SAN FRANCISCO: Google is reportedly weighing into the Internet voice search arena with a free application that lets iPhone users surf online by speaking queries.

An article said the software could be available at iTunes online store as early as Friday. Google will be stepping into an arena with rivals Microsoft and Yahoo, which already let people using "smart" phones scour the Web with spoken queries.

The Internet powerhouse already offers a toll-free GOOG411 telephone service in the United States that people can call and speak to a computer system that fetches contact information they seek. The iPhone application will be Google's first foray into voice-based Internet search.

Google in 2006 received a US patent for a system that "provides search results from a voice search query." "Current speech recognition technology has high word error rates for large vocabulary sizes," Google wrote in the patent application.