Decibels

1
Decibels

• Sally is 1 m away from a source of spherical
  sound waves, and records a sound level of 24 dB.
  Wally is 2 m away from the same source, and
  records a sound level of about
• 21 dB.
• 18 dB
• 12 dB.
• 6 dB.

2
Decibel measurement

• In groups, measure the sound level in the room
  when
• Everyone remains quiet and still.
• Each group is in conversation.
• Someone shouts into the meter.
• Music is playing from the speaker system.