Why your parents tell you to turn the volume down when you are listening to loud music?
Because listening to loud music can hurt your ears.
What unit do we use to measure the movement of sound?
We use hertz (Hz) to measure the movement of sound.
What is the range of sounds that human can hear?
Human can hear sounds from 20 to 20,000 Hz.
What is the range of sounds that dolphins can hear?
Human can hear sounds from 75 to 200,000 Hz.
What do we use to measure the volume of sound?
We use decibels (dB).
How loud is the sound of a jet engine?
140 dB
How loud is the sound of a rock concert?
115 dB
What volume is the best for human’s ears?
50 dB
What do you wonder?
...
It’s too loud! Can you ___________, please?
Can you turn the volume down, please?
It’s too small. I can’t hear it.Can you ___________, please?
Can you turn the volume up, please?
