The way we experience a medium impacts how we respond to it. As a musician, I like to talk about how we perceive sound as an example of this. Sound can be both auditory and physical — sound waves apply pressure as well as be heard by us. Humans have evolved to be pretty sensitive to certain sounds; some can trigger physiological or emotional responses. As humans, we have evolved to feel alert at a baby’s cry or at sounds of threat. Earth produces its own electromagnetic frequency that hums constantly in our atmosphere, it being invisible but always present. Even before we are born, sound begins sending signals to our brains, making us respond. The auditory medium stands out because of this.
The long evolutionary history of sound makes it interesting. People don’t just listen and respond. This is a phenomenon that has existed since prehistoric life first formed on this planet. About 320 million years ago, early animals learned to puff up their body parts as a visual warning to communicate. Then around 300 to 250 million years ago, ancient crustaceans and insects communicated by clicking and buzzing. Crickets and other insects began to chirp, which we still hear on summer nights or dewy early mornings. Every living thing is constantly listening and responding. That is why sound is such a powerful medium.
I recently enjoyed a lecture in my Sound Recording 3 class about ears. Not the amazing electronic duo ear. I mean the ones on our heads. Our ears are doing a ton of work all the time, no pun intended. The physics behind how we hear is truly captivating. Inside our ears are a bunch of different tiny parts that we often don’t think about. Many people know that the cochlea exists inside our ears from learning about cochlear implants or knowledge of anatomy. What a lot of people don’t know of is the basilar membrane, a fibrous, flexible structure that separates fluid pockets in the cochlea. Different frequencies produce vibrations along the membrane, where they get broken up and sent to our brains. There are many different types of shapes of sound waves, but all naturally occurring sounds are complex sounds. This means there are overtones and additional frequencies that exist at all times. The basilar membrane takes those complex sound waves and sorts them (interpreting each frequency), simplifies them, and then feeds those signals to our brains, where we then reassemble and distinguish those sounds into their complex forms and process them.
The way our brains recognize patterns in music is also interesting. Active listening, for example, requires attention and engages processes involved in auditory perception, memory, and prediction. Because music has recurring patterns, our brains constantly make predictions about what comes next. When we listen actively, our brains use patterns we have already learned to anticipate what happens next.
Our ears are doing more than just hearing. They keep us balanced. Sound is always around us, and our brains are always working to perceive it. It is now impossible for me to listen to any sound and not acknowledge all of the inner workings happening inside my head to make my perception possible. It is an amazing thing to think about, and I advise anyone interested to look further into these topics.
