(Inside Science) -- Why is it that some songs get your toes tapping and others leave you cold? Part of the answer may lie in the unique shape of your skull.
In addition to the obvious social and cultural influences on musical preference, there are also a myriad of little physical quirks of the body that affect the way we hear and process sound, particularly music.
A new study presented at the 165th Acoustical Society of America Meeting in Montreal last week added another quirk to the list: skull resonance. It turns out that the unique shape and resonance of a person’s skull could have a subtle impact on the way that she hears different keys of music, and how much she likes it.
It all starts with the cochlea. Located deep within the inner ear, the cochlea is a liquid filled, snail shaped structure that serves as the body’s primary auditory organ. When sound waves enter the ear, they travel through the outer ear canal, or the “external auditory canal,” and strike the eardrum, which causes the eardrum and several tiny bones around it to vibrate. Those vibrations are picked up by tiny hairs within the cochlea that translate those vibrations into electrical impulses. The electrical impulses are then carried to the brain by sensory nerves and voila: you hear a sound with a particular pitch, timbre and resonance that you interpret as pleasant, ghastly or anything in between.
What does this have to do with skull structure?
Location, Location, Location
The cochlea itself is embedded deep within the temporal bone of the skull. This extremely dense bone sets the tone for the way the skull resonates sound and influences how sounds are amplified, diminished and ultimately heard.
Since no two skulls are exactly alike, no two temporal bones or the resonating structures they create are identical, or will resonate the same way. So, researchers at William Paterson University wanted to see exactly how much skull shape and resonance affects what kind of music a person prefers.
The measure of the skull
The study had two parts. First, 16 study participants were presented with a set of simple, original melodies in each of the 12 major keys. After listening to the melodies, the participants were asked how much they enjoyed each melody.
Then, the researchers measured the fundamental frequency of each participant’s skull. This was done by firmly pressing a microphone against the temporal bone while the listener tapped his or her head. Across the panel of participants, skull frequency varied between 35 and 65 hertz. Incidentally, the female participants had slightly smaller skulls and a higher fundamental skull frequency than the male participants.
The researchers found that the resonance of the skull did not seem to have a strong influence on the keys of music the participants preferred, but it did moderately predict the kind of music that the participants disliked.
The cochlea and surrounding structures, it turns out, can reveal more than simply the way we hear.
A 2012 study from Penn State University found that the shape and size of the entire inner ear structure can predict the physical agility of primates. This insight could give researchers a new way to piece together how ancient primates may have moved based on the skull fossils they left behind.