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Web Posted on: December 8, 1998


Digital Recordings Synchronized with Structured Text, How?

George Kerscher
Research Fellow
Project Manager to the DAISY Consortium
1203 Pineview Dr.
Missoula, MT 59802
Email: kerscher@montana.com
Phone: 406/549-4687

ABSTRACT

The heart and soul of the DAISY system is the synchronization of digital human recordings with structured navigation points. You might have full text or more commonly you might have the major navigation points and page numbers, but whichever type you are producing, you need to make the digital recording. In this presentation you will see in details the workings of the recording and mastering system that the DAISY Consortium has helped to make a reality. This presentation is intended for producers of Digital Talking Books (DTB) and for those blind and print disabled users who want to know what goes into the making of the next generation of information technology for persons with print disabilities.


Introduction

A Digital Talking Book has essentially three components. The first item you need is the structured navigation points marked up as text. The markup is in XML or it could be in HTML. This provides the major navigation points within the book. Chapter headings, sections, and minor headings along with the beginning of pages are all places in the book that the reader wants to get to quickly and efficiently. While full text is not an absolute requirement of a DTB, having the capability to search the text, spell words, to read the refreshable braille representation, or to look at the words being read to you is a tremendous benefit.

Of course, you must have the digital recording of human readers matter of typing in the headings and page numbers. Both methods produce valid DAISY DTB.

DEMONSTRATION: We will quickly look at the XML files and discuss how these were created. We will show the import process.


Step 3 Setting Digital Recording Levels

Digital recording is much different than producing analog recordings. You are using a computer and a sound card to create the recording and not magnetic tape. The controls are similar, but there are important differences. For example, the meters in analog recordings warn against too high input levels, but the analog recordings are very forgiving if the levels are set too high. The levels on a digital recording are much more critical. For this reason the meters in the DAISY recording studio are set up to make it perfectly clear what is going to create a professional quality sound.

DEMONSTRATION: The setup of the meters, positioning of microphones and testing input levels will be demonstrated. We will not have a sound proof booth, but you will be able to understand the process. This will be discussed in detail.


Step 4 Recording

The recording takes place by reading from a teleprompter for full text and from a print book for the more common navigation only type books. The teleprompter mode provides interesting user interface design issues. The automatic placement of SMIL synchronization marks is an essential component of this portion of the presentation.

DEMONSTRATION: Actual recording of passages will be demonstrated. We will perform retakes on certain passages. When a mistake is made the reader will go back and retake from where the mistake was made.


Step 5 Editing

After a recording is made, editorial corrections to the recording can be made. This involves inserts, deletes and cut and paste. This is a process that involves the simultaneous movement of three files. The text file, the synchronization file, and the audio file. All files must be kept in a state of synchronization. This is a complicated process for the software, but it is a simple process for the person using the sophisticated software.

DEMONSTRATION: The technician performing the work will show the movement of parts of the recorded book to fix errors and to add new material.


Step 6 Quality Control

Before a book is completed, it must pass quality control. The links must be tested to ensure accuracy. It is also necessary to confirm that all the parts are present in the final version.

DEMONSTRATION: Headings, page numbers and all links in the navigation center will be tested. Any errors will be corrected. This is a process of looking at the textual information and comparing it with the recordings associated with the text.


Step 7 Archive the DTB

Once a book has passed quality control the book is archived for future use. The sound files stored are very large. This is the richest sound quality possible. It is not unusual for a book to require more than 10 gigabytes of storage.

DEMONSTRATION: The book will be written to DVD. (simulation)

Step 8 Creating a CD-ROM for distribution

Once the book has been archived, the sound files are encoded to reduce their size. This allows us to put many more hours of digital recordings on one CD-ROM. We will discuss the types of encoders available on the recording work station.

DEMONSTRATION: We will encode in MPEG the recordings created during the demonstration. We will then simulate the writing of the CD-ROM.


CONCLUSION

You will have seen before your eyes the creation of a Digital Talking Book in the DAISY system. It is not simple, but the software and the processes established are designed for an efficient manufacturing environment. The training and technical support needed to move to the DAISY system is here today and this demonstration shows in one hour what takes place in great detail in the DAISY training courses.