Transcript: Estimate sound levels multiple choice
Image of speaker with curved lines indicating sound radiating from the front. The lines are small and thick close to the front of the speaker, and become long and thin as the move away.
Question:
According to the sound technician, the sound level of the stage speakers will be 100 decibels from 1 metre away, which is the standard volume for an outdoor concert. Using the inverse square law rule for estimating sound levels, which of the following ranges represents the volume of the music at 75 metres away?
a. 45-55 decibels;
b. 55-65 decibels;
c. 65-75 decibels;
d. 75-85 decibels.
Hint:
Since the sound decreases about 6 decibels every time the distance doubles, we can estimate the sound level at different distances from the stage like this:
1 metre = 100 decibels
2 metres = 94 decibels
4 metres = 88 decibels
8 metres = 82 decibels
16 metres = …
and so forth. Continue the pattern until you can estimate the sound level at 75 metres from the stage.
Answer:
b. 55-65 decibels