Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound vibrations cause waves of pressure which lead to some level of compression and rarefaction in the mediums through which the sound waves travel. Sound energy is, therefore, a form of mechanical energy; it is not contained in discrete particles and is not related to any chemical change, but is purely related to the pressure.
Sound energy is typically not used for electrical power or for other human energy needs, because the amount of energy that can be gained from sound is quite small. Energy is the amount of work that can be performed by a given force, system, object or anything else capable of performing work. Work is simply defined as the ability to cause change in a system; this can involve anything from a change in location to a change in heat energy. The amount of work that can be performed by common, day- to- day sounds is quite small. So sound is not often thought of in terms of the energy it contains. Sound energy does, however, exist as the vibration waves of sound cause change, even if that change is small. Rather than measuring sound in typical units of energy, such as joules, scientists and others tend to measure it in terms of pressure and intensity using units such as pascals and decibels. Sound measurements are by their very nature, relative to other sounds that cause more or less pressure.
Usually, sound is described in terms of the way, it is perceived by healthy human ears. A sound that produces 10 pascals of pressure at an intensity level of about 135 decibels, is for example, commonly described as the threshold of pain. It is of adequate pressure and intensity, often combined into the common term ‘foudnes^’ to cause physical pain. Sound energy is closely related to the ability of the human ear to perceive sound. The wide outer area of the ear is maximized to collect sound vibrations. Sound energy is amplified and passed through the outer ear, striking the eardrum, which transmits sounds in the inner ear. Auditory nerves fire according to the particular vibrations of the sound waves in the inner ear, which designate such things as the pitch and volume of the sound.
Sound energy is a wave of vibrations in a material. Depending on how many sound waves come in a certain period of time, the pitch of the sound that we hear moves up and down. This is called the frequency. Also, depending on the strength of the waves, the sound is loud or softer. Sound travels at different speeds depending on the material, it is travelling through. It travels the fattest through solids because they are so dense. It travels slower through liquids and gases, because they are not as dense.
When we speak of energy, a lot of things come to mind. Whether or not we know its existence, energy will always be one of the concepts in science that everyone will be dealing with. As defined by most scientists, “energy is the capacity to produce work’ where work is done when a transfer of energy is made for an object to move at a certain point. Defined as such, energy can be recognized into various forms, which could be mainly classified into kinetic or potential. Aside from light, mechanical motion and thermal energy, one additional form of evidence that proves the existence of energy is sound energy.
(The writer is indebted to Dr Sarat Chandra Pattanaik who has been pursuing scientific research on language, education, sound, culture, art and science etc for last 50 years to write this article)