Music and Neuroscience

How does the ear work?

According to The National Institute of Deafness and other Communication Disorders, sound waves enter through the outer ear which is the part we can see and it's also known as the pinna. Then they go through the ear canal all the way to the eardrum, which then starts to vibrate. These vibrations are sent to three small bones called Malleus, Incus and Stapes. These are considered the middle ear. The vibrations are then sent to the inner ear. They then reach the cochlea, a fluid filled snail shaped structure with an elastic partition down the middle, called the basilar membrane. Once the vibrations are inside the cochlea, it causes a ripple in the fluid which creates a traveling wave along the basilar membrane, which is covered in a type of tiny hair cells, and they ride the wave. The hair cells near the opening of the cochlea hear high frequencies, the ones close to the center hear low frequencies. The hair cells move up and down creating microscopic hair-like projections, known as stereocilia, that perch on top of the hair cells and bump against an overlying structure, causing them to bend. This bending causes channels at the tip of the stereocilia to open up. When this happens, chemicals rush into the cells to create an electrical signal. The auditory nerve carries this signal to the brain, which turns it into a sound we can recognize and understand.

How does each part of the brain react to music?

According to the University of Florida, pretty much every part of the brain is affected or used when we listen to music, their functions and reactions are all very different:

Frontal lobe: is used in thinking, decision making and planning.

• When we listen to music, we're able to enhance those functions.

Temporal lobe: helps us process what we hear.

• It's able to interpret both the music and language used in the lyrics.

Broca's area: enables us to produce speech.

• It's used to express music(e.g. singing).

Wernicke's area: Comprehends written and spoken language.

• It's used to analyse music.

Occipital lobe: processes visual information.

• Can be used to process and visualise music(e.g. music scores).

Cerebellum: coordinates movement and stores physical memory.

• It's used to help remember movement to express music(e.g. playing an instrument).

Nucleus accumbens: seeks reward and pleasure, it plays a big role in addictions and releases dopamine.

• When we listen to music it increases dopamine release(therefore music can be addicting).

Amygdala: processes and triggers emotions.

• When we listen to music we often have emotional responses to it.

Hippocampus: produces and retrieves memory, regulates emotional responses and helps us navigate. It's considered the central processing unit of the brain.

• When we listen to music neurogenesis increases in the hippocampus, this allows production of new neurons which improves our memory. It also interacts with the amygdala to process and retrieve emotional memories.

Hypothalamus: Maintains the body's status quo. It links the endocrine and nervous systems. It produces and releases the hormones that regulate thirst, sleep, mood, heart rate, body temperature, metabolism and growth.

• When we listen to music the value of some of these hormones change

Corpus Callosum: enables communication between the left and right sides of the brain. This allows coordination of body movements and more complex thoughts that require both logic(left side) and intuition(right side).

• It's often used for playing instruments(e.g. Translating music notes to the music you play)

Putamen: processes rhythm and regulates body movement and coordination

• When we listen to music it increases our response to rhythm.