Japanese scientists say a study suggests that cats living in the same household can learn to recognize each other's names.

The finding was released by a group of researchers from Kyoto, Azabu and other universities looking into whether cats can understand human words.

They say they tested 19 household cats living with at least two others. The researchers made them listen to their housemates' names and showed them photos on a monitor -- one of a cat they live with and another of a cat they had never met. On average, the cats spent more than one second longer looking at the cat they had never seen.

The method is based on psychological testing for human babies. Babies who are shown pictures and made to listen to words at the same time tend to look at the pictures longer if they cannot understand their connection to the words. The researchers say the study suggests that the cats recognized the names of those they live with.

The researchers also used the method to test whether cats can recognize the names of their owners. They say the study was inconclusive, but suggested that the higher the number of owners and the more time spent with them, the better cats can remember the owners' names.

Takagi Saho at Azabu University said she conducted the research because she likes cats, and that the research is the first to show how deeply they learn. She concluded that cats may listen carefully to what people say, despite seeming not to do so.