Computers have taken a dominant role in our society meaning most jobs now require access to computers and the internet. But what happens if a person is blind, deaf or motor-disabled? they needn't worry. the latest assistive technology is designed to help them use computers and do their jobs in the office, learn at school, or interact with their families at home. in addition, new laws oblige companies to adapt the workplace to accommodate disabled people for example , the americans with Disabilities Act (ADA) and the UK's Disability Discrimination Act make it illegal for employers to discriminate against people with disabilities to work effectively, most blind users need to have their computers adapted with technologies such as Braille, screen magnifiers, speech synthesis and optical character Recognition(OCR)
Braille keyboards have Braille lettering on keyboard overlays, allowing the blind user to easily identify each key. For output, there are printers , called Braille embossers, that produce tactile Braille symbols on both sides of page at high speed.
For someone with limited but usable vision, a screen magnifier may be appropriate . this type of software can enlarge text and images appearing on the screen by up to 16 times.
A speech synthesis system is used to read aloud the work on the computer. It has a speech synthesizer, which produces the audio output, and a screen reader – the program which reads aloud text and menus from word processors, databases and the web.
OCR uses a flatbed scanner and specialized OCR software to read printed material and send the text to computer. The pc can them produce a copy of the text in Braille, a magnified copy, or a version that can be read aloud by a speech synthesis system
Deaf computer users can overcome many
Communication difficulties with the aid of visual alerts electronic notetakers and textphones visual alerts are indicators that alert the user when they receive new mail or when there is a system error . so instead of hearing a sound the user is alerted by blinking menu bar or by a message on the screen. Electronic notetakers use software that types a summary of what is said in meetings onto the computer screen
Textphones allow the deaf to type and read phone conversations. They are also called TDDs (Telephone Devices for Deaf) or TTYs (TeleTypewriters) . They can be used in combination with relay services, where an operator says what the text user types, and types what a voice phone says Deaf can also communicate via SMS and instant messaging.
Motor-impaired workers unable to type on a standard keyboard can employ expanded or ergonomic
Keyboards on-screen keyboards , adaptive switches and voice recognition systems
on-screen keyboards are software images of a keyboard that appear on the screen and may be activated with a trackball, touch screen, screen-pointing device, or eye movements in an eyegaze system , the keys on the virtual keyboard are activated by the user’s eyes when they pause on a key for two or three seconds
Switches come it many shapes and sizes. They are operated by muscle movements or breath control. For example, a pneumatic switch – known as a sip and puff – allows someone with quadriplegia to control the pc by puffing and sipping air through a pneumatic tube. People with quadriplegia can also use sip and puff joysticks.
Finally there’s voice recognition, which allows the computer to interpret human speech, transforming the words into digitized text or instructions