It’s a cold November night in Karlsruhe, Germany. The bulky doors of the Stadthalle are open, revealing all the thick walls and the perfectly designed, acoustically treated venue.
You take your seat and wait for the burgeoning legends of Miles Davis’ second great Quintet to show up. You look around, there’s chatter everywhere, your heart rate is gradually building, and you can sense the excitement raging in the hall. There’s a roaring applause for Tony Williams as he is the first to take the stage and the drums, Ron Carter follows this on the bass, Herbie Hancock on the piano, Wayne Shorter on the saxophone and finally Miles Davis on the trumpet. Breathless silence fills up the room as the crowd eagerly waits for the quintet to take over.
Live in Europe 1967 is a breakthrough moment for every single one of the quintet. Each one of the players would become giants in electric jazz following this gig.
You can hear the raw talent of these legends right away with the frantic opening. You see the youthful new additions of Davis’ quintet bear down into a fierce musical trance, filling the entire room and our ears with strong rhythmic grooves and fresh hypnotic chords.
Sound as we know it is merely vibrations that all life forms process. When individuals enjoy the art of music, be it jazz to afrobeat, is all done by our ears.
But, how do our ears work?
The human auditory system is a complex structure that is divided into three sections. The outer ear consists of the Pinna (the external part of the ear), the Auditory canal and the exterior of the Tympanic Membrane also know as the ear drum. The malleus, incus, and stapes often referred to as the ossicles make up the middle ear. The ossicles are the tiniest bones in the human body. Lastly, we have the inner ear that includes the cochlea and the semicircular canals.
The Outer Ear or the Decoder
The crucial function of the pinna is to decode and imprint all the directional information of the sounds picked up by the ear. The twists and folds of the pinna enhance high frequency (pitched) sounds and also help us to determine the direction of the sound source. As we close our eyes and listen to the music, the pinna tells us that Davis and the trumpet are at the center with 16-year-old drum prodigy Tony Williams, and as he moves, the outer ear unconsciously determines the direction of their location. Sounds coming from the front and sides are slightly enhanced as they are directed into the ear canal while sounds from behind are slightly reduced. Cupping the hand behind the pinna provides small additional amplification to sounds coming from the front because it effectively enlarges the sound collection surface area of the pinna.
The Middle Ear or the Amplifier
As the pinna decodes Shorter’s screeching soprano saxophone to Carter’s bouncy grooves into the language of the Auditory system, the mechanical vibrations swish their way through the ear canal in a matter of nanoseconds and strike a little kick (bass) drum in our ears called the eardrum or the Tympanic Membrane. The eardrum is attached to the ossicles of the inner ear and the stapes is appended to the cochlea. The purpose of these is to convert acoustic energy into mechanical energy. Now, transmitting sound energy from a light medium such as air into a dense medium like water is no easy matter because liquids are practically incompressible. All of the middle ear arrangement behave like a lever system or a hydraulic system.
As the asymmetrical fills and swelling cymbal flurries of Willams’ drums pass through the canal, the codes created by the eardrum form to set the ossicles or lever system in motion. The malleus is connected to the center of the eardrum, and as the eardrum vibrates, it moves the malleus from side to side like a lever causing the hinge-like lever the anvil and the stapes to create waves in the fluid of the cochlea through a special opening called the ‘oval window.’ The pressure at the special window is about 22 times that of the pressure felt at the eardrum.
All the squeaking trumpet solos, the smashes on the ride, the sometimes calm piano solos and the applauds take a toll in the ear. It is, after all a mechanical system. With all the violent movements of pressure and air in the ear, there has to be an equaliser to balance it out. The middle ear is vented to the upper throat behind our nasal cavities by the Eustachian tube. The weird feeling in the ear and throat when you’re 30,000 ft up in the sky is all the workings of the Eustachian tube. It is balancing the different pressures at different altitudes.
Now, the reason we enjoy the sound of a particular instrument, or a distinct solo that exhilarates our emotions and gives us goosebumps is all due to the surreal workings of the inner ear. The cochlea is a snail-like structure that is the size of a pea. It is by far the most complex part of the ear, and its primary job is to take the physical vibrations caused by the sound waves and translate them into electronic information for the brain to recognise a distinct sound.
This snail-shaped organ is filled with a special fluid called endolymph with a high concentration of Potassium (K+) ions. Inside the cochlea, we find the Tectorial Membrane, which moves along with the pressure variations of the cochlear fluid. This membrane is in contact with the cilia on the top of the hair cells. There are two kinds of hair cells. The outer hair cells are the actual receptors. When the membrane moves, so does the hair on the outer cells. This movement is then encoded into electrical signals and goes to the brain through the cochlear nerve. The inner cells have a different role: when the audio signal gets louder, they stick themselves to the membrane in order to limit its movements.
The brain is like a central processor, taking in all the complex patterns of electrical impulses and making sense of it all. We are still a long way from understanding these complex structures. It’s amazing the way these processes take place in such a small area of the body.
Believe it or not hearing loss is increasing. “Nearly 1 in 5 American adolescents have some level of hearing loss.” You can only guess the reason for this. Personal music players, loudspeakers at gigs and festivals. Our ears need to be taken care of. There are simple steps you can take to protect your ears from hearing damage and the first step to healthy hearing is awareness.
Plainly reading about the workings of our ears gives me the shivers. It’s astonishing how the whole system of sound and hearing is made effortless by our ears and brains. It’s a disturbing thought to not be able to listen to Miles Davis again.
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