Google has filed a patent in the USA covering voice search technology, potentially allowing users to search the internet vocally.The patent, filed on Tuesday 11 April, covers a number of aspects relating to voice recognition technology, including specific elements of how a search would be constructed from a spoken command.This patent is the first step in the process of Google offering a voice search service to users, although such a service is unlikely to be made available in the near future. Google has made a number of attempts to branch out from internet searching, but the vast majority of its revenues come from advertising alongside searches. The IT giant’s stock price has recently suffered under speculation that the online advertising search market is maturing.“To satisfy the average user, a voice interface to a search engine must recognise spoken queries, and must return highly relevant search results. Several problems exist in designing satisfactory voice interfaces. Current speech recognition technology has high word error rates for large vocabulary sizes,” the authors stated in the background section to the patent.Summarising their invention, the authors went on to describe “a method that provides search results includes receiving a voice search query from a user; deriving one or more recognition hypotheses from the voice search query, each recognition hypothesis being associated with a weight; constructing a weighted boolean query using the recognition hypotheses; providing the weighted boolean query to a search system; and providing results of the search system.”Google co-founder Sergey Brin and three others are credited with the invention of the voice search technology .Google released a calendar and personal organiser service last week, the latest in a long line of services outside its core search business, which also include Google Earth, Google Video, and the popular Gmail email service.