Hey.
Looks like you are searching for a treasure hidden in a sunken ship.
Why don't you use a sonar?
It will emit ultrasounds and help you locate the ship.
You know what.
I have a better idea.
No.
A music system will make ordinary sound.
So, it is of no use.
Don't fool me.
I know that the music system is the right choice.
See.
You are not able to find the ship.
Now will you use a sonar?
Look.
You easily found the ship.
Do you know how a sonar could locate the sunken ship?
It was because of ultrasound.
Ultrasounds are sounds having very high frequencies which start from 20,000 Hertz.
So, is ultrasound used in sonar because of its high frequency?
You are absolutely correct.
Due to its high frequency, an ultrasound can penetrate to a greater depth.
Thus helping us to locate the depth of the sea, sunken ships, etc.
But, I am not able to hear the ultrasound?
It is because human beings can hear sound frequencies from 20 Hertz to 20,000 Hertz.
As ultrasounds have frequencies higher than 20,000 Hertz, we cannot hear them.