The Chemistry of Sound


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This is the chemistry of hearing. This includes the outside of your ear, the “pinna”, the eardrum, or the “tympanic membrane”, and the inner ear bones or the “Hammer, Anvil, and Stirrup”. I chose this topic to study because the transition of a mechanical wave of molecules turning into electrical nerve pulses is fascinating. Studying hearing includes sound waves, pressure sensitive pieces of skin, and the conversion of mechanical into electrical. My life specifically is affected by this because without being able to hear I would not be able to play guitar. Hearing is important for everyone since it is required for communication, balance, and location.

Composition of ...

  • Pinna (the ear that is seen by everybody): cartilage and water H2O and  C28H48N2O32S4
  • Tympanic Membrane (eardrum):keratin sulphate C28H48N2O32S4
  • Inner Ear bones: Ca10(PO4)6(OH)2

Main Chemicals, Compounds, Components

Tympanic Membrane: It is made up of two epidermal layers called the pars flaccida and the pars tensa. This is the keratin sulphate (C28H48N2O32S4) which is almost the same as skin. The two layers of skin are what vibrate when sound molecules hit them. This causes the ossicles, or the tiny inner ear bones to move. The sound reaches the eardrum because it is captured by the Pinna, or the outer ear. After the sound is captured by the pinna it is sent down the ear canal. The ear wax in the ear canal actually dampens the sound so it doesn’t burst the eardrum. At the end of the ear canal is the tympanic membrane. Once the molecules hit the tympanic membrane it starts the whole process. The eardrum is the only place where we can find the same material that makes up the pars flaccida and the pars tensa.

Inner ear bones: The bones in your ear are extremely small and are made almost exactly like the other bones in your body (Ca10(PO4)6(OH)2 )The first bone is the Malleus. The malleus is the bone that is connected to the T.M. (tympanic membrane). This bone is referred to as the ‘Hammer’. The second bone is the  incus or the ‘Anvil’. The final of the three bones is called the stapes, or the ‘stirrup’. Sound causes the T.M. to vibrate which causes these bones to vibrate. The vibration of the stirrup bone in the opening of the cochlea transfers sound energy to the fluids and tissues of the cochlea. It is all possible because of the unique chemical properties of each component. The inner ear bones are completely unique in bone structure as well as the composition of them.

Chemistry's Role

The Tympanic Membrane and the three inner ear bones are not made by man. They are created around the first 6 weeks of the pregnancy. After that they eventually become noticeable and by week 16 the inner ear is connected to the neurons in the brain. The cells will gradually reproduce and some will become skin cells, others brain cells, others will become bones. The ear is created when the baby is created and grown in the womb. Without chemistry there would be no cell that bonds together to create the beginning of the cartilage. The inner ear bones have to be connected to the T.M. in order for the ability to hear. Without chemistry the middle bone, the incus, wouldn’t be there. Any of the cellular make up requires the use of chemistry. The ability to hear was created by the cells coming together as a baby in the womb to start the process. The cartilage in our outer ear is a combination of water and C28H48N2O32S4 or cartilage. The only reason that we can hear is because of chemistry.

Background Research

  • Sound is the vibration of the air molecules through a medium, usually air

  • It has a start when something starts the vibration. A medium to go through air, water, or gas. And our ears capture the sound and turns it into an electrical nerve impulse.

  • Sound is not made out of anything except the substance it is traveling through.

  • The chemicals involved in air are 21%Oxygen 78%Nitrogen and about 1% of Argon

  • Chemical reactions needed is the changing of the vibrations in the inner ear fluid to electrical nerve pulses

  • As sound reaches the ear via air molecules being pushed away from the starting point. The outer ear channels the sound waves, or molecules, into the auditory canal. Then the eardrum senses the pressure change in the middle ear and is transferred from air to bone. The sound  then travels through a maze of inner ear bones. The inner ear gives way to bones that cause a liquid to go into motion. That motion is what causes the signal to be picked up and carried off to our brain.


sense of sound and the music of molecules
sound of the molecules


science of sound
high and low pressure

sound: is a vibration that is a mechanical wave or pressure displacement through a medium of air or water.

sonochemistry, the ultrasound with bubbles and caviation

how sound works
the moving of molecules

sound through air
the conversion from ear to brain
Robert Boyle- vacuum of sound
science of sound waves

What air is made of 21%Oxygen 78%Nitrogen 1%Argon

how the air molecules work

The inner ear converted to brain signals

Outer, Middle, and Inner ear

The chemistry involved in the ear
What the parts are in the ear

The chemical composition of cartilage

Chemical formula for cartilage

Chemical formula for bone.

Hearing during pregnancy

About the Author
Benjamin Arbizzani is a student at Billings Senior High. He is actively involved his youth group and has a passion for engineering. Ben loves to hang out with his friends and consume vast amounts of coffee. He wants to go into an engineering program at MSU in the fall for mechanical engineering.  He loves his classes that involve science, math, and engineering. Ben enjoys his chemistry class the most. He loves being able to apply the chemistry he learns in school to life outside of class.