The digital voices that read aloud text and system messages have been vastly improved. Lion ships with several basic default voices, but you can download a lot more, including non-English voices, and dialect English voices for British, Scottish and Irish. They haven't removed the silly voices either, like Cello and Bubbles. I'm fond of Daniel (British English) and Fiona (Scottish English).
To install additional voices:
- Open System Preferences
- Click Speech
- Click the "Text to Speech" tab
- Choose Customize from the "System Voices" popup.
- Preview the voices you're interested in by selecting a voice and clicking Play.
- Check the boxes of voices you would like to install.
- Voices that need to be downloaded will display a yellow triangle and a note that "This voice will be automatically downloaded." Keep in mind that these voices average about 500 MB each in terms of the space they take up on your hard drive.
- Click OK when you have finished selecting voices.
- You'll see a dialog that names the voice, tells you how large the file(s) will be, and asks if you're sure you want to download the voice," with Install and Cancel.
- If you click Install, Software Update will launch, and download and install the voices for you.
To use your new voices, launch an application that supports Apple's Text to Speech (TextEdit, Safari, or Mail, for instance). Select some text, and then control-click the selection and choose "Start Speaking" from the Speech submenu.