For years, Mac users have waited for an application that would let them dictate with natural speech and control their Macs by voice--abilities that, until recently, have been available only in Windows. Previous versions of IBM's ViaVoice allowed Mac users to dictate, but ViaVoice for Mac OS X harnesses the power of the new operating system, promising to bring freedom from the keyboard and mouse. (See " Listen Up," June 2000, for an in-depth discussion of voice technology.) That's more than cool: it's critical for people who have limited use of their arms because of an injury or a disability.

But although ViaVoice is a fine dictation program, it will disappoint users who are looking for full-featured command-and-control capabilities.

Getting Started

Installing ViaVoice takes a little time up front. You must spend about 20 minutes setting up the included USB headset microphone, testing sound levels, and reading a passage of text. (New in this version is the ability to analyze a set of documents to learn the vocabulary you typically use.) Then you're ready to go. ViaVoice lets you dictate into any Mac OS X or classic-Mac OS application, but you'll be able to work most efficiently in SpeakPad, ViaVoice's SimpleText-like text editor.

Dictation and Editing

You'll get respectable accuracy from ViaVoice's SpeakPad right away. Depending on the difficulty of a document's vocabu-lary and punctuation, SpeakPad's accuracy rate was between 88 and 95 percent in our tests. And as ViaVoice learns your voice, accuracy improves.

You can dictate into Word X with comparable accuracy (an improvement over the performance of ViaVoice Enhanced Edition), but the pace is slower. To avoid this, dictate longer passages in SpeakPad and then use ViaVoice to transfer your efforts to a word processor or an e-mail program. This works surprisingly well, but it is an inconvenience.

Unfortunately, correcting mistakes in ViaVoice isn't as easy as it could be. You can make corrections by voice only in SpeakPad. (This is a step back from ViaVoice Enhanced Edition, which let you make corrections in AppleWorks and Microsoft Word.) If you dictate a letter into Word, you'll need to use the keyboard to fix goofs. ViaVoice also can't learn and improve from corrections you make by hand.

Even in SpeakPad, correction lacks some niceties. There are few shortcuts, such as the ability to correct a misinterpreted phrase by saying "Correct this" right after the text appears on screen. Instead, you must say the words themselves or select them with the mouse and then choose from a list of possible fixes. You do have the ability to play back a section of text after the fact so you can figure out what you said--a big help when you need to correct errors that are hard to decode.

SpeakPad gives you some basic tools for editing your text. You can italicize words by saying "Italicize this," for example. But the program lacks most of the editing options standard to Windows speech-recognition programs such as Dragon NaturallySpeaking. For example, you cannot change text size or style by voice.

And the program has some bugs. During our tests, the microphone sometimes stopped responding, and SpeakPad quit unexpectedly several times.

Command-and-Control Limitations

Sadly, what should be the breakthrough feature of this product--the power to control by voice almost everything you can do with your Mac's mouse or keyboard--is disappointingly limited. Unlike other speech-recognition programs--from the venerable Dragon PowerSecretary for Macintosh (discontinued in 1998) to Dragon NaturallySpeaking for Windows--ViaVoice does not give you built-in access to every menu and every key on the keyboard. For example, you can't say "Click File" to call up the File menu and then say "Click Print Preview" to open that window.

Instead, ViaVoice includes voice shortcuts for some common actions. You can open many programs by voice--for example, saying "Open iMovie" does just that. (But there are inconsistencies: instead of saying "Open," you say "Launch" to start Microsoft Word.) You can also press some keys by voice no matter where you are, including the enter, delete, and tab keys; all the function keys; and the arrow keys.

If you want to go further than this, you must make the shortcuts yourself, by using ViaVoice's keyboard-shortcut editor, KSD (Keyboard Shortcut Dictionaries) Editor, or by writing a custom AppleScript. It's fairly easy to create a Word macro and then use KSD Editor to create a voice command, but the program would have been immeasurably enhanced if IBM had done this work for us.

One place speech-technology novices can get an inkling of the power of command-and-control features is with Microsoft Internet Explorer. Almost every option in the program's menus is accessible by voice.

Macworld's Buying Advice

If you currently use the OS 9 version of ViaVoice, there's no question that this upgrade is reasonably priced ($20) and good for dictation--and it's the only speech-recognition and command-and-control option currently available for OS X. If you like to tinker, you may enjoy seeing how far you can take ViaVoice with keyboard shortcuts and AppleScripts. There's power to be tapped here if you're willing to put in the time and effort. But if you're injured or disabled, ViaVoice may not be ready for you, unless you have a friend willing to enter the necessary scripts and shortcuts for you.