A new study by researchers from McMaster University found that the human body responds to low frequency sounds, even below the level of human hearing, in a way that makes the body want to move.
The study, published in Current Biology, described an interesting experiment in which the researchers played music at low frequencies that were below the threshold of human hearing. They would turn the music on and off at varying intervals. Even though the participants couldn’t hear the music, they responded with movement every time the music was active. Not everyone reacted to the inaudible sounds, but a measurable percentage were clearly influenced by the music they couldn’t hear.
We already know that music connects with our brains on a deeply emotional level. Anyone who has ever taken public transit can attest to the number of people who are intimately connected to music on a daily basis.
Lower frequency sounds generally act as guides to rhythm and timing of music. Higher frequency sounds control the emotional aspects that we react to, often associated with memories and experiences from the past.
What’s interesting is that there appears to be a part of music that bypasses the aural channel and integrates into our neurology through inaudible frequencies alone.
“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?” asked Daniel Cameron, a neuroscientist from McMaster University, an avid drummer and one of the authors of the study.
In the study, a follow-up questionnaire found that the participants were aware of the music playing, even though they couldn’t hear it. Cameron explained that, “The study had high ecological validity, as this was a real musical and dance experience for people at a real live show.”
At this time, there’s no understanding of how the experiment impacted the listeners. In other words, we don’t know the physiological elements that caused them to respond to the sounds they heard. However it works, Cameron and his team are intrigued by the implicit actions of bass affecting our behavior on a subcortical level.
“Very low frequencies may also affect vestibular sensitivity, adding to people’s experience of movement,” said Cameron. “Nailing down the brain mechanisms involved will require looking at the effects of low frequencies on the vestibular, tactile, and auditory pathways.”
