This is the sequence of the process of hearing the human ear

Hearing is one of the main human senses which functions to communicate and alert the body. Through the sense of hearing, you can feel vibrations which are known as sound. This is called the listening process which involves parts of the ear and brain. The explanation below will discuss how the listening process takes place, from receiving sound waves to sending them to the brain.

What are the parts of the ear and what do they do in the listening process?

Before discussing the question of the listening process, you need to know the parts of the ear and their function as the sense of hearing. Here's the explanation:

1. The outer ear

The outer ear consists of the earlobe and ear canal. In the process of hearing, the outer ear is responsible for sending sound to the tympanic membrane (eardrum).

The ear lobe, also known as the pinna, is made of cartilage covered with skin. Pinna collects sound and transmits it to the ear canal.

Meanwhile, the ear canal is about 4 cm long and consists of an outer and an inner part. The exterior is covered with hairy skin which contains glands to form earwax. Hair grows on the outside of the ear canal and acts as a protection and disinfectant.

2. Middle ear

The middle ear is an air-filled chamber that is connected to the back of the nose via a long, thin tube called the Eustachian tube. The middle ear chamber contains three bones which are responsible for transmitting sound from the tympanic membrane to the inner ear. The bone is named malleus, incus, and stapes.

The outer wall of the middle ear is the tympanic membrane, while the inner wall is the cochlea. The upper border of the middle ear forms the bone below the middle lobe of the brain. Meanwhile, the base of the middle ear covers the base of the large vein that drains blood from the head.

3. Inner ear

The inner ear is a space consisting of a bony labyrinth and a membrane labyrinth, one inside the other. The bony labyrinth has a cavity filled with circular canals that are responsible for balancing functions.

The parts of the ears that have been mentioned above are related to one another. These parts come together in the listening process, so you can understand the sound or voice.

What is the listening sequence?

The process of hearing is the process of converting sound vibrations from the outside environment into action potentials. A vibrating object produces sound, then these vibrations exert pressure on the air, which are known as sound waves.

Your ears have the ability to distinguish different sound characteristics, such as pitch and loudness, which refers to the frequency of sound waves and the perception of sound intensity.

Sound frequency measurement is measured in hertz (Hz, cycles per second). The human ear can detect frequencies from 1,000-4,000 hertz. Meanwhile, the baby's ears can hear frequencies in the range between 20-20,000 Hz.

Sound intensity is measured in decibels (dB). The range of human hearing on the decibel scale is from 0-13 dB. All the properties mentioned must undergo a process to enter the central system.

Quoted from the National Institute on Deafness and Other Communication Disorders (NIDCD), here is the sequence of the listening process that you need to know:

1. Sound waves enter the outer ear and travel through a narrow passage called the ear canal, which leads to the eardrum.
2. The eardrum vibrates from incoming sound waves and sends these vibrations to the three small bones in the middle ear.
3. The bones in the middle ear amplify or increase sound vibrations and send them down the cochlea.
4. After the vibrations cause the fluid in the cochlea to vibrate, sound waves travel along the basilar membrane. Hair cells, which are sensory cells that sit on top of the basilar membrane, control sound waves. Hair cells near the wide end of the cochlea then detect high-pitched sounds, whereas those closer to the center detect low-pitched sounds.
5. As the hair cells move, the tiny hair-like components (known as stereocilia) that are perched on top of the hair cells bump into the structures and curves above them. This causes overt stereocilia. Then, the chemicals enter the cells and create an electrical signal.
6. The auditory nerve then carries these signals to the central nervous system (brain) and converts them into sounds that we know and understand.

What are the functions of the brain related to hearing?

When signals from the auditory nerve are carried to the brain, the brain performs its function by supporting your needs. Quoted from the World Health Organization, the following are various brain functions related to hearing:

1. Block unwanted sounds

This ability of the brain makes you able to hear and communicate clearly in a crowded and noisy room. This is also called the cocktail party effect or cocktail party effect.

As you get older, your ability to hear in a crowded room will diminish. This ability will get worse when you have hearing loss or ear disease that affects hearing.

2. Determine the location of the sound source

After listening, your brain can make you determine the source of sound fairly accurately. For example, you know where the sound is coming from, you know where to look for a speaker, you know where to look for airplanes or birds. There are special nerves that handle this in the central nervous system.

3. Determine the sound on and off

Your hearing sense has a warning function for all kinds of signals. There are brain cells that only respond to the initiation of sound, while other brain cells only respond to changes in sound to become inactive.

For example, when someone turns on the air conditioner, you will notice it. Likewise when the tool is turned off.

4. Interaction of sound stimuli with other parts of the brain

Sound stimuli produce interactions with other parts of the brain to provide appropriate responses. That's why, if you hear a fire alarm, your body will automatically react leading to an escape, a pounding heart, and a readiness to move immediately.

Another example is a mother who feels more alert when she hears her baby cry than other people. Certain sounds can provoke anger, pleasure, or something else. In short, the sensations resulting from the process of hearing mix with the body's mechanisms and become a unity.