![\"Ayumu](\"https:\/\/cdn.sci.news\/images\/enlarge13\/image_14659e-Ayumu.jpg\")
<\/a><\/p>\nAyumu the chimpanzee spontaneously produced long, multicomponent instrumental displays by drumming, dragging, and throwing self-detached objects. Transition and rhythm analyses revealed non-random sequencing partially resembling pant-hoot structure, predominantly isochronous timing, and a more stable tempo when using tools than with the body. Accompanying play-face and silent bared teeth expressions suggest high arousal and positive affect, supporting the idea that affective vocal expression can be externalized through instrumental sound. Image credit: Hattori et al., doi: 10.1111\/nyas.70239.<\/p>\n
In February 2023, Ayumu \u2014 a 26-year-old male chimpanzee at Kyoto University\u2019s Center for the Evolutionary Origins of Human Behavior \u2014 treated researchers to a spontaneous musical performance.<\/p>\n
He removed floorboards from a walkway and used them to drum, producing complex, structured sounds resembling vocal expressions.<\/p>\n
\u201cAyumu\u2019s drumming is nothing new,\u201d said Dr. Yuko Hattori and colleagues from Kyoto University.<\/p>\n
\u201cChimpanzees are well known for their instrumental behaviors, and are particularly adept at drumming.\u201d<\/p>\n
\u201cBut on this occasion, Ayumu\u2019s combination of drumming and vocalization \u2014 exhibiting multiple rhythmic components \u2014 was a completely novel case.\u201d<\/p>\n
Between February 2023 and March 2025, the authors recorded a total of 89 spontaneous performances by Ayumu.<\/p>\n
The recordings documented how he removed floorboards from a walkway and used them as tools to make music.<\/p>\n
\u201cIt was fascinating for me to see how the chimpanzee used tools to produce various sounds while also expressing a vocal display,\u201d Dr. Hattori said.<\/p>\n<\/p>\n
Using Ayumu\u2019s performances, the researchers examined whether vocal expression could transition into instrumental sound.<\/p>\n
They began by assessing his behavior and breaking it down into elements such as striking, dragging and throwing.<\/p>\n
They then evaluated the connections between these elements using transition analysis, determining which transitions occurred by chance and which were deliberate.<\/p>\n
Finally, they analyzed the intervals between strikes and compared the rhythmic stability of tool use with that of drumming performed using the hands or feet.<\/p>\n
The analysis revealed that the sequence of sounds produced with the tools was not random, and that the intervals between strikes were isochronous \u2014 maintaining a constant tempo, like a metronome.<\/p>\n
In fact, tool use produced a more stable rhythm than the hands or feet alone.<\/p>\n
The scientists also observed facial expressions such as the \u2018play face,\u2019 typically associated with play, indicating positive emotions.<\/p>\n
Such expressions are not typically reported in vocal displays, suggesting that emotional signals once conveyed vocally may have been externalized and developed into tool-based sounds.<\/p>\n
\u201cAyumu\u2019s performances prove that non-human primates also possess the ability to externalize vocal-like expressions with instruments,\u201d the authors said.<\/p>\n
\u201cNext, we are interested in analyzing the reactions of other chimpanzees, and the impact Ayumu\u2019s display has within his social group.\u201d<\/p>\n