A Different Kind of IT

Allikas: KakuWiki
Mine navigeerimisribaleMine otsikasti

What if...?

For a common computer user, his/her way of working is so self-explanatory that it is often forgotten how much it actually takes. What if

  • ...we couldn't see, so the display is useless?
  • ...we had only one hand – or none?
  • ...our fingers couldn't flex?
  • ...we had so poor control of movement that even hitting the keyboard unit was difficult, more so for a specific key?
  • ...we lacked the muscle power to press keys?

In fact, many people who have these problems do use computers daily. Today, we'll talk about how.

People with more profound disabilities often face a choice when trying to use computers - whether to opt for special assistive solutions or to make do with mainstream solutions, possibly just adapting them somewhat. A specially designed piece of assistive technology can be more fitting and comfortable, yet it can be expensive and also makes the user dependent on it. It can also be difficult to use more specific adaptations on computers used by many people (e.g. a large family or a workgroup). Ideally, assistive technology would be unnecessary - all solutions should be accessible (as dictated by universal design). In reality however, vendors of IT solutions can overlook accessibility, making assistive solutions necessary. Still it pays to inform device manufacturers of more interesting use cases as they may consider them at their future designs.

Assistive IT tends to concentrate on two major groups of disabilities - visual impairment and various disabilities affecting mobility and motor control. For comparison, hearing impairment does generally have less impact on computer usage - although audible information plays a part in computing, it is considered secondary compared to visuals. As for developmental and behavioural disabilities, they can be addressed by mostly methodological (special education etc) measures - although assistive solutions do exist there as well.

Visual impairment

Assistive solutions for this group of disabilities tend to be more sophisticated and expensive than for others, falling into three main categories - screen magnification (used for people with decreased vision), sound (screen reading) and tactile output (mostly Braille).

Some points:

  • many applications (especially screen readers) are language specific and small languages can be in a disadvantage (for some time, Estonians had to use Finnish and German software that distorted Estonian language pretty badly).
  • dependency on operating system and hardware - regrettably, quite a lot of assistive technology is "Windows only"; also, changes in hardware (e.g. new video card) can disturb assistive solutions.
  • other software must follow standards - while it should be a norm, it is not. Many clever hacks that otherwise work well will be bad for accessibility.

The following is a quick overview of common assistive solutions for visual impairment.

Screen reader

A screen reader can be implemented in both hardware and software; its purpose is to recognize text sent to display and send it to either a speech synthesizer, Braille monitor or embosser (printer). Examples include

  • JAWS - the most used proprietary reader on Windows
  • Emacspeak - free and open-source, cross-platform
  • Speakup - free and open-source, mostly Linux
  • Microsoft Narrator - a simple reader bundled with MS Windows XP and newer
  • VoiceOver - a full-scale reader coming with OS X

Proprietary solutions have traditionally been expensive, relying on large subsidies (actual users have to pay only a fraction of the price). E.g. in 2015 in Estonia, JAWS users had to pay 110€ - although there is a gratis test version available (works for 40 minutes, after this the computer must be rebooted to continue), the old DOS version is also free of charge. There is no Estonian support yet, but Finnish is supported and the experimental Estonian speech synth can also be used with JAWS.

For some time, free and open-source solutions lagged behind in this field, compared to proprietary ones. A reason can be that many FLOSS projects grow out from actual needs of the initiator - and while developers with disabilities do exist, they are scarce. Still, as e.g. Linux distros have matured, they have paid more attention also to accessibility. Most Linux distros include Orca - an integrated assistive solution.

Speech synthesizer

A speech synth will provide audible output from text typically read by a screen reader (the two are increasingly integrated, both in software and hardware versions). Besides people with visual impairments, it also helps people who have impaired speech (typically due to trauma or spasticity, e.g. from cerebral palsy). The Estonian screen reader also includes the speech synth. From free and open-source software, ESpeak has become increasingly usable recently, also supporting Estonian.

Screen magnification

For impaired (but not missing) vision, screen magnification can help. In principle, these applications provide a 'virtual magnifying glass', a window that displays everything below it magnified with the factor of 2-16. Some magnifiers can work together with screen readers.

There is a number of proprietary applications (e.g MAGic Pro), but some of them are free of charge. From FLOSS, Orca has a simple magnifier, other similar projects include GMag for GNOME and KMagnifier for KDE.

Points to consider:

  • using large magnification usually makes the text ugly and jagged.
  • sometimes the magnifier can be hard to control, especially if an application tries to automatically focus on a window.
  • also here, graphic drivers and non-standard solutions can cause problems.

Braille display

A device for dynamic presentation of Braille, using Braille elements with protruding knobs; the line can have 18-80 cells (characters). Historically, they have been among the most expensive assistive solutions - while prices have somewhat dropped recently, it is still more costly than voice output (in Estonia, the payment can exceed 1000€). On the other hand, using Braille is also more flexible (e.g. for programming). Braille is also the primary assistive technology for people with both visual and hearing impairment (deaf-blind people).

Braille embosser

Also known as Braille printer, these devices output Braille on paper (or a special plastic). New models can reach speeds of about 2000 characters per minute, but they typically need special paper (it needs to be stronger to withstand repeated reading by touch) and due to physical embossing, the process can be noisy.

Braille keyboard

The Braille keyboard has descended from the Perkins Brailler, a special typewriter for producing Braille. Both devices have 6 or 8 main keys corresponding to the dot positions in a Braille cell, they are pressed in 'chords' or combinations, producing a single Braille character. With less keys a Braille keyboard is more compact than a generic one, yet many blind users stick with the latter due to greater freedom in using different computers. A generic keyboard can also be added a set of tactile (Braille or other) caps or audible feedback.

Tactile mouse

A descendant of generic computer mouse with tactile cells on top. Some prototypes can be seen here: http://www.nise.go.jp/research/kogaku/twatanab/Tactile/TactileMouse/TactileMouseEn.html .

PDA-s (handheld computers)

A version of generic PDA-s (that by now have been largely overshadowed by tablets and smartphones). The devices typically have a hardware speech synth and/or Braille display for output and either a generic or Braille keyboard for input. See examples at https://store.humanware.com/blindness/braillenote-touch-notetaker/ .

Braille E-book readers

Still under development (e.g. see https://www.bbc.com/news/technology-27243376 and https://blitab.com/), these devices will make use of electroactive polymers that change physical shape when electricity is passed through them.

Physical and mobility impairments

This is a very diverse field of challenges - muscular dystrophy, limited reach, various motor control problems (e.g. many forms of cerebral palsy), missing or paralyzed limbs, arthritis etc. IT-related problems include difficulties in changing media (e.g. USB sticks), using key combinations, etc. Assistive solutions here are mostly hardware, but software plays a vital part in e.g. switch access (onscreen keyboard).

The main principle is - if a person has control over any function, it can also be used to control the computer. Sometimes, all it takes is creative placement of ordinary devices (e.g. placing the keyboard at one's foot). Sometimes, alternative devices (e.g. ergonomic keyboards, or using trackball instead of mouse) suffice. Special devices may be brought in to enhance the functionality of a mainstream device (e.g. adding a keyguard to a generic keyboard). But for difficult cases, there is also a choice of specialized devices available.

Use the imagination

A keyboard can be placed on the floor and used with feet when the person has better control over them (e.g. some cases of CP). The cable may have to be replaced with a longer one, and the whole layout of such a workplace must be well-designed. If feet cannot be used, one can use other body parts - the more common solutions include mouth- and headsticks used to press keys on keyboards (in this case, the keyboard is either on the table or attached vertically to a wall or other suitable place near the user's head). Sometimes, keyboards or pointing devices can be placed suitably using a special mount (e.g. http://www.inclusive.co.uk/hardware/mounting-options). But there are also more specialized solutions like the Tracker Pro (http://www.inclusive.co.uk/trackerpro-p2436).

For pointing devices, using a joystick or trackball instead of a mouse is often a better solution. For instance, they (especially dedicated assistive models) can be used to control the computer without using fingers, or when placed differently, can be operated in a wide variety of ways (e.g. a trackball mounted under the chin).

There are also two generic devices that can have an assistive role. First, an ordinary OCR-capable scanner can be used to input longer texts that otherwise may take long time to enter (unfortunately, this is again language specific - Estonian OCR is not foolproof yet). The other device is webcam - used with fast enough connection, it allows deaf people to use computer as a sign language communication terminal.

Adapted devices

Sometimes, small adaptations are enough. For example, a set of simple software utilities that appeared as an extra package for MS-DOS (AccessDOS), gradually found its way into all modern operating systems. The utilities are named somewhat differently in different places, here the original AccessDOS terms are used:

  • StickyKeys allows to replace key combinations with a sequence of keys; all special keys (Ctrl, Alt, Win etc) will wait for a subsequent key to be pressed to form a key combination. This is vital for users of single input device, e.g. a mouthstick or a single finger.
  • RepeatKeys delays the key repeat mechanism (usually applied after about 1.5-2 seconds of holding the key). People with poor motor control often struggle with unwanted symbols - RepeatKeys allows adding to the delay or turning the repeating off altogether.
  • 'SlowKeys adds a delay to input, mandating holding a key down for e.g. 2 seconds before the character is sent. While this slows down typing speed, it also helps people with motor control problems to avoid hitting wrong keys by mistake.
  • MouseKeys allows controlling the mouse with the arrow keys on the keyboard.

A keyguard is a plastic or metal overlay with holes that is attached above the keyboard. In order to hit a key, the user must insert the finger or input stick to a hole - it becomes impossible to accidentally veer to another key.

Assistive designs

For both keyboard and pointing device, there are several assistive variants, including

  • membrane keyboard - similar to small, solar-powered pocket calculators, these keyboards are flat and smooth, with keys below the elastic surface that take minimal effort to be pressed.
  • enlarged keyboard can be used with poor motor control, or also to be operated with feet.
  • minikeyboards help people with limited reach and/or muscular power.
  • chorded keyboards are operated with key combinations similarly to the Braille keyboard described above. There are e.g. models that are meant for single-hand use.
  • concept keyboards use each key to convey not just a character, but the whole concept (meaning). These keyboards are often programmable with changeable overlays (e.g. https://overlaykeyboard.com) and used in special education.

For pointing devices, options include

  • a wide variety of special mice, joysticks and trackballs - a common quality is that the balance of the devices is different, with typically a massive base aand a smaller handle or ball. Especially sturdy are the foot-operated versions.
  • touchscreen monitors (especially large ones) can be easier to operate than pointing devices. They can also be an option for some developmental disabilities when the connection between the on-screen cursor and the pointing devica is not understood by the person - pointing to the screen is considered to be more natural.

Switch access

Most common people probably think about the button used to turn lights on and off, yet switches are also used to control computers when other kinds of access are ruled out.

Even keyboard and mouse can be considered as sets of switches - each key is a switch, so are mouse buttons. Switches used to control computers are very diverse, from simple buttons to special stickers registering even a slight movement of e.g. cheek muscles. As said before, any function can be used. Switch access however relies on special software, mostly onscreen keyboards and pointers.

Basically, both a keyboard and a mouse can be emulated with a single switch (it is impractical though, a larger number makes the work much more confortable) - at first a menu alternating between keyboard and mouse is displayed. Say the user wants to type 'F' on keyboard - he or she will choose keyboard by activating the switch, after which the menu alternates between keyboard rows (F-s, numbers, Tab, Caps, Shift, Ctrl). After choosing the Caps row and waiting for the cursor to reach F, the letter is chosen by the same switch. Likewise, a mouse can be used with different choices for Left or Right click, double click, drag and drop etc.

A special kind of switch is the sip-and-puff switch used to control the computer by breathing in and out through a tube. It can be used to give simple signals, but the most common usage is for entering Morse alphabet - both for commands and text editing.


Assistive IT has come a long way during the last decades - many solutions allow even people with profound disabilities to work on par with others. Technologically, it is a combination of hardware, software, networking - and most of all, MacGyver-style 'out of the box' thinking.