How Does Hearing Work? The Ear Explained

The human body functions through its senses. The senses allow us to see, hear, feel, taste and smell. Together, these senses work in harmony to keep us functioning at our best, so that we can take part in society. When one of these senses is damaged, we are left with a limitation and can no longer function the way we should. Hearing is one of these senses. It allows people to communicate with one another and to perceive sound. Without us ever realising it, the auditory system is an ingenious piece of engineering that enables us to recognise sounds. So how does hearing actually work? That is exactly what we will explain in this blog.

Sound

Sound consists of sound waves that originate from a sound source. The sound source causes a change in air pressure by means of these sound waves. The sound waves travel through the air and can be picked up by the auditory system. The auditory system carries the sound waves to the brain and converts them into sounds that are familiar to us. When the sound waves are extremely small, they produce a very faint sound that the auditory system can barely, if at all, detect. On average, the human ear can handle around 120 decibels without sustaining damage. Anything above that will also cause pain in the ears.

How does hearing work?

From the outside, all we see is the outer ear. The actual process of hearing takes place inside the ear and in the brain. The sound waves pass through a whole range of components before the brain can finally interpret them as the sounds we know. There are three different sections in the ear that the sound waves travel through: the outer ear, the middle ear and the inner ear. A distinct process takes place in each section, and together they ultimately turn the sound waves into sound.

The outer ear

The outer ear consists of the auricle, the only visible part of the hearing system, the external ear canal and the eardrum. The scientific name for the auricle is the pinna. The auricle acts as a kind of funnel that catches the sound waves. The sound waves then travel down the ear canal and reach the eardrum. The ear canal has a protective function. This is where dirt and dust are trapped, so that they cannot reach the eardrum. The eardrum is a highly sensitive organ, and the ear canal protects it from cold and drying out.

The middle ear

The middle ear consists of the Eustachian tube and a few small bones, namely the hammer, the anvil and the stirrup. These three bones are the smallest bones in the human body. When the sound waves reach the eardrum, the eardrum passes the vibrations of the sound waves on to these bones. Here the vibrations are amplified and converted into mechanical vibrations. These vibrations are then carried on to the inner ear. The Eustachian tube has a function too. This tube is connected to the nasal cavity and the throat cavity, and it ensures that the pressure on the eardrums stays equal on both sides.

The inner ear

The inner ear consists of the cochlea, which in turn is connected to the auditory nerve. The mechanical vibrations that the hammer, the anvil and the stirrup pass on to the inner ear end up in the cochlea. The cochlea is filled with a fluid that is set in motion by the vibrations. Because the inner walls of the cochlea are lined with hair cells, these cells are set in motion as well. At the end of each of these cells sits a nerve ending. The nerve endings pick up the vibrations and pass them on to the auditory nerve. From there, the signal travels to the brain, where the vibrations are converted into a sound that we can understand.

Problems with your hearing

As you can see, sound has to travel quite a long way before we can take it in. As a result, problems can sometimes arise along the way with the transmission of the sound waves or the vibrations. When this happens, you start to experience hearing loss. Hearing loss can already be present at birth due to an abnormality in the auditory system, but in most cases you will only begin to notice hearing loss later in life. This is perfectly logical, because the body’s functions deteriorate with age due to wear and tear, and the same applies to the auditory system.

Overexposure can cause damage too. This type of damage can easily be prevented by wearing hearing protection whenever you are in spaces with loud sounds. Repairing hearing damage, especially damage caused by wear and tear, is usually not possible. There are, however, some excellent aids available, such as a hearing aid, so that you can still hear well despite your hearing damage.

Hearing protection

Of course, the question is not only how does hearing work, but also “how can I protect my hearing as well as possible?” In that case, custom-made earplugs are the ideal solution. Take a look at our range here.