Most talking books are still recorded on cassettes, which presently provide the most accessible reading medium for people with print impairment. However, it is difficult given today's implementation to look up information in a talking book or even to simply turn pages. Books used in school or on the job require contents pages, indices and other structure for fast and efficient reading. The need to digitize audio collections around the world is clear. Currently, each country has its own system and format for serving its clients.
Some countries use the common two-track cassette.
The lack of standards severely limits inter-library cooperation. All of the libraries produce books for their blind and print disabled clients and all have seen the end of the analog cassette quickly approaching. With the rise of the compact disc and now the mini disc, the traditional analog cassette is gradually falling into disuse. This is leading to a shortage of inexpensive audio cassettes and the equipment used to produce and duplicate cassette recordings. The digitization of books intended for persons with disabilities provides opportunities to increase the quality and availability of information to print disabled persons.