What is it about bass-heavy music that gets people to dance? That’s the essential question at the heart of the study, titled Undetectable very-low-frequency sound increases dancing at a live concert. The results of the study by researchers at McMaster University were published in the journal Current Biology on November 7.
The study notes that the low-frequency sounds played by bass instruments are a prominent element in dance music. But, is that what actually gets people on their feet?
“I’m trained as a drummer, and most of my research career has been focused on the rhythmic aspects of music and how they make us move,” says Daniel Cameron, lead author and a neuroscientist at McMaster University in Science Daily. “Music is a biological curiosity — it doesn’t reproduce us, it doesn’t feed us, and it doesn’t shelter us, so why do humans like it and why do they like to move to it?”
Those low-frequency notes
Low-frequency notes are processed differently than high frequency notes. The authors cite several other studies that have looked at those processes.
- Low pitches are more strongly tied to the timing of movements;
- They exhibit stronger neural responses as compared to high pitches;
- It suggests the idea that low-frequency pitches have a stronger sensory-motor connection.
Low-frequency sounds are processed not only through the auditory (hearing) channels. We also experience them as vibrations, and through the vestibular (or inner ear) system.
The researchers posit that it’s those non-auditory pathways, which react much more strongly for lower than higher frequencies, which lead to what they call “groove (the pleasurable urge to move to music)”. It also heightens the perception of rhythm.
What was not previously known, however, was whether these differences in perception actually lead to actions in the real world, or if the frequencies below the level of human perception can also affect our behaviour.
The experiment involved using very low-frequency (VLF) speakers during a live concert of electronic music. The VLF speakers were turned on and off at intervals during the concert, and the audience’s reactions were recorded with motion capture.
“The musicians were enthusiastic to participate because of their interest in this idea that bass can change how the music is experienced in a way that impacts movement,” says Cameron. “The study had high ecological validity, as this was a real musical and dance experience for people at a real live show.”
The researchers used McMaster’s LIVELab, a performance venue that doubles as a testing centre dedicated to exploring performing arts via science.
What they found
Because the VLFs played at or below the level of the human auditory threshold, it was presumed they were undetectable by the crowd, and that any behaviours that resulted were the result of the unconscious perception of the low-frequency sounds.
A second experiment confirmed the hypothesis that the VLFs were not detectable, meaning they could be used without the audience being aware of it.
- Consenting audience members were outfitted with motion-capture marker headbands;
- They also filled out questionnaires before and after the concert;
- The VLF speakers played between 8–37 Hz, and were turned on and off every 2.5 minutes over a 55-minute period;
- They calculated head movement speeds, and compared them to a baseline;
- The level of movements increased when the VLFs played on average by 11.8%.
The authors write that one theory favours the inner ear connection for VLFs. The paper also takes into account that cultural as well as individual experiences may come into play, but the fact they are undetectable suggests that the reaction is a common and fundamental element of how we as human beings connect sound and dance.
It confirms what nightclubbers have always known — that it’s the beat that gets you on the dance floor.