ABSTRACT
Sound inuences all of our activities. The human ear is capable of detecting waves carrying energies as low as 10−18 J. For comparison, the energy required to lift a paper clip up to a height of only one millimeter is one trillion times as great. This remarkably sensitive organ allows us to detect the immense variety of sounds in which we are constantly immersed; the snarling and barking of dogs, the mewing of cats, the chirping and singing of birds, the screaming of sea gulls, the crowing of roosters, the whispers of trees, the patter of rain, the thunder of storms, the ticking of clocks, the whir of machines, the crying of babies, the voices of singers, or the melody and harmony of music.
