The Nature of Sound The Nature of Sound By Federico Miyara Sound Waves Sound is created by a disturbance travelling in an elastic medium. For instance, when an excess pressure is produced on some region of the air, that region tends to expand towards the neighbouring zones. This, in turn, compresses those zones, creating a new excess pressure which will tend to expand next, and, again, a new excess pressure is further created.
Excess pressure is called sound pressure .
This kind of movement in which it is not the medium itself, but some disturbance that is travelling, is called a wave . There are many other types of waves, such as radio waves, light, heat radiation, the ripples on the surface of a lake, tsunamis, earthquakes, etc. When a wave is audible, it is called a sound wave . Acoustic waves travel usually at a given constant speed, which depends on the medium and environmental conditions such as temperature. This means that it takes one second for sound to go over a 345-meter distance.