How do we hear the sounds around us? Have you ever wondered how music can make you feel a certain way, or how a sudden sound can cause you to jump in fright? Our ability to hear and process sounds in a meaningful way involves an incredible number of processes working together, that transform physical sound waves into electrical signals carried through the brain. In this blog, we'll dive into the intricate processes that make up our auditory system. From the moment sound waves enter our ears to the complex neural pathways in our brains, we'll unravel the mysteries of this sensory experience.
Ever wondered how we hear the sounds around us? Explore the intriguing process explained!
The ear and the auditory pathways throughout our brain together form our auditory system. Our healthy auditory systems are capable of detecting low-pitched bass sounds down to 20 Hz to high-pitched squeaky sounds up to 20,000 Hz. It can filter out background noise and tell us where a sound is coming from. When a sound arrives at the ear, our hearing system works in an instant to process the sound and provide meaning for us to understand or respond to the sound.
Understanding how the ears work
To understand how we hear sounds, let's start by looking at how our ears work. The ear is made up of three parts: the outer, middle and inner ear. Each part plays a crucial role in collecting and processing the sound.
What is the Function of the Outer Ear?
The outer ear plays a crucial role in capturing and transmitting sounds into our ears. Sound waves in our environment first arrive at the pinna of the outer ear. The pinna is the visible portion of the ear at the side of our head. It collects sound arriving at our ears and funnels the sound into the ear canal. As sound is collected and travels through the ear canal, it is amplified and processed for localization cues, telling us where the sound came from. At the end of the ear canal, the sound reaches the eardrum (tympanic membrane), which forms part of both outer and middle ears.
How does the Middle Ear work?
The middle ear starts at the inner lining of the eardrum and houses the three middle ear bones (ossicles) in an air-filled cavity. When sound arrives at the eardrum, it causes a vibration of the eardrum that sets off a reaction through the malleus, incus and stapes. These three tiny ossicles further amplify the sound before the sound reaches the inner ear.
The Eustachian Tube and Middle Ear
The Eustachian tube connects the middle ear to the back of the nose and serves a main function of ventilating and draining the middle ear. This allows the pressure on either side of the eardrum to be equal, allowing the eardrum to vibrate normally and transmit sounds through the ear.
What is the Function of the Inner Ear ?
Sound waves reach the inner ear via movement of the stapes attached to the oval window of the cochlea, the hearing organ. The cochlea is filled with fluid that moves in response to the vibrations from the oval window. This movement sets off reactions in the tiny hair cells sitting in the fluid which result in electrical impulses travelling up the auditory neurons making up the auditory nerve and through the different hearing centres of the brain.
Aside from the hearing organ, the inner ear also comprises the vestibular organ responsible for our balance.
How does the Auditory Nerve and the Brain contribute to our hearing?
The auditory nerve and hearing centres in the brain such as the brainstem and auditory cortex help process and decode different aspects of the sound signal. They help to process the sounds coming from both ears, distinguishing important sounds amongst background sounds. When sound information is degraded or incomplete, the further processing to ‘fill in the gaps’ is required for us to understand the meaning of the sound.
The brain centres involved in processing emotions and memory are engaged to further understand the deeper meaning of the sound so that we can respond appropriately. To run away from a sound that we know to be associated with danger, to feel sadness or anger when we hear bad news, or to refrain from dancing in public when we hear the first few notes of our favourite song. The ability to understand extends far beyond whether we can hear a sound or not!
In exploring the topic "How do we hear the sounds around us pass through our ears?" we've taken a closer look at the fascinating processes that make it all possible. From the outer ear catching sounds to the inner ear turning vibrations into signals for our brain, it's like a magical journey through our auditory system.
Our ears and brain work together to capture a wide range of sounds, filter out background noise, and help us understand where a sound is coming from. Starting with the outer ear collecting sounds, moving through the middle ear amplifying them, and ending in the inner ear translating vibrations into signals for the brain, it's a seamless process that happens in an instant.
The auditory nerve and different parts of the brain team up to process and make sense of what we hear. They not only help us understand the literal meaning of sounds but also add emotions and memories to the mix.
So, the next time you're moved by music or startled by a sudden sound, know that it's all thanks to this incredible symphony of processes. Our ability to hear is more than just a physical act—it's a blend of science and sensation, creating a meaningful soundtrack to our lives.
Visit our audiology clinic at Family Hearing Centre in Auckland for a personalised and thorough hearing assessment. Our team of dedicated professionals are here to guide you through the intricacies of your auditory health. Discover the magic of hearing and ensure your ears are in tune for all of life's beautiful sounds.
Book your appointment at our hearing and ear clinic and embark on a journey to better hearing at Family Hearing Centre.