Sound is a sensation generated in the ear.
From the Latin sonitus , a sound is a sensation that is generated in the ear from the vibrations of things. These vibrations are transmitted through air or other elastic medium .
For physics , sound implies a phenomenon linked to the diffusion of a wave with elastic characteristics that produces a vibration in a body, even when these waves are not heard.
What is sound
Sound audible to humans is formed by variations in air pressure, which the ear converts into mechanical waves so that the brain can perceive and process them.
When sound propagates, it transports energy but not matter. The vibrations are generated in the same direction in which the sound diffuses: we can speak, therefore, of longitudinal waves .
It has been estimated that sound, when a temperature of twenty degrees Celsius is recorded, reaches a speed in the air of three hundred and forty meters per second. It should be noted, therefore, that the speed achieved by sound is higher in solid media than in liquid media, and that it is higher in the latter than in gases.
The acoustic power
Acoustic power , on the other hand, is the amount of energy in the form of waves that a certain source emits per unit of time. This power depends on the amplitude (the largest variation in displacement of the wave motion).
The main qualities of sound are pitch (low, high or medium, depending on the frequency of the waves), duration (the time in which the sound is maintained), timbre (its characteristic feature) and intensity (the amount of energy it contains).
When sound propagates, it carries energy, but not matter.
Sound effects for audiovisual productions
Cinema tends to stand out mainly for its visual achievements, whether it is large computer-generated worlds or mythical beings of colossal proportions that have been mixed with reality in such a careful way that they seem to be there . Depending on the musical sensibility, the pieces composed for the soundtrack are also respected, and often become myths.
However, there is one aspect of movies that generally goes unnoticed: sound effects . Many people probably assume that if they hear footsteps on dry leaves, or the howl of a wolf, or the noise produced by an avalanche of snow that attacks the trees and cabins in its path, these have been recorded naturally. As surprising or incredible as it may seem, most of these sounds are "manufactured" in specialized studios, which use all kinds of tricks to bring to life a war, a gigantic robot or nature itself.
Thinking about a blockbuster, it is fascinating that a scene in a forest requires effects created in a closed room full of musical instruments, synthesizers and computers to have sound and generate that feeling of immensity, of peace, to reproduce the songs of birds, the blow of the wind caressing the leaves.
The most interesting thing about the effects creation process is the search for the right sound for each case; All kinds of elements are used, from objects that people usually have in their homes, such as glass glasses, cutlery, pieces of paper and cardboard, to whatever the imagination dictates to the creatives, who are in charge of such a difficult task. as ignored . Decisions are made that the audience would not consider possible or necessary, since many times the same action that occurs on the screen is avoided in order to opt for an alternative path that, although it may seem absurd, generates a more effective and impactful result.