Question

A sound power level reading of 127 dB was taken near a construction site
where chippers were being used. When all but one of the chippers stopped working,
the sound power level reading was 120 dB. Estimate the number of chippers in
operation when the reading of 127 was obtained. Assume that the sources
may be treated as ideal point sources located at the same point.

Answer 1

7 dB higher sound level (initially) corresponds to an intensity ratio I1/I2 given by

10*Log(10)I1/I2 = 7

Log(10)I1/I2 = 0.7
I1/I2 = 10^0.7 = 5.0

There were 5 chippers working initially

Answer 2

thanks!