Screen Reading Technology and Refreshable Braille Displays
Narrator: This segment features screen review software, which is often called screen reading software or simply a screen reader. We’ll also look at how screen readers interact with speech synthesizers and refreshable braille displays.
Screen review software translates on screen information into electronic text. This electronic text is then sent to a speech synthesizer or a refreshable braille display. The user is then able to hear the text spoken or read it tactually with the refreshable braille display.
The software’s functionality gives users the ability to navigate around their computer screens,
Sample of synthesized speech: “…WinZip, Window – Eyes, Netscape Communicator, JAWS 5.0, Window Explorer…”
and read information by paragraph, sentence, word, or character.
Sample of synthesized speech: “…space l-a-z-y, space, dog, period, space d…”
Almost all the text on the screen can be accessed with screen review software but, unfortunately, it cannot access graphical information. Screen review software enables users who are visually impaired or blind to work with a large number of applications. With appropriate training on the right equipment, users can accomplish such tasks as creating word processing documents, and creating and reviewing financial information in a spreadsheet program. They can also send and receive email and browse the Internet.
As you can hear in this demonstration, when the cursor moves to a new line of text, the software sends it to the synthesizer to be spoken.
Sample of synthesized speech: “…Untitled print document 1, [blank] below is correspondence that actually occurred between a London hotel staff and one of its guests.”
The software will also alert users to events on the screen not created by a keystroke. For example, if a dialog box appears, the screen review software conveys to the user the information it contains.
The device shown here is an example of a separate hardware synthesizer that connects to the computer using a standard USB or serial port connection. Instead of using the system’s sound card, these devices create and emit speech through their own speaker system. This not only frees up system resources on the PC, but it also allows the sound card to be used exclusively for other audio. By activating commands built into the screen review software, a user can change the pitch, speech rate and tone of both hardware and software synthesizers. Not surprisingly, hardware synthesizers are more expensive than their software counterparts.
In addition to sending information to a speech synthesizer, screen review software can also send its output to a refreshable braille display, which is an additional piece of hardware that can be connected to the computer. A refreshable braille display contains a series of plastic pins, each of which equates to a dot in a braille cell. These devices may have between 18 and 80 cells. Each pin in a cell is raised or lowered to form a braille character. Once users read all the characters on the display, they press a key and the display refreshes or presents the next group of characters. Many users of screen review software prefer to read information in refreshable braille. Using this technology can increase the efficiency with which the user accesses information and accomplishes tasks.
Screen review software can also provide a visual representation of the braille on the computer’s monitor to assist instructors or colleagues working with the braille reader.
Refreshable braille displays are relatively expensive, ranging from $5,500 to $11,000 but in many cases, improved efficiency justifies the additional cost.
Users who just want to access the computer through synthesized speech can choose a shareware program or the Narrator feature available in Windows 2000 & XP, but they all have strictly limited capabilities.
Commercial screen readers offer many more features and range in price from $595 to $1095, depending on features and upgrade options.