ChaCha's voice search comes out on top when matched against Google and Yahoo's voice-enabled search applications on the iPhone, according to a performance analysis by MSearchGroove.

Both the Google Mobile App with Voice and Vlingo for iPhone scored low performance rankings for accuracy and voice recognition. ChaCha credits its human guides with much of its success claiming that social search, a process that combines human preference and judgment into the computer's algorithms, delivering relevant search results.

"Mobile devices are for conversation -- and that means both voice and text conversations," said Susan Marshall, vice president of marketing at ChaCha, Carmel, IN.

"While teens send about 3,000 text messages per month as compared to making 191 calls per month, voice is still a common method of communication by a large segment of the population, particularly the over 18 crowd," she said.

"To provide the best possible mobile search user experience, we need to provide both voice and text search in an easy and accessible way."

ChaCha is a mobile search service that allows mobile phone users to text or call with a question or query, which is interpreted by human guides and then a generated answer is sent back to the user.

In the category of queries asked as questions, ChaCha accurately interpreted 94.4 percent of the tests and delivered accurate search results in 88.9 percent of cases.

On the other hand, Google's voice recognition technology only interpreted 16.7 percent of queries accurately during testing and delivered accurate results 22.2 percent of the time.

Vlingo for iPhone's interpretation of voice queries came in at a respectable 72.2 percent however the answers it delivered via Yahoo were only accurate 27.8 percent of the time.

"ChaCha lets users ask questions in natural language, as if they were talking to a smart friend and ChaCha understands because there is a person who is interpreting the meaning of the question and providing an answer," Ms. Marshall said.

"No computer is smart enough to duplicate the human brain yet in mobile search," she said.

The researchers from MSearchGroove evaluated the overall performance of the voice-enabled mobile services from ChaCha, Google and Vlingo for iPhone with Yahoo by asking a series of 18 queries from six typical mobile search categories such as navigation, direction, local information, general information, social and long-tail.

In every query, the researchers evaluated performance characteristics such as response time, results accuracy, voice recognition accuracy, number of results received, key taps required, relevancy of results, location awareness, use of advertising and presence of other value-added features.

The research also included two rounds of testing for both natural language (question form) and search by keywords.

ChaCha specializes in natural language search yet still outperformed Google and Vlingo delivering accurate results in response to keywords, which has traditionally been a strong point for Yahoo and Google.

"As the demand for mobile advertising increases and revenue from well-designed mobile services increases, you will start to see product developers and designers build mobile services that really work well," Ms. Marshall said. "The money is there.

"But until Web sites are redesigned for the special circumstances of mobile use, and search is made brain-dead simple and powerful, the mobile advertising market will not prosper like it should," she said.