HOMETechnology Overview
What is a DTB?
A traditional talking book is an analog representation of a print publication. A Digital Talking Book (DTB) is a multimedia representation of a print publication. In both instances the rendering of the audio is in human voice.
At a very early point in the development of the DAISY standard, talking book readers from many countries were consulted regarding their reading requirements and their vision of a fully accessible audio book. Those who provided input made it very clear that analog recordings did not meet their reading and information needs. Access to points within the books, awkwardness of the medium itself, sound quality plus numerous other issues indicated that producers of talking books had to begin the move to a digital platform. However, a digitally produced human voice talking book in itself would not resolve all of the issues, particularly the issues of accessibility and navigation from point to point within the book. DAISY DTBs do meet talking book reader requirements by providing access to the talking book that has never before been possible with a human voice production of a print book.
There are three types of DAISY DTBs as outlined in the DAISY Structure Guidelines. All offer improved access to the content.
The three basic types of DAISY publications are:
- Audio with NCX: DTB with structure. The NCX is the Navigation Control Center, a file containing all points in the book to which the user may navigate. The XML textual content file, if present, contains the structure of the book and may contain links to features such as narrated footnotes, etc. Some DTBs of this type may also contain additional textual components, for example, index or glossary, supporting keyword searching.
- Audio and full text: DTB with structure and complete text and audio. This form of a DTB is the most complete and provides the richest, multimedia reading experience and the greatest level of access. The XML textual content file contains the structure and the full text of the book. The audio and the text are synchronized.
- Text and no audio: DTB without audio. The XML textual content file contains the structure and full text of the book. There are no audio files. This type of DAISY DTB may, for example, be rendered with synthetic speech or with a refreshable braille display.
XML provides the producer with the ability to structure a book in great detail. Compared to HTML markup, XML increases markup options and makes more detailed structure and proper nesting possible.
DTBs produced to the DAISY standard are in and of themselves independent of distribution medium, that is, the digital master file can be archived and may also be distributed on currently available media such as CDs or DVDs. More importantly, as technology advances and digital media distribution methods evolve, these same books can be distributed via the newly developed media or system.
