5.3_Loudness and decibel scale

Sound that we do not want to hear are called

• noise

• music

One of the worlds loudest musical instruments is the

• nadaswaram

• trombone

• piano

• vuvuzela

The loudness of the loudest possible continuous sound is

• 50 dB

• 120 dB

• 194 dB

• 250 dB

Loud sound can damage your hearing.

The risk depends on :

• number of decibels

• length of time you are exposed to the sound

• both are true

• both are false

To reducing the risk from noise

• Purring something between the source of the sound and your ear, such as ear defenders.

• Increasing the distance

  Moving away from the source of the sound

• Reducing the time that you spend near the source of the sound.

• All are correct

Sound levels are measured in ................

• decibels

• kilometers

• voltage

• grams

How much louder is a 40 dB sound compared with a 30 dB sound

• one time

• ten times

• hundred times

• thousand times

Choose two jobs for which people should wear ear defenders

• roadworker

• aeroplane engineer.

• office manager

• programmer