Similarly, those who could not hold books or turn pages found themselves excluded from the world of print information. The invention of braille and other tactile reading systems partially helped those who were blind, but its expense and bulk limited its usefulness. In the twentieth century, radio and recordings have helped narrow the gulf, but it has been the computer that has created a new world of access to information. When information is digitized and stored in a computer, it can be manipulated in many ways. Visually impaired readers can use software that enlarges the display on the monitor to permit their reading it.
Speech synthesizers can speak the material on the screen for the reader who is blind.
Alternate input devices permit persons with motor impairments to operate a computer and to move through the text without having to hold a book or turn pages. Voice recognition systems can operate a computer. Other devices are available for a variety of motor disabilities. Digitized information is also changing dissemination systems. Stores, libraries and postal delivery continue to play an important role in getting information to the user, but the so- called information highway, the complex global network of phone lines, cables and satellite transmitters have become a major mechanism to bring the user and the electronic text together.