The HUMAN EAR
The human ear, much like the human eye, is a piece of art as it works so well, but it has a myriad amount of processes, to allow us to hear. An in depth study would suggest that certain disciplines of study should be consulted, to get a true concrete understanding of how the ear works.
When dealing with a complex theory, it is always recommended to break elements down into groups. For example, the human ear has 3 elements to it; the outer ear, the middle ear and the inner ear. Freberg (2010) states that the “outer ear consists of the structures visible outside of the body; the pinna and the auditory canal. The pinna serves to collect and focus sounds, just like a funnel. The pinna also plays an important role in locating the source of sound. Movement of the pinna allows some species to further localise sound […] as when a dog puts it ears back while snarling” (p192). In relation to the future human, it could branch into so many possibilities as the sight sense would be lost, but movement of the pinna can help locate sound. Working further into the ear, there is a point where the outer ear transfers to the middle ear; this is shown in the image above 4 as the tympanic membrane. After passing the eardrum (tympanic membrane), there are three tiny bones, malleus, incus and the stapes. If we think of sound, it is a form of energy, as it is a mechanical vibration. For most energy transfer processes, an ideal system is one where the input = output, and there is no degradation in energy. The three tiny bones in the ear are responsible of maintaining a 1:1 ratio between sound energy and the fluid, which is located in the inner ear. The inner ear is compromised of two fluid based cavities, in the image above they are known as the semicircular canals and the cochlea. A general assumption that can be taken from the shape of the cochlea is that is resembles a snail, as stated by Nevid (2012) “cochlea is the Greek word for “snail” (p94).
When dealing with a complex theory, it is always recommended to break elements down into groups. For example, the human ear has 3 elements to it; the outer ear, the middle ear and the inner ear. Freberg (2010) states that the “outer ear consists of the structures visible outside of the body; the pinna and the auditory canal. The pinna serves to collect and focus sounds, just like a funnel. The pinna also plays an important role in locating the source of sound. Movement of the pinna allows some species to further localise sound […] as when a dog puts it ears back while snarling” (p192). In relation to the future human, it could branch into so many possibilities as the sight sense would be lost, but movement of the pinna can help locate sound. Working further into the ear, there is a point where the outer ear transfers to the middle ear; this is shown in the image above 4 as the tympanic membrane. After passing the eardrum (tympanic membrane), there are three tiny bones, malleus, incus and the stapes. If we think of sound, it is a form of energy, as it is a mechanical vibration. For most energy transfer processes, an ideal system is one where the input = output, and there is no degradation in energy. The three tiny bones in the ear are responsible of maintaining a 1:1 ratio between sound energy and the fluid, which is located in the inner ear. The inner ear is compromised of two fluid based cavities, in the image above they are known as the semicircular canals and the cochlea. A general assumption that can be taken from the shape of the cochlea is that is resembles a snail, as stated by Nevid (2012) “cochlea is the Greek word for “snail” (p94).
The cochlea is filled with a fluid that is composed mainly of water. On the inside of the cochlea, there are many thousands of nerve cells, which appear as microscopic hairs. The hairs hold a prestigious amount of importance as they are designed to send out electrical signals to our brain. As a sound wave, in the form of energy, it enters the ear canal, passes the malleus and goes towards the end of the line, the oval window. The oval window is connected to the cochlea, where the microscopic nerve cells stand upright to assess the incoming wave. Every single nerve cell will have it’s own specific frequency, in which it can react to. When a frequency of the nerve cells, matches the same frequency of a specific part of the sound wave, then it said to “resonate at higher amplitude of vibration” (Siraj, 2012, p8). As the nerve cell will resonate at a higher amplitude of vibration, then it will cause the cell to trigger an electric signal. This electric signal is passed from the cochlea nerve onto the auditory nerve, where it is processed in the brain.
This extremely complicated process is automated extremely quickly, that we don’t seem to notice a time delay, when the object that makes a noise is close to us. What is more spectacular is that blind people are able to use their hearing sense to allow them to figure out their position, within an environment. In some cases, humans are able to deduce colour from a sound.
I have purposefully missed the semicircular canals, as they have no overall impact on hearing. The purpose for the semicircular canals is to maintain balance, when we walk for example, so we don’t topple over. Much like the cochlea, the semicircular canals have microscopic nerve cells, that when fluid is passed along, it detects the change and release an electrical signal, which our brain processes. For example, tilting the head downwards, results in endolymph – fluid, moving along the nerve cells and triggering electrical signals. The brain is capable or registering the electrical signals, which in turn allows the brain to know if we are moving. A sensory mismatch between the eyes and ears can induce motion sickness, which is typically noticed when reading in the car.
To summarise, the human ear has a myriad of functions that work together seamlessly, giving us the talent of hearing so well. There are many elements to the ear, which if an aspect stops working or does not function as it should do, then there is an overall impact; whereby the human is no longer able to hear, or the higher frequencies are lowered. The ear also acts as part of our balancing system, with the help of fluid passing over nerve cells.
Jonathan.
Human Ear - All about healthy and beauty., (2013). Labeled view of the human ear. [online image] Available from: http://winesurprises.com/wp-content/uploads/2013/11/human-ear-czxrpnee.jpg [Accessed 5 March 2014].
Cochlea – John the Math Guy., (2013). Labeled view of the cochlea. [online image] Available from: http://1.bp.blogspot.com/-NuVywkUtOJo/UaPc8goTn-I/AAAAAAAACaI/oXJjkO9s_os/s1600/Snail+and+cochlea.png [Accessed 3 April 2014].
Freberg, L., (2010). Discovering biological psychology. Belmont, Calif.: Wadsworth, Cengage Learning.
Nevid, J. S., (2012). Essentials of psychology. Belmont, CA: Wadsworth, Cengage Learning.
Siraj, Z., (2012). Time-Varying Compression Amplification with Spectral Sharpening. University of Maryland, MD: Proquest, Umi Dissertation Publishing
This extremely complicated process is automated extremely quickly, that we don’t seem to notice a time delay, when the object that makes a noise is close to us. What is more spectacular is that blind people are able to use their hearing sense to allow them to figure out their position, within an environment. In some cases, humans are able to deduce colour from a sound.
I have purposefully missed the semicircular canals, as they have no overall impact on hearing. The purpose for the semicircular canals is to maintain balance, when we walk for example, so we don’t topple over. Much like the cochlea, the semicircular canals have microscopic nerve cells, that when fluid is passed along, it detects the change and release an electrical signal, which our brain processes. For example, tilting the head downwards, results in endolymph – fluid, moving along the nerve cells and triggering electrical signals. The brain is capable or registering the electrical signals, which in turn allows the brain to know if we are moving. A sensory mismatch between the eyes and ears can induce motion sickness, which is typically noticed when reading in the car.
To summarise, the human ear has a myriad of functions that work together seamlessly, giving us the talent of hearing so well. There are many elements to the ear, which if an aspect stops working or does not function as it should do, then there is an overall impact; whereby the human is no longer able to hear, or the higher frequencies are lowered. The ear also acts as part of our balancing system, with the help of fluid passing over nerve cells.
Jonathan.
Human Ear - All about healthy and beauty., (2013). Labeled view of the human ear. [online image] Available from: http://winesurprises.com/wp-content/uploads/2013/11/human-ear-czxrpnee.jpg [Accessed 5 March 2014].
Cochlea – John the Math Guy., (2013). Labeled view of the cochlea. [online image] Available from: http://1.bp.blogspot.com/-NuVywkUtOJo/UaPc8goTn-I/AAAAAAAACaI/oXJjkO9s_os/s1600/Snail+and+cochlea.png [Accessed 3 April 2014].
Freberg, L., (2010). Discovering biological psychology. Belmont, Calif.: Wadsworth, Cengage Learning.
Nevid, J. S., (2012). Essentials of psychology. Belmont, CA: Wadsworth, Cengage Learning.
Siraj, Z., (2012). Time-Varying Compression Amplification with Spectral Sharpening. University of Maryland, MD: Proquest, Umi Dissertation Publishing