Nuance Communications claims the microphone will soon be just as valuable as the keyboard to PC users. Its Dragon NaturallySpeaking 9 speech-recognition software, released this month, "promises to transform the way people use their PCs," according to Nuance. It's a fragile promise, though it does hold some truth.

"The premise of Dragon NaturallySpeaking is not to encourage people to tie their hands behind their backs or throw away their keyboard and mouse, it's to find an optimal mix of modalities that makes you the most productive you can be with your PC," says Matt Revis, Nuance's director of product management for dictation solutions.

When Revis' exact comments were read to a PC equipped with the software, it transcribed this: "The premise of Dragon NaturallySpeaking is not to encourage people to tie their hands behind their backs Withrow weighted keyboards or mouse, it's to find an optimal mix of modalities that makes you the most productive you can be with your PC."

Not perfect, and not enough to make keyboards obsolete. But close enough for a lot of uses, including the dictation-intensive legal and health care industries. Dragon NaturallySpeaking 9 boasts accuracy levels up to 99%, according to the company, a 20% improvement from the last version.

A number of vendors sell speech-recognition products, including heavy hitters such as IBM.

When a users speaks in slow, meticulously annunciated tones, Dragon performs very well: It recognized and transcribed the first paragraph of the product's press release word for word.

But talking to one's PC doesn't always make sense, even if Dragon's transcriptions typically do. Just as mobile phone conversations disrupt movie theaters, conversing with computers can be awkward or bothersome in some workplaces.