Birdsong and the human voice share several acoustic patterns, including predictable rhythms, modest shifts in pitch and a tendency to extend the final sound of a phrase, according to a study published in the journal Science on October 29.
The researchers analyzed more than 74,500 vocal elements from about 5,900 songs across 367 bird species. They compared these with more than 15,000 elements of human speech and singing, arranged into over 800 phrases in 52 languages.
The study brought together researchers from institutions including McGill University in Canada and Imperial College London in the United Kingdom. Some bird recordings came from Xeno-canto, a platform that collects animal recordings contributed by people in different countries. Publicly available field recordings allowed the team to compare vocalizations across a broad range of species.
The researchers also examined whether the ability to learn vocalizations was linked to the shared patterns. Some birds, including songbirds and hummingbirds, learn vocalizations by listening to others. In groups such as suboscines and nightjars, vocal production depends predominantly on innate mechanisms.
Although human speech and singing involve learning, the results showed no systematic link between vocal learning and the acoustic patterns examined. The findings therefore suggest that learning is not necessary for these similarities to emerge.
The comparison does not show that humans learned to speak or sing by imitating birds. Instead, the results point to shared patterns and are consistent with the possibility that constraints or mechanisms involved in producing vocal sounds can lead different species to develop similar solutions.
The research contributes to biomusicology, a field that draws on evolutionary biology, neuroscience and music studies to investigate the foundations of musicality. Earlier work has also compared bird vocalizations with musical techniques. A 2021 article on the mockingbird described gradual changes in timbre, pitch and duration that resemble variations on a theme, while cautioning against treating the bird as composing with the same intentions as a human musician.
The findings also offer a way to listen more closely to birdsong: repeated sounds, pauses and changes in a call may become easier to notice when heard as organized phrases. They reveal points of acoustic overlap without making bird vocalizations equivalent to human music.
Sources: Folha Ilustrada.