ArticlePNAS nexus2023
Wild orangutans can simultaneously use two independent vocal sound sources similarly to songbirds and human beatboxers.
Article in PNAS nexus, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
5 citing papers in PubMed, 8 citations in OpenAlex.
- Twice times two: Dual mechanism for double rhythmic meter in orangutans and the evolution of human song.iScience · 2026Article
- Generative vocal plasticity in chimpanzees.iScience · 2025Article
- Vocal Learning Versus Speech Evolution: Untangling a False Equivalence.Ecology and evolution · 2025Article
- Investigating the role of the left inferior frontal gyrus in language evolution: insights from comparative neuroscience.Frontiers in human neuroscience · 2025Review
- Open plains are not a level playing field for hominid consonant-like versus vowel-like calls.Scientific reports · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 1 institution in 1 country.
Funding
Abstract
Speech is among the most complex motoric tasks humans ever perform. Songbirds match this achievement during song production through the precise and simultaneous motor control of two sound sources in the syrinx. Integrated and intricate motor control has made songbirds comparative models par excellence for the evolution of speech, however, phylogenetic distance with humans prevents an improved understanding of the precursors that, within the human lineage, drove the emergence of advanced vocal motor control and speech. Here, we report two types of biphonic call combination in wild orangutans that articulatorily resemble human beatboxing and that result from the simultaneous exercise of two vocal sound sources: one unvoiced source achieved through articulatory maneuvering of the lips, tongue, and jaw as typically used for consonant-like call production, plus one voiced source achieved through laryngeal action and voice activation as typically used for vowel-like call production. Orangutan biphonic call combinations showcase unappreciated levels of, and distinct neuromotor channels for, vocal motor control in a wild great ape, providing a direct vocal motor analogy with birdsong based on the precise and simultaneous co-control of two sound sources. Findings suggest that speech and human vocal fluency likely built upon complex call combination, coordination and coarticulation capacities that involved vowel-like and consonant-like calls in an ancestral hominid.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.