Individuals who can read braille may prefer it to audio as a means of accessing information from a computer. This is particularly true for programmers and others who need to closely proofread their work. Refreshable (electronic) braille displays allow blind individuals to access on-screen text.
Refreshable braille devices have multiple braille 'cells', spaces on a surface that correspond to the 2-column-3-row layout of braille dots. Each cell has 6 pins that can be raised or lowered electronically, creating the dot pattern for the character. For example, the letter 'a' is created by raising only the top left pin.
If the device has 40 pins, it can display 40 characters at a time. Users can move through a document, and the display will raise and lower the pins to produce the next 40 characters. Some devices vibrate the cell to show where the cursor is. A video from Accessites.org shows how refreshable braille works.
Some devices are standalone notetakers or readers, while others are connected to computers. Refreshable braille devices cost $1500 or more, so it's important to know about the needs and preferences of any users.