- title Accessibility Guide
Ubuntu aims at making the operating system, and its derivatives, usable by as many people as possible across ages, languages and physical abilities. This includes providing an accessible platform with high quality assistive tools, and ensuring that other applications work well with these. The assistive tools on Ubuntu, along with the entire operating system, are provided free of charge.
- 1 Visual Impairments
- 2 Mobility Impairments
- 3 Activating preinstalled tools
- 4 Using Onboard and Mousetweaks at GDM
- 5 Resources
Built into Gnome desktop is Orca, a screen reading and magnification software suitable for blind and low vision.
Screen Reader and Magnification
Orca is a free, open source, flexible, extensible, and powerful assistive technology for people with visual impairments. Using various combinations of speech synthesis, Braille, and magnification, Orca helps provide access to applications and toolkits that support the AT-SPI (e.g., the GNOME desktop). The development of Orca has been led by the Accessibility Program Office of Sun Microsystems, Inc. with contributions from many community members.
Starting Orca on an Ubuntu installation
If you have Ubuntu installed, you can run Orca by pressing Alt + F2, typing
orca and then pressing Enter.
Starting Orca on the Live CD
- Once you've downloaded and burned the live CD image, insert it into your CD/DVD drive and reboot your computer. You should find that your drive spins for a short while and then stops. The point at which it stops coincides with the appearance of the language selection screen. At this point, you have about 30 seconds to perform the next step. If you do not perform the next step quickly, Ubuntu will automatically continue booting.
- Press enter to select English.
- In order to enable accessibility options, press F5. This will cause a list of accessibility options to appear:
- None (has focus)
- High Contrast
- Screen Reader
- Keyboard Modifiers
- On Screen Keyboard
- If you want to try Orca, you should press 3 to give focus to Screen Reader, followed by Enter to indicate your selection. You will be returned to the boot options screen then press Enter again to indicate you would like to boot.
- Within a few minutes, Ubuntu will be loaded with Orca running and you will hear a greeting such as "Welcome to Orca. Orca Preferences. Tab list. General page."
- The CD drive should also stop spinning at this point. If the CD drive stopped spinning and you did not hear a greeting from Orca, you might need to try to reboot from the CD and repeat the steps for selecting the Screen Reader.
- Now, the graphical desktop is up and running, Orca is active, and the Orca Preferences dialog has focus. The Orca Preferences dialog is a multi-page dialog with several pages that allows you to configure your settings.
Ubuntu ships with a selection of high contrast themes, complete with custom icons and mouse cursors. To activate a new theme, press System -> Preferences -> Appearance.
The Gnome desktop environment supports several options for modifying the behavior of the mouse and keyboard. The modifier keys (Shift, Ctrl and Alt) can be made Sticky so that when they are pressed once they remain active until the next key is pressed, making it possible to write upper case character or use keyboard shortcuts while only pressing one key at a time. Other features include Slow Keys and Bounce Keys which control the reaction rate and repeat rate of keys and Mouse Keys which allow the numeric keypad to be used to control the mouse cursor. These features can be activated on the Keyboard Accessibility panel (from System -> Preferences -> Keyboard). On-screen Keyboard Ubuntu includes the onBoard on-screen keyboard, a lightweight text-entry application, extensible through macros, scripts and custom layouts. Also available is Gnome On-screen Keyboard (GOK) which, in addition to basic text entry, also provides facilities for controlling the entire desktop behavior through the on-screen keyboard by gathering information about other applications and sending them control signals through the Gnome assistive technology framework AT-SPI. MouseTrap MouseTrap permits people with movements impairments to access the computer. Mousetweaks For users that cannot click with a hardware button, there is an utility named Mousetweaks that enables them to perform the various clicks by software. Mousetweaks offers the following new features to the user:
- Systemwide software click, usually called dwelling
- Systemwide simulated right click through a click and hold of the left button (of course, for left-handed mouse users, the terms left and right have to be inverted)
- Area on the panel to temporarily lock the pointer (provided by a panel applet)
It uses image processing to translate the user's head movements into mouse events (movements, clicks) which allow users to interact with the different desktops managers and applications. Dasher Dasher provides an intuitive way to enter text without using the computer keyboard. It uses the head-mouse or eyetracker.
It is possible to control applications using voice commands. Julius speech recognition engine can be used to recognize voice commands and execute pre-set commands. Here is simple tutorial to get you started. At recent UDS 2009 a proposal for Voice Driven User Interfaces was discussed.
Activating preinstalled tools
If you install the Ubuntu system after booting the Ubuntu Desktop CD with an accessibility option as described above, those features will also be preconfigured to start by default on your newly installed system. The most common accessibility tools such as Orca and onBoard are preinstalled on any standard Ubuntu system and are easy to activate. The screen reader, magnifier and on-screen keyboard are all activated using the Gnome Assistive Technology Preferences panel, Found in the System Menu under Preferences.
Using Onboard and Mousetweaks at GDM
For users of Ubuntu 7.10 and above, it is possible to configure GDM so that onboard and mousetweaks are available during the GDM session. This HowTo contains detailed explanations about how to configure GDM to make onboard and mousetweaks available and how to start them during the GDM session.