How hearing works

We live in a constantly evolving, dynamic world where hearing is one of the key factors for cognitive development, social interaction and an active lifestyle. Listening to the birds singing in the morning, jumping at the sound of a bicycle bell or enjoying a secret whispered into your ear, these are moments in life that we want nobody to miss out on.

How does sound reach the brain?

The ear is capable of transforming sound into auditory sensations. It captures sound waves in the environment, converts them into electrical signals and sends them to the brain, where they are decoded and recognized. It is the sense that allows us to be in contact with the world around us.

The outer ear

The middle ear

The inner ear

The brain

The outer ear

The beginning of the journey

The journey of sound until it is interpreted in the brain starts with the entry in the ear from the auricle. The auricle, the external part of the ear, helps determine the direction of the sound and sends it to the ear channel which, in turn, channels it into the middle ear.

The middle ear

The encounter with the eardrum

When sound reaches the middle ear, it meets the eardrum, a very thin membrane that starts to vibrate transmitting the sound to the three smallest bones in the human body: the hammer, anvil, and stirrup. These bones amplify the sound and transmit it to the inner ear.

The inner ear

The true hearing organ

Once sound, a vibration that first propagated in the air, reaches the inner ear, it is diffused through the fluid contained in the cochlea. In this way it reaches over 20,000 sensory cells.

The cochlea can be considered the true hearing organ as this is where thousands of hair cells transform the mechanical vibrations of sound into electrical impulses that reach the brain to be processed.

The brain

The destination

It is only here, in the brain, that sounds already transformed into electrical impulses are translated into various perceptions and sensations and become sounds, words, concepts, and emotions.

Hearing loss

In most cases, hearing loss is not drastic but occurs gradually without us perceiving exactly how much it has changed. However, it can also happen suddenly after exposure to loud noises, infections or pharmacological therapies.

High pitch sounds, such as birds chirping, bells or the sound of the rain, are the first to be lost, then comprehension of speech and dialogues in noisy environments become harder. As time goes by, the cells that perceive low pitch sounds also begin to lose their effectiveness, making it more difficult to communicate even in silence or at close distances.

Focus: the hair cells

The sensory cells of the auditory system have different functions: some are specialized in sounds with higher frequencies, and others in sounds with lower frequencies. The hair cells dedicated to high frequencies are the first to meet the sound waves and this is why they undergo greater stress and deteriorate more quickly than the others. Unfortunately, unlike skin or liver cells, auditory hair cells cannot regenerate.

The sound map

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World Health Organization

currently around 1.5 billion people across the world have some level of hearing loss

Of these, it is estimated that at least 430 million would require rehabilitation, thus affecting people's quality of life. Due to the increase in life expectancy of the global population and the increase in noise exposure, this number is likely to reach 700 million by 2050.

Additionally, over one billion young people aged between 12 and 35 years are at risk due to excessive exposure to sound. This is why we are increasingly active in promoting greater awareness of the importance of hearing well-being and responsible listening.

WHO: hearing loss classification

Mild – trouble hearing conversations from one room to another, as well as in noisy environments such as busy restaurants (26–40 dB)
Moderate – trouble understanding what is being said even if the person speaking is close by. Words and sentences have to be repeated, said more slowly and concepts have to be rephrased, even listening to the radio or TV becomes difficult (41–60 dB)
Severe – most speech is not understood, and it is increasingly difficult to follow conversations. Only very loud sounds, such as ambulance sirens and noisy traffic, are perceived (61–80 dB)
Profound – almost no more sounds can be heard (>81 dB)

Innovation for well-being

We are dedicated to researching into new technologies and innovations that allow people to continue living active lifestyles and enjoying all life's moments. Only through the extensive knowledge and continuing professional development of our highly qualified hearing care specialists is it possible to develop new solutions that meet these different needs.

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How hearing works

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