One of the hidden goodies in Mac OS X is its inclusion of several different human-sounding voices paired with text-to-speech (TTS) and speech- recognition engines that can turn your Mac into a far more vocal participant in your everyday computing experience.
TTS settings are accessible through the System Preferences > Speech option. Select the Text to Speech page and choose one of the six voices presented. You can get more options if you go to Show More Voices in Snow Leopard or Customize in Lion.
You can easily decide when you want your computer to pipe up, and not: Choose whether it should announce system alerts, applications demanding your attention, or simply say whatever text is selected when you press a configurable hotkey (we chose Shift-Option-c-V).
Automator includes a Speak Text action, while some third-party apps can talk too: the Growl notifications engine, for one, can speak its alerts if you set the notification type to ‘Speech’.
Switch to the Date & Time > Clock preferences panel to have the computer announce the time at regular intervals, or switch to the Universal Access > Seeing preferences panel to control VoiceOver features that speak whatever content is currently selected.
Turn VoiceOver on and off by pressing Command-Fn-F5, and configure it using the program VoiceOver Utility. VoiceOver can quickly wear out its welcome without tweaking, but for those who struggle to read onscreen content it can be a big help.
While it doesn’t offer the extensive transcribing features of a third-party product like Dragon Dictate, Mac OS X also includes voice-control features that can be useful complements to mouse and keyboard controls.
Load the Speech Recognition panel of the Speech preference, turn ‘Speakable Items’ on, then click on Settings and choose a microphone; you may find a headset-and- microphone combination offers clearer recognition. Click Calibrate… before adjusting the volume and speaking the eight sample commands.
You’ll also need to set a Listening Key – which you press to indicate to the computer that you’re about to speak a command. Click Change Key… if you want to use something other than the default (Esc) or click ‘Listen continuously with keyword’ if you prefer to use a spoken command to tell the Mac you’re about to give it a command.
You’ll see a round microphone-like icon appear onscreen whenever you activate voice recognition, and a recognised command will be displayed atop this icon. Basic commands like “Open iTunes” or “Switch to Mail” will do just what you expect, and you can customise the commands your Mac recognises by clicking on the Commands page and selecting or deselecting the particular types of content your Mac should listen for.
For example, you can switch between applications; find contact names in Address Book, iChat, iCal and Mail; use application-specific commands that are installed with certain apps; use “Front Window” to select items in whatever window has your focus; or choose options from the current application’s menu bar.
To insert a page break in Word, for example, you’d say “Open Microsoft Word”, then “Insert Menu”, then “Break”, then “Page Break”. If you want to see which commands are available in any particular application, click the Open Speakable Items Folder button.