Neuroscientists at McMaster University in Canada switched speakers playing bass between 8 and 37 Hz on and off during a live electronic music concert, and the audience moved 11.8% more while they were on.
The dancers did not seem to notice. In a follow-up lab test, listeners picked out the very-low-frequency speakers no better than chance, the team reported in Current Biology in November 2022.
“Music is a biological curiosity,” first author Daniel Cameron, a neuroscientist and trained drummer, said in the journal’s press release. “Why do humans like it and why do they like to move to it?”
How the LIVELab concert experiment worked
The test took place at the LIVELab, a research theatre at McMaster in Hamilton, Ontario, with 3D motion capture and a Meyer sound system. The act was Orphx, the Canadian techno and industrial duo of Rich Oddie and Christina Sealey, who have released records on labels including Sonic Groove and Hospital Productions.
“The musicians were enthusiastic to participate because of their interest in this idea that bass can change how the music is experienced,” Cameron said.
Of the 133 people at the concert, 66 agreed to take part. They wore headbands fitted with motion-capture markers and filled in questionnaires before and after the show.
The researchers added a separate set of very-low-frequency speakers that were not connected to the performers’ equipment. They turned them on and off every 2.5 minutes across the 55-minute set, so the effect could be measured as the duo moved from one track to the next.
Measured by head movement speed, participants moved 11.8% more on average while the extra bass was playing, Live Science reported from the paper.
In the post-concert questionnaires, people said they felt bodily sensations from the bass, that these were pleasant and that they added to the urge to move. They did not rate those sensations as stronger than at similar concerts.
Why bass below hearing may still reach the body
The study abstract describes the signal as “below or near auditory thresholds.” For scale, the lowest A on a full-size concert piano sits at 27.5 Hz, and much of the 8 to 37 Hz band lies under it.
Low frequencies are processed through touch and the vestibular system in the inner ear, which governs balance, as well as through hearing. Both have close links to the parts of the brain that control movement.
“Very low frequencies may also affect vestibular sensitivity, adding to people’s experience of movement,” Cameron said.
He gave a simpler version to Science News Explores: “If they’re picking up on very-low-frequency sound, they might be adding that extra bit of vigor into their movements.”
Jonathan Cannon, an assistant professor of psychology at McMaster who was not involved, pointed to two possible confounds. “If a couple of people were consciously aware of the bass and dance more, that can have an amplifying effect in the crowd,” he told Live Science.
He also suspected the floor. “I wouldn’t be surprised if our actual sensations coming from our feet are mediating this,” Cannon said, suggesting a cement floor to limit vibration in a repeat test.
Low end and electronic music
The paper notes that music people want to move to tends to carry more low-frequency sound, and that low pitches produce stronger neural responses for timing than high ones. Electronic music has been built on that since the Roland TR-808 kick, through to the heavy synth bass of darksynth acts such as Carpenter Brut.
We covered another music-psychology finding, the reminiscence bump, earlier this month.
Cannon said he would also like to see the experiment repeated with deaf and hard-of-hearing people, to test whether very low bass moves the body without going through the auditory system at all.
Lead photo: Daniel Nouri / Pexels, Pexels licence