hearing is the perception that results from our ears, transducer and sound sound is a type of vibration that propagates as pressure waves moving through air or water. Now waves have what's known as frequency. This is thesis Eichel's per second of a wave. Here you can see a model of a wave and one cycle would be one complete revolution if you want to think of that of the wave. So if we start at this point on the wave and go all the way until we get to that same point again, that is one full cycle Now, Technically, I should point out that this wave we're looking at here is a different type of wave from a pressure wave. A pressure wave is a longitudinal wave. This is a trance first wave. That's just for the physics people out there for our purposes. It doesn't really matter, because this is actually much easier visual representation than what a pressure wave looks like. So just know that one cycle is essentially one revolution of the wave. If you want to think of it that way and that perception of frequency, which is the number of cycles per second comes in his pitch. That's basically like the notes of music. You hear right, the different types of sound, the different, uh, you know, um, scales of sound that you hear That's just our perception of frequency now, the amplitude of these waves, which you can see here, this amplitude that is what we hear as volume. So the higher the amplitude of the wave, the louder we perceive the sound to be. And our ear is the Oregon that will take in this sound and turn it into something meaningful for our brains. So how does that happened? Well, the year actually has three different parts to it. The outer, middle and inner ear. The outer ear is basically just, you know, the cup that sits on the side of our head that is shaped to best gather sound and filter it into this tube. Now this tube will end at what's called the Tim Panic Membrane. This is the ear drum. It's a thin membrane that separates the outer ear from the inner ear and is going thio essentially represent the first step of sound being, uh carried into the body and turned into a meaningful signals so in the middle ear. We have these bones, and these bones were gonna be responsible for amplifying sounds that come from the environment. These bones air called obstacles, and there's actually three of them, and you can see them. Here we have 12 and three, and these obstacles will move based on sound waves hitting the Tim panic membrane, causing them to move. And basically they're gonna act like a kick pedal on a drum almost and hammer against this structure. The oval window. Now the oval window is a membrane covered opening that leads from the middle ear to the inner ear. So we have these two membrane membrane covered openings, one that you know hits the Ahsoka Lisey's and then the one that the obstacles pound on to essentially transmit sound. Now the obstacle that's actually hitting on the oval window is called Stay peas, and I also want to briefly mention do you station tube. That's actually what connects your middle ear to your nose and throat region, the nasal pharynx and whenever. If you've ever flown on a plane or had your ears plugged up before, that's from your you station tubes. That's from pressure in pressure changes in the station tubes, causing that sensation. So let's actually go ahead and flip the page and move on into the inner ear.