Structure of Human Ear
Which is the question, how do the compressions in air become sound in our head? So pretty interesting question and we know that anything to be perceived by our brain will finally has to become electricity. That’s the language which brain understands. Brain understands only electric compressions. So how does the sound gonna converted to that? Let’s find out. so what we know is we all have outer ear called pinna, so we want to have a notice here. The compressions are gonna reach the outer ear called the pinna. Which directs the sound inside exit through the canal and makes it reach the what is called the ear drum, or the tympanic membrane. And this membrane feels those compressions __ it can vibrate along with it. That’s why it is called as drum,it behaves like membrane. Very thin membrane which is stretched out. It begins start compressing, and you know start relaxing based on that . That is not much, what happen s is that that compression is amplified many many times. usually about 20 times, by three bones inside, which is hammer anvil and the stirrup. So these three bones amplifies the sound that you have the little compression and refractions. And that part of the amplification happens what we are call in the middle ear. So middle from the outer ear the pinna, it goes inside these three bones like the inner ear it amplifies the sound. So the outer ear’s purpose bring it in. direct collect the sound and bring it in. the middle ear purpose is to amplify the sound. And after this amplification occurs, this sound is allowed inside the inner ear by what is called the oval window.and this oval window, puts it inside the inner ear which is called the cochlea. Where this sound is converted into electricity. Now you would find out how exactly this done. There is a fluid inside the cochlea which begins to starts vibrating at this level at the same range at which the air vibrates and then the bones vibrate, the fluid picks up the vibration and eventually trying to create a wave inside the fluid and then that is converted into electrical impulses. We will not go to the exact details of how that is done, it is a little too much detail for this purpose here. So what we have? An outer ear, a middle ear and an inner ear. Outer ear the pinna, directs inside,inner ear, hammer anvil and stirrup amplify. Cochlea the inner ear sends it to the brain . Now what happens is that this electrical impulse goes towards to the auditory nerve, to the brain and there it into sound. Now that this are all system put together is how we perceive sound and hear it. There is a little tube called the Eustachian tube which can connect to our hearing to the nasal cavity. We know that ENT doctors exists ear nose and throat which all put together because they are connected inside. So that little tube connects from the inner ear to the nasopharynx is called. It is not very important for our purpose here. For our purpose what we observe here is that compression in the air are converted into electrical impulses.