Birds and human voices share acoustic patterns
· BehindLines newsroom
The vocalizations of birds and the human voice share certain acoustic patterns. A study published on 29 October in Science compares the vocalizations of 367 bird species with speech and song in 52 human languages, according to the presentation by the American Association for the Advancement of Science. It looks for regularities in how sounds are organized, without claiming to translate what animals say.
The similarities include small changes in pitch, regular rhythms and the lengthening of sounds at the end of phrases. McGill University, some of whose researchers took part in the work, also describes these three characteristics in its presentation of the study.
The team included groups that learn their vocalizations and others that do not learn them by imitation. This choice makes it possible to test whether learning alone is enough to explain the resemblances with humans. The results do not support that explanation on its own: the patterns are also found in birds without vocal learning.
The authors instead consider, among the leads to be examined, shared constraints on sound production and on the control of movements. Breathing, anatomy and the size of the animals may also influence the sequences produced. These mechanisms remain subjects for verification; a recorded resemblance does not allow a cause to be chosen automatically.
The distinction matters for the reader: recognizing a similar rhythm in two recordings shows neither an identical meaning nor mutual understanding. Comparing sound parameters and understanding a communication are two different questions.
This research thus provides a basis for widening the comparisons and designing experiments. The presentations by McGill and by the publisher concern the same work, and are not two independent replications. Further tests will be needed to establish what the resemblances reveal about the mechanisms of the voice, beyond the familiar impression of musicality in birdsong.