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DAISY: a new approach to braille and Talking Books

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Markus Gylling

Swedish Library of Talking Books and braille, DAISY Consortium, Suède


In the Information Age, access to information is a fundamental human right.
from George Kerscher's presentation to the United Nations, Bangkok, June 2002


This paper is an introduction to the activities of the DAISY Consortium. DAISY - the Digital Accessible Information SYstem - is an accessible, feature-rich, navigable, open format for Digital Talking Books (DTB), extending into multimodal representations in braille and large print.

The position of the Consortium within the standardization space is discussed, with focus on the state of progress in achieving a worldwide, open standard for accessible information.

The central principles of multiple modalities, multiple media types and intelligent navigation are described using the DAISY Digital Talking Book and the DAISY reading platform AMIS (Adaptive Multimedia Information System).

A global consortium with a common mission


The origins of the DAISY standard are to be found in Sweden, where during 1994 a research project was started with the aim of finding methods for using a digital format for talking books.

The project was successful, and lead to international interest. The DAISY Consortium was formed in 1996 by a group of talking-book libraries to lead the worldwide transition from analog to Digital Talking Books. Initially, member organizations came from Japan, Spain, Great Britain, Switzerland, Holland and Sweden. Since then, the Consortium has been constituted as a not-for-profit association under Swiss Law.

Today, the consortium consists of 12 Full Members, more than 40 Associate Members, and more than 10 Friends [1]. Every populated continent of the world is represented in the DAISY Consortium.

Five major goals

The DAISY Consortium has identified five major goals that defines the common mission and guides the work undertaken. These goals are:

2003: Implementation status

Although no exact numbers exist, it is estimated that approximately 40000 DAISY Digital Talking Books have been produced worldwide[2]. The DAISY Consortium currently offers, as a benefit of membership, access to three different production tools, and production tools are commercially available as well. Several reading systems exist in hardware and software form, commercially as well as freely available[3].

An evolving standard

Over the last five years, the DAISY standard has evolved considerably from a technical and feature-set perspective. The DAISY 2.0 specification, published in 1998, was based on the W3C specifications HTML and SMIL 1.0. The Daisy 2.02 specification, was published in 2001 and represented the first move to a purely W3C XML based standard. These specifications were authored and maintained by the DAISY Consortium.

ANSI/NISO - towards ISO

In 2001, The American National Standards Institute (ANSI) and the National Information Standards Organization (NISO) endorsed DAISY 3 as a standard (ANSI/NISO Z39.86-2002)[4]. ANSI and NISO are formal standards bodies, recognized in the USA.

The DAISY Consortium has also endorsed this specification for all new developments, and is planning to move this standard towards the International Standards Organization (ISO).

The DAISY Consortium and the National Library Service for the Blind and Physically Handicapped (NLS) share maintenance responsibilities for ANSI/NISO Z39.86-2002. An Advisory Committee is in place to identify any errata, review additions and modifications, incorporate new specifications, and to promote the standard. Denmark, the United Kingdom, Sweden, Japan and the USA are currently represented on this committee.

USA: Instructional Materials Accessibility Act and the National File Format (NFF)

In the USA, the first legislation that requires publishers to provide files to the production of braille and other accessible formats was passed in 1991. Since that time, the legislation has suffered from not having a common file format standard to reference.

Most recent pending legislation (The Instructional Materials Accessibility Act (IMAA)), calls for the establishment of an agreed upon national file format. Independently, the Office of Special Education has funded the identification of a national file format for accessibility.

On March 11, 2003, the DAISY 3 (ANSI/NISO Z39.86-2002) XML DTD (Dtbook) was selected as the format to use for the National File Format.

Convergence and mainstream adoption

The DAISY Consortium works closely with other standards organizations such as the W3C and the Open eBook Forum (OeBF) to insure that DAISY standards build on existing specifications. As mentioned above, the strategical position of the DAISY Consortium is to move towards converging standards wherever possible, and to move the DAISY standard into the mainstream of audio and electronic publishing.

World Wide Web Consortium (W3C)

There is a close alignment between the DAISY Consortium and the W3C. DAISY is committed to promoting and using W3C recommendations to the widest extent possible. DAISY members participate in W3C working groups in the development of standards (such as WAI, SMIL 1, SMIL 2, MathML and Timed Text).

Efforts such as WAI, MathML, SMIL and Timed Text are all relevant for us to keep current about - because they are building blocks for the DAISY models of structured mark-up and navigation. DAISY receives from the Web community, and also gives.

The Open eBook Forum (OeBF)

The OeBF is an international trade and standards organization for the electronic publishing industry. Members consist of hardware and software companies, publishers, accessibility advocates, authors, users of electronic books, and related organizations whose common goals are to establish specifications and standards and to advance the competitiveness of the electronic publishing industry.

The DAISY Consortium has worked in close collaboration with the OeBF to ensure interoperability between the two standards. In the upcoming version of the OeBF format, the DAISY navigation model is scheduled to be adopted.

So far, the OeBF format has not been multimedia oriented (focusing on electronic text only). There is an expectation that eBook publishers will start migrating towards multimedia in their eBooks - the lack of this feature in existing eBook technology has to a certain extent disappointed both end users and publishers. The DAISY standard becomes central here, being one of the most well-established and advanced book oriented multimedia specifications available at this point in time.

Audio Publishers Association (APA) and Consumer Electronics Association (CEA)

Large parts of the audio publishing industry focus on commuters who are driving in their cars. It is assumed that these commuters will want the same high quality digital audio they have with MP3 music, now, and that they will want a familiar playback device that provides at least minimal navigation.

Looking for the broadest playback environment possible, the APA has created a specification that provides a linear-oriented reading experience of audio material. The DAISY Consortium participated in the development of this specification, endorsed by the Consumer Electronics Association in 2002. This specification is compatible with DAISY; it is explicit that both formats can coexist on the same media. Thus, the playback device can choose which format to use for playback. Whereas the CEA/APA specification would provide a limited audio reading experience in an automobile mp3 player, the same publication would yield the richer DAISY feature set when presented to a DAISY-aware reading device.

Commercial DAISY books

In 2003, the DAISY Consortium's Friend, Dolphin Computer Access, and its Associate Member, the American Foundation for the Blind, worked on a groundbreaking project with Time Warner AudioBooks to produce the World's first mainstream "Audio E-book" in the DAISY format - "The Jester" by James Patterson and Andrew Gross[5].

This is not the only commercial publisher that is looking into the DAISY format. Random House Audio is investigating the same approach. European audio publishers (such as BBC) have shown interest as well.

Similarly, the Government printing office (GPO) that publishes all government documents in the USA, has produced their first DAISY book to test public acceptance. This book was distributed as an alternative format to the print based publication. Since the evaluation of this test publication, there is ongoing discussion about GPO becoming a member of the DAISY Consortium.

Multiple media, multiple modalities, intelligent navigation

The DAISY format has been created using Universal Design Principles, targeting the needs of diverse user groups. Since a "print disability" spans from blindness, vision impairment and dyslexia through motor and cognitive disabilities, this means that the accomplishment of high usability and accessibility can only be done via extensive adaptability in terms of the flexibility of the components of the format.

Basic components of the DAISY format

Dtbook - a conversion XML DTD[6]

The Dtbook XML DTD defines an XML vocabulary (element set) for representing the structural and semantical aspects of the information. Dtbook is created to represent textbooks; in this respect elements are provided that represent block-level structures, as well as inline elements for more granular item identification (sentence, word, etcetera). While partly using the XHTML vocabulary, Dtbook extends and refines this by introducing a hierarchic block-level structure, and essential textbook elements such as sidebars, notices, footnotes, and annotations.

Going further from the core set of approximately 80 structural and semantical elements, Dtbook includes a mechanism for adding subject-specific modules, such as poetry, drama, mathematics and science. This means that the DAISY format is extensible in terms of the nature of the information which can be offered to users.

The Dtbook element set has considerable application outside of the digital talking book as well. It was designed to enable the production of documents in a variety of accessible formats. At least one braille translation software package has implemented a facility that imports Dtbook documents and automatically translates and formats them in Grade 2 braille. It is expected that similar automated processes will be developed for converting properly marked-up documents into large print and for rendering Dtbook documents in braille, synthetic speech, and large print "on the fly." Finally, an attribute called "showin" is incorporated in the Dtbook element set to control the display of selected segments of a Dtbook document. For example, descriptions of a graph might vary between braille and large print editions; "showin" could allow only the appropriate version to show in each edition, although both would be present in the Dtbook document.

SMIL - synchronization of multiple media types

The W3C Synchronized Multimedia Integration Language (SMIL) is the "spine" of a DTB. Using this specification, different media types (text, audio, images) are synchronized temporally. Further, SMIL allows for conditional rendering, meaning that the user can "skip" or "escape" parts of the presentation at will.

The DAISY specification identifies six types of books that have varying amounts of text synchronized with audio and other media types. So far, the full audio DAISY Digital Talking Book has been the most common. However, one class of book contains only text with no speech - in this case, the information would be conveyed through synthetic speech, refreshable braille or dynamically generated large print.

NCX - the Navigation Model

The Navigation Control file for XML applications (NCX) exposes the hierarchical structure of a DTB to allow the user to navigate through it. The NCX is similar to a table of contents in that it enables the reader to jump directly to any of the major structural elements of the document, i.e. part, chapter, or section, but it will often contain more elements of the document than the publisher chooses to include in the original print table of contents. It can be visualized as a collapsible tree familiar to PC users. Its development was motivated by the need to provide quick access to the main structural elements of the document without the need to parse the entire marked-up text file, which in many cases may not be present at all. Other elements such as pages, footnotes, figures, tables, etc. can be included in separate, nonhierarchical lists and can be accessed by the user as well.

It is important to emphasize that these navigation features are intended as a convenience for users who want them, and not a burden to those who do not. The alternative of a simple linear playback of the book will be available for those users not requiring the navigation features of the NCX.

AMIS - AMIS Adaptive Multimedia Information System

AMIS, the Adaptive Multimedia Information System, is a project initiated by the Japanese Society for Rehabilitation of Persons with Disabilities. The goal of AMIS is to develop an open source software product that provides a flexible user interface for reading DAISY content. The user interface of AMIS is easily customized using "skins" and extended through the plug-in architecture. Through plug-ins, AMIS is able to support alternative input/output devices, such as large print and refreshable braille output; and gamepad and voice input. The flexibility and ease of plug-in support allows AMIS to be quickly adapted to the needs of a broad range of consumer groups with disabilities.[7].

AMIS builds upon open standards from W3C and the DAISY Consortium. Among the technologies used in AMIS are XML, CSS, SMIL, and DOM. The AMIS concept is platform independent and open. The first implementation of AMIS for the Microsoft Windows platform has been developed using Visual Basic and a second implementation using Java is underway for true platform independence.

AMIS is being made available at no cost to individuals and organizations worldwide. The goals of the AMIS Project focus not only on the availability of a Daisy playback system for the international community, but also look to AMIS as a vehicle for technology and knowledge transfer in developing countries. By making the source code freely available, programmers and technicians can learn about the open standards behind the AMIS software (such as Daisy, XML, and SMIL), the underlying software architecture, and can make use of such knowledge to adapt the software to local requirements or create enhancements and extensions to the core software. As the AMIS Project continues, training courses for software developers are being planned in a number of developing countries.

Notes and references

[1]. Full list of current DAISY Consortium members.

[2]. Daisy Tools

[3]. Sweden has 13000 DTB in circulation; Japan approximately 20000; UK 4-5000, and USA 8000. Given several other implementations throughout the world, the count of 40000 is probably modest.

[4]. Links to the DAISY 3, ANSI/NISO Z39.86 standard:

[5]. Link to the Time Warner press release.

[6]. Theory behind the Dtbook DTD

[7]. Link to the AMIS plugin library.

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