracks 5 minutes 800 MB883 MB1.2 GB1.4 GB1.6 GB1.8 GB2.4 GB2.8 GB 32 mono tracks 60 minutes 9.4 GB10.4 GB14 GB15.5 GB18.8 GB20.8 GB28 GB31 GB Spoken WordMusic 1 Hour http://www.dlib.org/dlib/may07/weig/05weig.html

60.  Optical Media Storage ◦ DVDs, Gold CDs, and Audio “Red Book” CDs  Local hard drives ◦ Computer based or external drives (Firewire/USB)  Both of the above options will work, but they are not preferable for big and long term solutions for data storage

61.  Networked Servers ◦ Common in all medium sized organization ◦ I f you have a website, you have access to networked servers ◦ Preferred option for long term storage  LTO Data tapes ◦ Popular with banks and records management  Digital Asset Management System (DAMS) ◦ Depending, a DAMS can provide both access and preservation

62.  Vendor may be more practical option ◦ Granting agencies may prefer it ◦ Fragile material demanding special equipment or expertise ◦ Vendors are used by small and large institutions  For small collections, may not be worth it ◦ Learning the basics not a huge investment ◦ Just getting feet wet in audio reformatting