Additional Info

• ID Code: H5-21
• Purpose: Demonstrate the logarithmic nature of dBs
• Description: The decibel scale measures sound pressure level logarithmically against a base value. As such, a doubling of sound intensity (such as by doubling the number of approximately equivalent sound generators) creates a 3 decibel increase. This scale was developed as a result of Weber's Law: that a noticeable difference in a stimulus is an increase in a constant fraction.

  To demonstrate that doubling the sound intensity creates a change of 3 decibels in the sound intensity level: Divide the class in two, ask one half to make some noise (eg clapping), and note the sound intensity level. Then ask the whole class to make the same noise, raising the sound intensity level by 3 dB. For large groups, a camera may be provided to display the sound level meter.

• Availability: Available
• Loc codes: H5