Bass Gets Us Grooving, Even if We Can’t Actually Hear It
Even DJs who barely register above a “Paris Hilton” on the mixing aptitude scale know that flooding the dancefloor with bass can get a crowd moving. A new study suggests that at least some of this groove-inducing effect is due to sounds that the human ear can’t even perceive.
The study, led by researchers at McMaster University, is published in the journal Current Biology.
Bringing beats to the lab
First author Dr. Daniel Cameron works at McMaster’s LIVELab, which conducts experiments using live music in a one-of-a-kind venue–research lab hybrid space. Cameron and colleagues recruited 133 people attending a gig from the electronic duo Orphx hosted in LIVELab. The space is fitted with a dynamic sound system that can mimic different types of concert and 3D motion capture equipment.
Cameron’s team used this equipment to monitor the gig-goers dance moves. Over 55 minutes of the concert, the scientists tweaked the speakers, which were capable of outputting incredibly low bass frequencies (at between 8 and 37 Hertz). The team switched the ultra-low frequencies off and on in 2.5-minute increments. During the periods where the ultra-low bass played, the team noted that people danced 11.8% more.
These frequencies are on the edge of what human hearing can perceive, so the team conducted surveys before and after the gig, which suggested that the switch to lower frequencies was undetectable to the attendees.
Why do humans like to move to music?
“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 Cameron. “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?”
The authors suggest the vibrations produced by the sound system interact with the body through touch. They also note that connections between the inner ear and brain also interact closely with the motor system. This anatomy could detect low frequencies and can affect how listeners perceive groove and rhythm, while tying into the brain’s reward system at the same time.
“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.”
“Very low frequencies may also affect vestibular sensitivity, adding to people’s experience of movement. Nailing down the brain mechanisms involved will require looking the effects of low frequencies on the vestibular, tactile and auditory pathways,” Cameron concludes.
Reference: Cameron DJ, Dotov D, Flaten E, Bosnyak D, Hove MJ, Trainor LJ. Undetectable very-low frequency sound increases dancing at a live concert. Current Biology. 2022;32(21):R1222-R1223. doi:10.1016/j.cub.2022.09.035
This article is a rework of a press release issued by McMaster University. Material has been edited for length and content.