127. Talk to Your Computer and Have It Talk Back to You (VoiceOver)  SEE ALSO 129 Choose How the Computer Alerts You
127. Talk to Your Computer and Have It Talk Back to You (VoiceOver) 
Users with difficulty seeing, reading small text, or navigating using the mouse might find it useful to configure Mac OS X to use its advanced spoken user interface, known as VoiceOver . This system involves both text-to-speech synthesis (having the computer speak the text of alert dialog boxes, word-processing documents, web pages, and the names of elements of the system that you interact with in everyday operation and navigation), and a comprehensive keyboard navigation system that makes using the hard-to-see mouse unnecessary. Even fully sighted users can take advantage of Mac OS X's convenience features related to VoiceOver technology. There are a lot of configurable options in the Speech Preferences pane that control the many fine-tuning options for these features, such as enabling the system to speak the text of alert messages and selected text, or activating the Mac's built-in voice recognition technology (allowing you to speak commands to the computer and have it respond just as though you were using the mouse or keyboard). You can also choose the spoken interface's voice from many possible "personas" and control its speed, pitch, and volume, even on the fly. VoiceOver is a sophisticated vocal interface sewn into the very fabric of Mac OS X Tiger, and is designed to tailor itself to your needs or the needs of a user that you're assisting (for example, one with learning disabilities ). This book cannot provide a full demonstration of its capabilities; the best way to learn how to use VoiceOver is by trying it yourself. This task introduces you to it by showing you how to activate it and adjust its more important options. | 1. | Enable Speech Recognition Imagine telling your computerin your own natural voice"Get my mail." Imagine the computer firing up Mail, checking for new messages, and waiting for your next voice command, whether it be "Quit this application" or "Tell me a joke." Sound like science fiction ? Well, it's notit's just life with a Mac.  NOTE Most Macs have built-in microphones that can be used in voice recognition; iMacs, iBooks, and PowerBooks have a small hole next to the display that marks where the microphone is. Power Macs have a line-in jack for an external microphone. Mac OS X also accepts sound input from various FireWire cameras , such as Apple's iSight. Open the Speech Preferences pane (click Speech in the System Preferences application). Click the Speech Recognition tab, if it's not already selected. Click the On radio button labeled Speakable Items . A round, floating feedback window appears, with the word Esc in its display oval; this indicates that you must press and hold Escape to make the computer listen to you. You can change this default behavior under the Listening tab, where you can select a different listening key, choose whether the listening key toggles listening on and off or acts as a "push-to-talk" button, or even define a spoken preamble to make sure the computer knows you're talking to it. "Computer, get my mail," you might say. You can even define a different name for your computerthe Mac will recognize the name as long as you speak it in a clear voice. Just type the name in the Name field, if you have selected to have the listening key toggle listening on and off. | | 2. | Give Your Computer a Command Click the down arrow in the round listening window, and select Open Speech Commands window from the menu that appears. This window lists all the built-in speakable commands, and shows you the history of your previous commands. NOTE The Speech Commands window need not be open for voice recognition to work, but it shows you all the available speakable commands, so until you've memorized the commands you want to use, it's a good idea to keep the window open for reference. Hold down Escape (if you are still using the default, "push-to-talk" configuration) and speak the text of any command listed in the Commands box. If the Mac recognizes your command, its text appears in the history box, and the command is executed. If the Mac didn't recognize the command, nothing will happen; just try again, speaking as clearly as you can. TIPS Tell the computer to "tell me a joke," if you like knock-knock jokes. Also try using voice commands to play the Chess game found in the Applications folder. So much for Solitaire, eh? You can define new commands for any application; just give the command "define a keyboard command" when that application is active, and a window appears that lets you associate a spoken word (which it will interpret as you type it) with a keyboard shortcut that the application recognizes. Try setting up "Play" and "Pause" commands for the QuickTime Player this way, using the Space and Return key commands (to keep them separate). | | 3. | Choose a System Voice
VoiceOver is the general name of the text-to-speech interface technology in Mac OS X, encompassing a full spoken user interface to aid those with disabilities, as well as a number of convenience features to make anyone 's life easier. Without fully enabling the assistive features of VoiceOver, you can tap into its capabilities to have Mac OS X alert you with a certain spoken word or phrase whenever an alert box or sheet appears.
Mac OS X comes with many different "voices" you can use to read your text; Victoria , the default, is probably the most natural-sounding one. You can experiment with many others, however; some are "novelty" voices, but many are designed to be as natural-sounding as possible. The System Voice is the default voice that Mac OS X will use when rendering text to speech, unless you specifically choose otherwise within a given feature (such as VoiceOver).
Click the Text to Speech tab in the Speech Preferences pane. Pick your favorite voice from the System Voice drop-down menu, using the Play button to preview how each voice will sound.
| | 4. | Have the System Announce Alert Conditions Mac OS X can grab your attention when system alerts occur by reading the title of the alert in the voice of your choice, after a specified preamble or by itself. Select the Announce when alerts are displayed check box and then click the Set Alert Options button to choose the phrase (if any) for Mac OS X to speak before the alert text. You can select a single specific phrase, choose a random or sequential phrase, or even add new phrases of your own, such as "Hey, you!" TIP This is text-to-speech synthesis, so you can specify a new phrase by clicking the Add button in the Edit Phrase List pop-up window and typing the phrase. Mac OS X reads the text you type in the voice you've selected. Use the Delay slider to specify how long the system should wait before speaking the alert text. This can be helpful if you want to be able to respond to alerts yourself within the first 30 seconds or so, but if you also want the system to remind you more forcefully with a spoken alert if you're really busy and have ignored the condition until that time has elapsed. If you dismiss an alert dialog box right away, the system won't speak its text. Another form of alert is when an application running in the background requires your attention; this often occurs when an iChat buddy sends you a message or Mail is temporarily unsuccessful in logging in to your email account, to take two common examples. Select the Announce when an application requires your attention check box to have Mac OS X alert you to these conditions as well. | | 5. | Speak Selected Text
Select the Speak selected text when the key is pressed check box to make Mac OS X speak any block of text in the system that you have selected, such as the contents of a text file or an email message, when you give a specified keyboard command.
Click the Set Key button to define the key used to make the system speak the selected text. A dialog box appears that allows you to press the key combination you want to use to trigger speech; a good key to use is one of the unused function keys, such as F8 . Additionally, Mac OS X encourages you to combine this key with one or more modifier keys, such as Shift or Control . Press the key combination you want to use and click OK . (If you specify a single key without modifiers, Mac OS X prompts you to make sure you really want to bind a single key this way; it's generally advisable to use at least one modifier key to prevent accidentally triggering the text-to-speech function.)
| | 6. | Enable VoiceOver Navigation
To take Mac OS X's spoken user interface to the next level, enable the full assistive features of VoiceOver. Open the Universal Access Preferences pane (click the Universal Access icon in the System Preferences application), and click the Seeing tab if it's not already selected. The topmost option is VoiceOver ; click the On radio button to turn on the assistive vocal navigation system.
You will immediately seeor rather hearhow VoiceOver works. The system speaks a brief welcome message and a set of terse phrases that describe what part of the system is currently active: namely, the System Preferences application, the Universal Access window, and the Back button (the first control in the window). This text is spoken using a voice that may or may not be the same as your System Voice (it's set independently).
Move from application to application, clicking various controls and windows ; observe how VoiceOver follows your movements and vocally reports what you're doing. This level of VoiceOver functionality can itself provide great assistance to users with vision impairment , enabling them to use the computer more easily than ever before. However, there's still a lot more that can be configured in VoiceOver.
| | 7. | Fine- Tune VoiceOver Behavior
In the Universal Access Preferences pane, click the Open VoiceOver Utility button; alternatively, launch VoiceOver Utility from within the Utilities folder. This utility allows you to fine-tune the behavior of VoiceOver to an extensive degree. For example, in the Verbosity tab, you can control how much of your typing and word-processing commands are reported by VoiceOver. Change the While typing speak drop-down menu to Every Word to make VoiceOver read everything you type back to you in a more useful manner than the default Every Character . You can also change the greeting text that VoiceOver speaks when it's first activated, and enable a feature that speaks the text immediately under the mouse cursor when you hover it there for a brief time (the length of delay is configurable using the slider).
The Navigation tab lets you experiment with many check boxes that control subtle behaviors of the system having to do with navigation, cursor tracking, and text selection tracking. Feel free to change these settings until you're comfortable with how VoiceOver reacts to your computing habits.
In the Voices tab, choose the default voice that VoiceOver should use when speaking its text; you can even set a different voice for various different aspects of the system, so that (for example) the content of windows can be spoken by a different voice or at a different rate than the titles or attributes of the windows.
The Display tab gives you additional assistive features, such as the Caption Panel , a floating semi-transparent window that reflects the phrases that VoiceOver speaks as you move through the system, and which can be dragged to any convenient place on the screen and resized using the sliders (or by dragging its lower-right corner). The VoiceOver cursor is a rectangle that highlights the currently active control or window, and its contents can be magnified to any comfortable size , further assisting users with impaired vision in getting around the system. The VoiceOver Menu , which you will see more of in the next step, is a floating command navigator that gives you access to all of VoiceOver's extensive keyboard commands; it can be summoned by pressing Control+Option+F7 , and its size can be controlled using the VoiceOver Menu Magnification slider.
Finally, the Pronunciation tab lets you define certain unusual strings of text (such as acronyms and emoticons or "smileys") that VoiceOver cannot reasonably be expected to pronounce properly. Mac OS X can read practically the entire English dictionary, and a lot of things that aren't in it as well; but if there's some word or construct that it just isn't getting right, you can enter a "substitution" for it by describing to the system how it should pronounce the word phonetically. Several examples are already present to show you the idea.
If your VoiceOver settings become too confused , you can click the Reset button at any time to revert to the default settings of the vocal navigation system.
| | 8. | Use VoiceOver and the Keyboard to Navigate
VoiceOver is intended not just to read the interface to you, but to allow you to easily interact with the interface using some special keyboard commands, rather than the hard-to-see mouse cursor.
There is a comprehensive variety of keyboard commands that are used to move between windows, open and select from menus , click the mouse, and do everything else that normally requires sharp vision. These commands can be accessed using the VoiceOver Menu , which is summoned by pressing Control+Option+F7 . Use the keyboard to move up and down through this floating menu and left and right through the menu hierarchy. Each command (under the Commands submenu) is labeled with the key combination necessary to perform basic computing tasks , as are the navigation keystrokes under the Navigation submenu. A Keyboard Practice option is available to let you become more familiar with the spoken names of every key on the keyboard.
At this stage, practice is the best path forward. Use the VoiceOver Menu to discover new keyboard commands, and use the extensive VoiceOver Help option (choose Help from the VoiceOver Menu) to see a comprehensive tour of the VoiceOver vocal navigation system. Once you have practiced using VoiceOver for a while, you won't need to rely on the mouseor even your eyesfor a single major aspect of using your Mac.
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