Boston ? For now, something like “Call Mom” is the most advanced voice command that most cell phones can handle. A maker of speech-recognition software for personal computers hopes to change that.

Nuance Communications Inc. is trying to line up wireless carriers for a new service allowing hands-free, speech-to-text messages or e-mails of nearly unlimited length, as well as voice-command Web browsing and music downloads.

Nuance concedes its system – which would require connection with a remote server that has its software – is vulnerable to background noise interference. But Nuance says its technology has the same 99 percent speech-to-text conversion accuracy that the company claims for its latest personal-computer software.

A beta version is being tested by about 10 cellular carriers, and Nuance expects various features to reach the market in stages over the next year. Prices haven’t been set.