Verdict: A superb product that makes voice recognition even easier and more accessible than Dragon's NaturallySpeaking Preferred 4.

ViaVoice has been the dominant player in the speech-recognition market for several years now, but was recently outclassed by Dragon's NaturallySpeaking Preferred 4. In fact, Preferred 4 was something of a landmark product, providing excellent recognition rates after just ten minutes, and it deservedly walked away with a PC Pro Recommended award - a first for speech-recognition software.

Traditionally, training times were one of the biggest problems for speech recognition. Introducing the computer to your voice could take almost an hour, and initial results were disappointing. With this edition of ViaVoice, IBM is following Dragon's example, slashing training times and aiming for good results from the start.

The first thing you'll notice after you've installed ViaVoice is Woodrow, a cartoon character in the style of Microsoft's Office Assistants. This may be too patronising for some people's taste, but these 'agents' do help to make the process more accessible to the voice-recognition novice.

Once Woodrow has introduced himself and the product, the next step is the enrollment itself. You choose from a selection of passages, read for around ten minutes, and it takes ViaVoice up to 15 minutes (four on the 550MHz Athlon machine we used for testing) to create your voice profile; and then comes crunch time - your first dictation.

The accuracy you manage will depend on many things, including how well you trained the software, the clarity of your enunciation, the speed of your machine (ideally, this should be a Pentium III or Athlon to take advantage of the streaming SIMD extensions), the quality of your sound card, and whether you position the microphone in its optimum position. It also depends on the quality of your microphone, but ViaVoice includes its own headset and a good mike.

To ensure the software packages were on even ground, we tested ViaVoice, Voice Xpress and Dragon NaturallySpeaking on the same PC, against the same background noise, and on five different passages of text. But, unfortunately, ViaVoice doesn't have the ability to transcribe WAV files, so we couldn't use the same recording with which we tested NaturallySpeaking and Voice Xpress, but the results were conclusive nonetheless. In a total of 1,000 dictated words, ViaVoice misrecognised just 79, giving it a superb recognition rate of 92.1 per cent. This compares to 90.2 per cent from NaturallySpeaking, and 83 per cent from Voice Xpress.

Although initial recognition rates are the most important indication of speech-recognition software's quality, the good news is that you can and must continually train it to improve performance. The best way to improve recognition, apart from ensuring you speak in a clearer voice, is to correct any mistakes the software makes during or after dictation. This is easy to do - just say 'Correct' followed by the word you want to correct, and this brings up the Correction window. The re-recognised words are then incorporated into your voice profile.

Another way of improving recognition is to build your own vocabulary. For example, if you use technical words in reports, you can instruct ViaVoice to examine these documents and add any new words to its already impressive 100,000-word lexicon. ViaVoice already knows many British place names and public figures, but this is one area where Dragon retains its edge.

With ViaVoice Pro, you can dictate into any Windows application that accepts text, as well as using IBM's voice-enabled word processor SpeechPad. The biggest advantage of using SpeechPad is performance; voice recognition requires as much RAM as possible, so reducing the number of open applications can only help matters. However, most people will prefer to dictate straight into Microsoft Word, and it's here that ViaVoice shows its weakness, as there's a distinct lag between your instruction and the actual event.

As well as dictating, you can also use ViaVoice Pro for navigating around your Desktop - for example, say 'Open Control Panel' and the Control Panel will open. It also includes support for Web browsing, with the command 'Surf the Web' launching Internet Explorer. You can then name a Web site in your Favourites folder, and it will jump to it, but it's a painful process to spell out the Web address of a new site. It's quite easy to follow hyperlinks, however, as you just say the first few words, and ViaVoice makes it equally easy to follow links embedded in graphics by numbering them - you then just say the number.

IBM's pricing policy is almost identical to Dragon's, with this professional edition costing £101 and the standard version a more reasonable £34. You lose features like Web browsing, navigating around the Desktop and, more importantly, direct dictation into applications other than SpeechPad.