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Digital Talking Books -- Planning for the Future

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Ce texte est tiré des actes du Colloque international sur les nouvelles technologies du livre adapté (1er : 1997 : Salon du livre de Montréal). Vers une nouvelle génération de livres pour les personnes aveugles : [textes des conférenciers] / Premier colloque international sur les nouvelles technologies du livre adapté ; Institut Nazareth et Louis-Braille en collab. avec le Forum des pays francophones de l'Union Mondiale des Aveugles. -- Longueuil : Institut Nazareth et Louis-Braille ; Longueuil : Union mondiale des aveugles, Forum des pays francophones, 1998.

Micheal M. Moodie
Research and Development Officer
National Library Service for the Blind and Physically Handicapped.
Library of Congress



Today the rapid pace of technological change impacts all of our lives profoundly, forcing us to change the way we think and act and see the world. This is equally true in the domain of library service to print-handicapped people. The incredible advances in computing and communications are making possible tools and techniques for blind and physically handicapped people to access information that were unthinkable just a few years ago. But the pace of change and the bewildering array of possible technological solutions make it difficult for agencies serving print-disabled people to know what course to chart. We at the National Library Service for the Blind and Physically Handicapped (NLS for short) are continually weighing these uncertainties, trying to see the most promising path to the digital future.

Today I will cover five areas:

  1. Describe NLS -- who we are and what we do.
  2. Discuss some key factors that influence our thinking as we look toward the future.
  3. Discuss the process we will follow in planning for and implementing the transition from an analog to a digital audio system.
  4. Explain why we are moving into the digital world more slowly than some other agencies.
  5. Describe one possible future delivery system for digital talking books that we see as attractive.

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1. The National Library Service for the Blind and Physically Handicapped

NLS was established by Act of Congress in 1931 as a section of the Library of Congress. We are funded by the federal government with an annual budget of about $46 000 000.

Our primary goal is to serve as a public library for Americans who, because of a visual or physical disability, cannot use standard print materials. The books we produce are split evenly between fiction and non-fiction and cover the wide range of topics you would expect to find in a medium-sized public library.

We produce about 2 000 books each year -- 1 700 on 4-track, 15/16 inches per second cassettes and 300 in braille. In addition, we make available 45 recorded magazines and 33 braille magazines, including such popular titles as National Geographic, Sports Illustrated, and Consumer Reports. The audio magazines are now produced on flexible disc, a thin, vinyl phonograph record, but starting next January, we will begin the process of moving them to cassette over the next few years.

NLS is only one half of a partnership that provides library service to print-handicapped Americans. The other half is a network of 143 libraries spread across the country. 56 of these, called regional libraries, cover all or part of one of the fifty states.

Most regional libraries are administered by their state library.

Each of the 87 subregional libraries works under the direction of a regional library and serves a smaller geographic area, usually out of a public library setting.

So this partnership between NLS and the network libraries represents a cooperative effort between federal, state, and local governments. NLS selects and produces the books, magazines, and playback machines and drop ships them to the network libraries. The libraries in turn circulate them to patrons. So each member of the partnership contributes what it is best-suited to provide: NLS provides national coordination to the effort and manufactures items centrally to gain economies of scale. Network libraries, on the other hand, are closer to their patrons and better able to provide personal service. NLS also operates two multistate centers, one in the eastern U.S. and one in the west, that serve as warehouses storing backup copies of books, magazines, catalogs, and playback equipment for the libraries.

Out of an estimated three million eligible Americans, NLS serves a combined readership of 776 000 Americans.

Of these, 586 000 use cassettes, 161 000 use discs, and 28 000 use braille. As mentioned earlier, books are loaned to readers by network libraries.

Magazines are set up on a subscription basis and mailed directly to subscribers from the manufacturer. Last year, NLS and its network circulated approximately 23 000 000 braille and audio books and magazines, sending items postage-free via "Free Matter for the Blind and Handicapped."

Readers learn of newly released books through two bimonthly publications -- Talking Book Topics, issued in large print, on flexible disc, on cassette, and on floppy disc; and Braille Book Review, published in large print, braille, and on floppy disc. Both publications are also posted on the NLS web site. In addition, NLS maintains a union catalog listing its holdings as well as those of the CNIB, Recording for the Blind and Dyslexic, and several other libraries for the blind. The catalog is available on CD-ROM and online.

NLS designs and contracts for the manufacture of playback equipment that is loaned to readers. We currently offer four different types of machine. The workhorse of the program is the basic cassette player, which can play both 15/16 4-track as well as commercial speed cassettes. This unit is designed for longevity and repairability. 40 percent of our current inventory of these machines are more than ten years old. Ten percent are approaching twenty years of age.

The second model also plays cassettes, but was designed for use by patrons who found the standard player too complicated. It contains an auto-reverse deck so that the patron can play all four tracks without handling the cassette. The other two playback machines provided by NLS are record players, which are being used less each year as discs are phased out. Our current inventory of equipment comprises approximately 672 000 cassette players and about 140 000 disc players.

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2. Key Factors in Design of NLS System

What follows is a list of the elements that drive the design of the NLS program and affect any changes that are considered.

We offer a free library service. Just as sighted Americans can use their public library at no cost, so we do not charge for use of the NLS program. If playback equipment is required to use the program, we will supply it so readers can participate regardless of income.

We are consumer-driven. NLS involves representatives of blindness organizations and network libraries in deliberations leading to all major program decisions. We believe consumer involvement is critical to maintaining an effective and responsive library service.

No royalties are paid to copyright holders, but in return recorded books and magazines must be limited to eligible users. A recent amendment to the copyright law allows authorized agencies to create special-format versions of copyrighted works without first requesting permission.

The program must be accessible by a wide variety of users -- from mildly visually impaired to totally blind, from children to the elderly (the majority of patrons are above 65), from active readers to passive ones, and from the physically able to the severely disabled/multiply handicapped.

The primary focus of the program is on the recreational and informational reading needs of patrons. That is, as mentioned above, we are in effect a public library. We are not focussed as much on the needs of students and professionals.

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3. Planning for Transition to a Digital System

NLS has made three assumptions in planning for the next-generation talking book system.

  1. Next system will be digitally-based.

    One reason for this is that analog systems are simply declining in use.

    The other is that digital systems offers a number of advantages over analog systems:

    • Potential for improved sound quality (This is useful, but not essential for spoken word recording)
    • Potentially, the ability to listen to an entire book without manipulatin the medium (for exemple, changing records, turning cassettes over)
    • Enhanced navigational capabilities (The ability to jump from the table of contents to a chapter, skip through text a paragraph at a time instantly, choose to read or skip oer footnotes, etc.)
    • Ability to include the text of the book along with the recorded version (This allows the spelling of words, keyword seraches of text, etc.)

    I could go on at length, but George and Stephen both are more conversant with these capabilities and much further along toward a realization of them, so I will let them expand on this topic.

  2. Our second assumption is that the current 4-track 15/16 ips cassette system will carry us at least another five to ten years. Eventually, we expect that a declining market for cassettes will lead to increased costs for cassettes, playback unit components, duplication equipment and supplies, and so forth. Simultaneously, the cost of digital system components will be dropping. But we don't expect significant cost advantages for digital applications in our system for at least five to ten years.
  3. Our final assumption is that we must use a standard or slightly-modified version of a widely-used consumer product or technology to gain the cost benefits of economies of scale. We simply don't have a large enough market or sufficient research dollars to pursue a technology that is out of the mainstream.

Given these assumptions, how do we get from where we are to where we want to be? What follows is a partial list of the tasks that must be performed in the design and implementation of a next-generation talking book system. This is a complex undertaking. While NLS has gone through one earlier change in delivery media, from phonograph records to cassettes, only the medium, its mailing container, and its playback device were replaced. Otherwise, the system stayed the same. Now we are planning a change that will certainly affect many and may affect every aspect of our talking book system, from recording through distribution. Very little of what we see today in our system will remain unchanged. We should not underestimate the complexity or difficulty of this undertaking.

Task 1: Define and prioritize digital talking book (DTB) features.

The starting point in the design process should be the user. They must define what it is they want in the next generation of talking books. NLS has begun this process, in conjunction with CNIB, Recording for the Blind and Dyslexic, The DAISY (Digital Audio Information System) Consortium, and many other groups, working under the auspices of NISO, the National Information Standards Organization. NISO is an accredited standards-creating body in the United States.

Members of the NISO committee on digital talking books have met twice this year and will convene again next March. Outcomes of this effort will include a standard describing the file specification for a digital talking book. This standard will ensure that agencies recording talking books in accordance with the file specification will be able to read each others' books on standards-compliant playback equipment.

Other products of the NISO process will include technical reports that list and prioritize the desired features in digital talking books and talking book players and describe the production steps necessary to implement the book features . Draft standards and technical reports are due in November, 1998, with final versions following perhaps a year after that.

Task 2: Simulate a digital talking book using a personal computer.

This step will allow NLS to test patron interest in different features and experiment with various ways of implementing them, before proceeding too far in the development process. By linking easily modifiable control panels to the PC, we will also be able to test different user interfaces. In order to control risk, we propose to build several simulations based on different software approaches.

Task 3: Develop a computer-based life-cycle cost analysis tool for the NLS system and candidate digital systems.

We see this tool as critical to assessing the economic viability of different DTB options. Because a talking book program is a complex organism with many interrelated parts, one must look at the whole system when making cost comparisons.

We plan to develop a spreadsheet-based cost model that will allow us to easily compare different approaches or combinations of approaches. Feeding into the model will be historical costs from our current system as well as cost projections based on forecasts of long-term trends.

Task 4: Design or select a digital mastering system.

Based on the results of the NISO process, NLS will design, or, if a suitable system is available, select, a digital recording system capable of implementing the features identified by NISO participants. While most of NLS's books are recorded in professional studios under contract, many books and magazines produced by our network libraries are done in small studios with very limited budgets. NLS will need to ensure that these studios have available the tools they need to work in the digital domain. A parallel effort will develop the tools necessary to convert existing analog recordings to NISO-compliant digital files.

Task 5: Design and build a prototype digital collection access and archiving system.

This component is the heart of the DTB system. It will contain the entire digitized content of our talking book holdings, which we estimate at about 140 terabytes of data. It must contain facilities for long-term archiving as well as supplying DTB files for production, if we choose to use a physical medium, or distribution, if we opt to disseminate audio books via a telecommunications channel.

Task 6: Select an acceptable copyright protection system.

As mentioned earlier, U.S. copyright law requires that NLS limit access to its materials to eligible users.

Authors and publishers are concerned that our books and magazines will spread to the sighted community, possibly damaging the market for print or commercial audio materials. Once we enter the digital domain, this becomes increasingly possible, so we need to build in adequate safeguards.

Task 7: Identify a suitable delivery system, based on technological assessments, input from users, and the cost model described earlier.

This is the riskiest task of the lot. It will be based in large part on projecting the future of technology, which is notoriously difficult. If a physical medium is chosen, such as CD-ROM or DVD, then production processes must be identified, labels designed, and mailing containers developed. If a telecommunications-based solution is selected, then systems must be designed to support the transfer of digital files to the reader.

Task 8: Select or design playback equipment that supports the features in the NISO DTB standard.

One of the challenges facing us is how to build in the features desired by more sophisticated readers without making a player too complicated for those who are less technically adept and who make up the majority of our users.

One solution proposed by the NISO committee is to develop two different players -- a basic unit with a limited number of features, and a more advanced player with the full range of NISO features.

The tasks discussed above represent only a brief overview, of course, of the process of moving to a digitally-based talking book system.

Although they are listed sequentially, many will, in fact, proceed in parallel. We are watching with interest the work of the DAISY Consortium which is grappling with all of the issues I have just discussed. We have a representative on their technical subcommittee and, as I mentioned above, they are participating in the NISO process.

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4. Why Ten Years to the NLS Digital Talking Book?

Earlier, we discussed a few of the benefits a digital talking book will bring to readers. While several, such as improved sound quality and decreased manipulation of the playback media will be useful to all patrons, they are marginal improvements that do not by themselves justify a major change. The most significant of the benefits, such as enhanced navigation and text-related features, will accrue primarily to the more sophisticated users and the more complex books, that is, students reading textbooks. While NLS does have a subset of users and a certain number of books that will gain from the use of a digital system, the majority of patrons and books will see only moderate improvements. For this reason, NLS is less motivated to change in the near future than are other agencies that primarily serve students -- the major beneficiaries of DTB technology.

Further, we are not currently aware of a medium or a delivery system that is low enough in cost or offers enough advantages over our current system to justify a change. As an example, let me discuss the applicability of a CD-ROM-based delivery system to our program, as it is the most viable current option.

First, we see the costs of a CD-ROM system as roughly comparable to our current cassette system, so there are no significant cost savings that would motivate a change. The last time we began a transition from one medium to another, in the early seventies, our budgets were expanding every year so it was easy to finance the parallel production of old and new playback machines . Now NLS finds itself facing years of level or only marginally growing budgets. So it is our hope that whatever digital system we select will offer enough savings to at least partially finance the transition. Change will be extremely difficult otherwise.

Second, we are concerned with the longevity of the CD-ROM. By this, I do not mean the lifespan of a CD-ROM disc, but rather the expected life of the technology itself. How long will CD-ROMs be a viable medium? Already, DVD is waiting in the wings. NLS has an enormous investment in machine and media inventory -- nearly a million cassette and disc players and over fifteen million copies of audio books . It takes a long time to change over that inventory. We introduced cassettes in the early 1970s and it took over fifteen years before we stopped producing books on rigid disc. We are still transferring titles from disc to cassette format nearly thirty years later. Given the shorter and shorter life spans of electronic technologies, we wonder how many years we could make use of CD-ROMs before we were forced to begin the transition to yet another medium (especially if we don't begin to use them for another five years or more). Because of our enormous inventory, we need to adopt a technology early in its life so that we can utilize it for the maximum number of years.

Most of the libraries in the NLS network record and duplicate materials locally using volunteers.

This entire network of volunteer agencies must be able to use the technology we migrate to. They contribute a significant number of books every year to the collection, and record many magazines locally. So we have to consider the expense and complexity for these groups as they move to the new technology and ensure that it will be an enduring one -- so they do not have to replace all their equipment in a few years.

Third, we are very uncertain about the costs of maintaining CD-ROM players. As I mentioned earlier, the vast majority of our books and machines are sent to patrons through the mail. So the machines undergo considerable stress in transit to patrons. In addition, our patrons use the machines heavily and we know the machines are sometimes dropped, liquids are spilled on them, and in general, they receive a fair amount of punishment. We wonder how well the precision elements of CD-ROM players will hold up under these conditions.

We repair about 1/5 of our inventory of machines each year -- about 120 000 cassette players. The work is done by a large network of volunteer groups. NLS calculates the value of their labor at about $4.5 million annually.

We are concerned that sophisticated devices such as CD-ROM players would be beyond the skills of our volunteers thus forcing us to pay commercial rates for the repairs -- something we could not afford. Indeed, they may only be repairable at the subassembly level, which would also be quite expensive. Our hope is that we can migrate directly from analog cassette to a solid state player that would require minimal maintenance.

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5. A Future Digital Talking Book System

If we could wish for a perfect system, it would have these characteristics:

  • Digital
  • Solid state storage -- no moving parts
  • No physical medium to transport, store, incur damage, etc.
  • Flexible system, so it can easily adapt to changing technology.

Does such a system exist? Well, a good prototype appeared just a month ago in the American marketplace. Called Audible Inc., this company is a commercial venture aimed at selling audio content via the world-wide web. The user selects items from Audible's web page and downloads them to their PC (about fifteen minutes). They then transfer two hours of AM-radio-quality content from the PC, through a docking station, to a portable playback unit (another fifteen minutes) where it is stored in solid state memory. When that portion of the book has been read, they load another two hours of material. The playback device is about the size of a deck of cards and contains a headphone jack. You can find their web site at audible.com.

Clearly, there are significant limitations with this system that would make it unusable by our readers. First, the transfer rate is too slow. Second, we would want better sound quality than AM in a digital system. Third, we would expect to have at least ten times as much material available on the player at any time. But these are all limitations of degree, rather than absolute barriers.

For such a system to be feasible for the NLS program, three things will have to occur:

  1. The cost of solid-state memory devices must decline by a factor of 10, approximately. Moore's Law, named after one of the founders of the Intel Corporation, states that the power of silicon chips doubles, and their costs are cut in half, every 18 months.

    Assuming that this "law" continues in effect, as it has for the last 20 years, it would take about 6-8 years for the cost of memory chips to fall within the range where they become feasible as a storage medium for our program.

  2. Transmission speed to the patron, whether via Internet, telephone lines, cable, etc. must increase significantly. A T1 line requires close to 40 minutes to transmit a compressed 12-hour audio book.

    ADSL (Asynchronous Digital Subscriber Line) is a promising option that is being pushed by American telecommunications companies anxious to add more bandwidth for Internet users. ADSL was originally developed to offer video on demand services over current twisted pair telephone lines. It can carry around 6 Megabits/second of data to the subscribers, and much less in the other direction. So a 12-hour book would take about 8 minutes to transmit. ADSL is well-designed for talking book applications, where you would see occasional messages of short duration sent from the reader to the library followed by the download of an enormous quantity of data in a short time. How widely this service will be available remains to be seen.

  3. The cost of telecommunications must decline. Currently books are distributed at no cost via Free Matter for the Blind. Moving to a system where the library incurs a charge each time a book is circulated would have a dramatic impact on the budget. One factor that might help offset such costs for NLS is found in a U.S. law passed just last year. The Telecommunications Act of 1996 offers the promise of large discounts ranging from 20-90% on telecommunications services for schools and libraries. These discounts were created to ensure that schools and libraries were not excluded from the benefits of the Information Superhighway because of economic limitations. Our hope is that our network libraries will qualify for the highest discount, making telecommunications-heavy solutions economically feasible. Of course, if we are able to use the Internet as a delivery channel, that could limit costs dramatically as well.

A system like the one described above would add to the benefits discussed earlier a more rapid delivery of information to our readers. Magazines, for instance, would be accessible several days to a week earlier than they would be if they were sent through the mails. In addition, the library would be spared the costs of duplicating and storing multiple copies, handling the books when shipped and returned, and inspecting them for damage. Instead, the library would house enormous digital archives and an array of servers -- all technology that is declining in cost.

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Moving from our current system to a digital one will be a challenging and exciting process. In a recent article, Robert Lucky, Vice President for Applied Research at Bellcore, formerly Bell Labs, highlighted the difficulties of planning during this time of rapid change. "Moore's law," he said, "...guarantees that technologies become obsolete and that economics become overturned at a rate that is incompatible with most infrastructure planning and financing."

A frightening statement for those of us with large inventories of equipment and collections. However, if we are flexible and able to cooperate and learn from each other, we can meet the challenge.

Certainly it will be an exciting process. As digital talking book systems are brought into being they will bring a great range of benefits to blind and physically handicapped readers. Many of the marvelous capabilities of the print book will be combined with the power of computers to create a tool of unprecedented flexibility and power for print-handicapped readers. We look forward to sharing this exciting transition with you.

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