Question

There is evidence that elephants communicate via infrasound, generating rumbling vocalizations as low as 14 Hz that can travel up to 10 km. The intensity level of these sounds can reach 102 dB, measured a distance of 4.5 m from the source. Determine the intensity level of the infrasound 10 km from the source, assuming the sound energy radiates uniformly in all directions.

Answer 1

The intensity of spherical sound waves at distancer Paverage power 4.5m r, 104m = 4m",12-47,2 giving 1,--21) 月-10 log |--| = 102dB -10 log | | --| 그 = 10log| | +10log -20 log |--|+10log 4.5 - 20log +1 +102dB 10 66.935+102dE = 35-065dB B. = 35-065dB