So if I look at a signal like this, so pretend this is my audio equalizer.
And I have low frequency and a high frequency about the same,
then my signal will sound like this.
[SOUND] Now if I take my equalizer, and
I boost the low frequency and keep the high frequency the same,
then what you will hear is that low frequency hum.
So in the first one, there was a little bit of a low frequency hum or
buzzing sound.
Here, what we'll find is that the high frequency is diminished,
and you'll hear a little bit more of that buzzing sound.
[SOUND] Now in this particular case, I've reversed it,
I boosted the high frequencies and got rid of the low frequencies.
So in other words, I should have a clearer signal.
I shouldn't have that buzzing sound.
And instead, you'll hear a high frequency.
That actually sounds almost a little bit more shrill because I'm amplifying it.
[SOUND] So in the rest of this module, we will spend a lot of time looking
at frequency characteristics of signals, in particular, voltage signals.
And we will spend a lot of time looking at frequency response and
Bode plots of circuits.
Now I've introduced the term Bode plots in here,
because that term is often used in real applications.
For example, audio applications and audio speakers,
they're always giving Bode plots to show the frequency characteristics.
And then we will spend a lot of time also looking at filters and designing filters.
All right, thank you.
[MUSIC]