The National Library Service for the Blind and Physically Handicapped (NLS), Library of Congress, has recently completed two reviews: one for engineering design and the other for critical design. Both are essential steps toward finalizing the digital talking-book system’s technical specifications. During these important development phases, NLS examined technical specifications for the digital player, book, and mailing containers to ensure they operate properly and meet all required specifications. The system passed inspection and NLS has advanced to the manufacturing stage.

The engineering design review, conducted in early April, followed patron testing of functional prototypes and subsequent refinements to the digital player. Michael Katzmann, chief of the Materials Development Division, led the review and was joined by a team that included NLS engineer Peter Woo, contractor Don Pieper, and representatives from both Battelle and HumanWare.

During the engineering design review, all technical and mechanical specifications of the player, cartridge, and containers were examined to ensure that each function performed optimally. The team checked and finalized a range of elements, including the player’s battery and electromagnetic compatibility. NLS tested the battery to confirm that the device would retain power even if electricity falls below normal levels. NLS was also interested in how long the battery stored power and whether the battery would recharge itself properly under low power. Engineers were pleased with the battery’s performance and approved its specifications.

The Federal Communication Commission’s standards for electromagnetic compatibility are among the many specifications the digital player must meet. Specifically, the machine’s emissions and functionality cannot be disrupted by outside electrical interference, such as AM or FM radio emissions. The player’s electrostatic discharge is another important issue. The machine must resist sparks and outside static charges and be able to reset itself should it encounter static. NLS engaged an independent lab to test the player’s electromagnetic compatibility. The tests revealed that the machine does meet FCC standards.

With the engineering design issues settled, NLS moved on to the next stage of the preproduction process, critical design review. Conducted in late April, the review provided an opportunity for all parties involved in design and development of the digital system to conduct a full audit of every aspect of the machine and cartridge design.

"The critical design review is essentially a top-to-bottom review of the design so far to ensure it meets NLS expectations and standards. It really helps us hone the design and resolve any software and mechanical problems that could potentially disrupt manufacturing," noted Katzmann.

The critical design review confirmed that all designs are operational and ready for production. NLS can now provide manufacturers with a technical data package that will guide them in building the player.


NLS will soon open a bidding process to identify a contractor to manufacture digital players. Once a contractor is identified, Battelle will transfer all design plans as well as provide 250 preproduction prototypes for distribution to selected individuals and agencies for additional testing. Following this testing, the manufacturer will produce 5,000 machines for field testing.

"We’re pleased to have completed the engineering and critical design reviews," said Frank Kurt Cylke, NLS director. "These assessments confirm that our designs for the key components of the digital system are functional and can be built with confidence. With these milestones behind us, we will move forward to produce and test preproduction prototypes."

Members of the NLS Materials Development Division inspect the digital talking-book player.

Members of the NLS Materials Development Division inspect the digital talking-book player. From left: Alice Baker, assistant to the chief; Michael Katzmann, chief; and electronics engineers Lloyd Rasmussen, Raouf Amin, and Peter Woo.

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Digital Talking Book (DTB) Milestones


Start 1/12/04
Finish 10/1/08
Milestone Start Date
Distribution system implementation 10/2/2006
Flash-cartridge contracting/production 3/2007
Flash cartridge duplication 5/2007
Manufacture initial lot of DB containers and labels 8/2007
Full player production 12/2007


For Information on the NLS Digital Project contact:

Jean M. Moss, Digital Projects Coordinator
[email protected]  Fax: (202) 707-1690

To view the strategic business plan on the Web visit