Since the first report by Wood and Loomis in 1927 …show more content…
Frequency is the number of cycles occurred in one second, measured in Hertz. Amplitude is the height of the wave, and it is a measure of the amount of force applied over an area, expressed in Newton per square meter (N/m2). Amplitude is directly related to the acoustic energy or intensity of a sound, which is the amount of acoustic energy transmitted across unit area per second, expressed in Watts/surface area. Both amplitude and intensity are related to sound's power. Assuming a sound wave as an expanding sphere of energy, power is the total amount of kinetic energy contained on the sphere’s surface . Acoustic waves travel through a medium, with a defined speed of propagation or velocity. The acoustic wave propagation through a medium depends on the elastic properties and mass density of the medium itself. US and sound waves propagates in fluids as well as solids, and the sound waves travel efficiently through fluids which includes closely compacted molecules. US propagate as longitudinal wave, where the molecules in the medium oscillate in the same or opposite direction of propagation of the waves. Longitudinal waves are also