Charles Darwin once said that ‘the sounds uttered by birds offer in several respects the nearest analogy to language’.
Now researchers from Canada suggest that Darwin may have been on the right track.
Their research has revealed that songbirds and humans share how they produce and perceive sounds.
The study suggests that human speech and music may be rooted in biological processes shared across a range of animal species.
This implies a ‘universal grammar’ encoded in some animals that has evolved in humans to help us learn to communicate by favouring certain motifs.
Songbirds and humans share how they produce and perceive sounds. Researchers found that zebra finches (file photo) naturally learn to produce particular kinds of sound patterns over others
Researchers at McGill University in Montreal, Canada, tested how zebra finches learned songs to better understand what drove their song choices.
The team individually tutored young zebra finches with songs consisting of five acoustic elements arranged in every possible sequence.
The birds listened to each version of the sequence the same number of times and in a random order.
This meant each finch had to individually ‘choose’ which sequences to produce from the selection of birdsong.
In the end, the song patterns that the laboratory-raised birds preferred to sing were very similar to those observed in natural populations of birds.
For example, like wild zebra finches, birds tutored with randomised sequences often placed a ‘distance call’ – a long, low-pitched vocalisation – at the end of their song.
Other sounds were much more likely to appear in the beginning or middle of the song.
For example, short and high-pitched vocalisations were more likely to be sung in the middle of a song than at the beginning or end of song.
This matches patterns across human languages and in music, in which sounds at the end of phrases tend to be longer and lower in pitch than sounds in the middle.
‘These findings have important contributions for our understanding of human speech and music,’ said Professor Caroline Palmer, a psychologist at McGill who was not involved in the study.
‘The research suggests that statistical learning alone – the degree to which one is exposed to specific acoustic patterns – cannot account for song (or speech) preferences.
The patterns favoured by the zebra finches resembled those frequently observed across human languages and in music. The study suggests that human speech and music may be rooted in biological processes shared across a range of animal species (stock image)
‘Other principles, such as universal grammars and perceptual organisation, are more likely to account for why human infants as well as juvenile birds are predisposed to prefer some auditory patterns.’
Linguists have long found that the world’s languages share common features, termed ‘universals.’
These features encompass the structure of language, such as word order, as well as finer acoustic patterns of speech, such as the timing, pitch, and stress of utterances.
Some theorists, including Noam Chomsky, have suggested these patterns reflect a ‘universal grammar’ built on innate brain mechanisms for language learning.
Similarly, vast surveys of zebra finch songs have shown a variety of acoustic patterns found universally across populations.
The new study ‘provides insights on universals of vocal communication, helping to advance our understanding of the neurobiological bases of speech and music,’ Dr Denise Klein, a neuroscientist at the Montreal Neurological Institute who was not involved in the research, said.