A study has revealed that songbirds can be trained to understand non-language aspects of human speech. The study proved that zebra finches have the capability to show even more sensitiveness to prosodic variations, like changes in the pitch, volume and duration of spoken syllables, than humans.

It is now believed that the evolution of structured language might have been predated by prosodic features of vocal sounds. The study involved birds that were trained to respond to patterns of human speech syllables. Researchers placed a loudspeaker above their cage so that the birds can listen to sounds.

The birds were tasked to peck a specific key or take no action depending upon the sound. The birds were offered a food reward for a correct response, while 15 seconds of darkness was all they got for an incorrect response.

Both a male and a female speaker uttered two different sequences of four naturally spoken syllables. Also, researchers altered pitch, volume or duration to stress the first or last syllable in each group so as to add prosodic patterns typical of human speech.

The finches performed brilliantly as they not only recognized the changing patterns, but they were able to apply their learning to sequences consisting of new syllables as well.

The findings of the study provided strong evidence that zebra finches are sensitive to the same prosodic cues known to affect human speech perception, said the scientists.

Michelle Spierings, from Leiden University in the Netherlands, led the team of scientists and he reported the findings in the journal Proceedings of the Royal Society B.

"Our results show that sensitivity to prosodic cues is not linked to the possession of language and might have preceded language evolution, possibly originating from a pre-existing sensitivity to meaningful variation in pre-linguistic communicative sounds", he added.