either in space or time. And we have different different symbols

to represent the two, but they're they're analogous to each other, okay.

And so, I can do the same thing with with in the time domain I can represent that

same [UNKNOWN] response characteristic, and this just happens to be one period of

oscillation. So, the amount of time it takes here is

one period of oscillation for this particular wave, all right, to propagate.

Now, when we move to sound wave propagation in air.

we can easily relate to wavelength to the frequency.

And that's done through the speed of sound.

And so, in air in particular. And so, before we get into those details

we need to define a few basics. So, we need to define our, you know,

we'll do it at room temperature that's what we're going to be working at,

especially around the concept of speaker design and typical acoustics in the

musical range. but speed of sound in air is roughly 340

meters per second 343 at 20 degrees c. And then the density of air, which is

important as well for some of the calculations we make, is 1.21 kilograms

per meter cubed. And you notice that I'm working in the

metric units here. Alright.

So, the relationship between wavelength and frequency of sound and air is fairly

simple. And it's expressed here, lambda, the

wavelength of the frequency. the wavelength, special wavelength, is

related to the speed of sound in air. Remember that's, that's in meters per

second. And frequency is m1 over seconds, so, you

know, if you look at the units on this, you have meters per second divided by 1

over second, which gives you units of meters, all right?

And that makes sense, because the wavelength is going to be represented in

a measure of meters. so let's talk a little bit about the

relationship between, our audible range, and then of course the the wavelength of

sound in the audible range. So, humans actually hear sound in

wavelengths that range from about 20 hertz at the low frequency to 20

kilohertz at high frequency. And you know the older you get actually

you get you, your, your response at higher frequencies decreases.

we know that but, but It's but at birth basically you have a, a range of about 20

hertz to about 20 kilohertz, and it varies from person to person depending on

auditory capabilities. So, you've just computed the wavelength

of sound at 20 hertz. what is the wave length of sound at 20

kilohertz? It's pretty simple all you have to do is

divide that by a thousand. and if you do that you get a wave length

of 1.7 centimeters. So, if our audible range is from 20 hertz

to 20 kilohertz, that's the frequency range over which we hear it corresponds

to wavelengths that range from 17 meters to 1.7 centimeters.

So, the wavelength the sound at 20 hertz is 17 meters long.

Now that's, that's, that's a large wavelength.

If you think about the, look around your surroundings at your room most of you

probably aren't in a room at this point in time that has a dimension of 17 meters

in any given dimension. So, this a really long wavelength,

particularly compared to the size of your head and the distance between your ears.

at high frequency, though at 20 kilohertz for example, wavelengths only 1.7

centimeters long, so it's very short. So, this is important because it's, it's

important in particular in relation to how we actually localize sound.