Master Handbook of Acoustics, Sixth Edition, 6th Edition

CHAPTER 8

Refraction

At the turn of the twentieth century, Lord Rayleigh was puzzled because some powerful sound sources, such as cannon fire, could be heard only short distances sometimes and very great distances at other times. He calculated that if all the power from a siren driven by 600 horsepower was converted into sound energy and spread uniformly over a hemisphere, the sound should be audible to a distance of 166,000 miles, more than six times the circumference of the earth. However, such sound propagation is never experienced and a maximum range of a few miles is typical.

When dealing with sound propagation, particularly outdoors, refraction ...