Robotics technology has evolved over the years, but systems that can hold a sophisticated conversation with a human may still be far off.

Osaka-based Vstone Co. and professors at Osaka University are adopting a different approach: getting people to speak to more than one robot simultaneously.

They unveiled two models of robot designed for that purpose Tuesday in Tokyo. The two robots, both about 30 cm in size and weighing 900 grams, are named CommU and Sota. They are the work of professors Hiroshi Ishiguro and Yuichiro Yoshikawa and Vstone.

“One main problem of communication robots is that voice recognition technology is not very good. It has been improving greatly,” but it remains insufficient, said Ishiguro, a robotics creator famous for devising uncannily lifelike humanoid robots.

For instance, communication robots often have a hard time understanding what people are saying when there is background noise. They are also unable to respond as dynamically as a human would.

But people react differently if they speak with multiple robots, in which the robots also talk to each other. In such cases, the humans try to adjust their manner and end up feeling like they are having a genuine conversation, Ishiguro said.

This is the way adults talk to children, he said. When children do not really understand what adults are saying, adults adjust their speech and a form of conversation ensues.

In a demonstration conversation with CommU robots, two CommUs were seen fixing their head and eyes on their interlocutors and nodding.

CommU and Sota cannot understand what people are saying and are just acting out programmed conversations. They can only tell whether an individual is speaking or not.

The two robots differ mainly in the fact that CommU has greater flexibility in its joints.

The project is funded by the Japan Science and Technology Agency. Ishiguro’s team will be working on the project for several years.