Measuring sound

Some sounds are soft and others are loud. The loudness of a sound is called the ______.

• decibel

• volume

• speaker

• microphone

Sound levels, or volume, are measured in special units called ______________.

• centimeters (cm)

• degree Celcius (°C)

• decibels (dB)

• noise (Ns)

What is the sound level of a jet on take-off?

• 135dB

• 140dB

• 150dB

• 120dB

What is the level at which sound damages your ears?

• 135dB

• 140dB and more

• less that 140dB

• 120dB

Most health authorities suggest ear protection for sounds above 85 decibels. Do you think you should wear ear protection when using a lawnmower?

• Yes

• No

We use a ________ level meter to measure the volume of sounds in decibels

Explain how you think a sound level meter works.

• The microphone records the light and the meter measures it brightness. The sound level is displayed digitally on a small screen

• The microphone records the sound and the meter measures it volume. The sound level is displayed digitally on a small screen

• The microphone records the loud sound only and the meter measures it volume. The sound level is displayed digitally on a small screen

• The microphone records the low sound only and the meter measures it volume. The sound level is displayed digitally on a small screen

What sounds might have given the reading of 125.1 dB.

• whispering

• rain falling

• loud firework

• busy city traffic

What sounds might have given the reading of 53.8 dB.

• someone talking quietly

• rain falling

• loud firework

• busy city traffic

The decibel scale is used to give the sound levels of different sounds or noises

• True

• False