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What is Sound?
Sound is what we hear. Technically speaking, Sound is defined as a form of energy having the capability to propagate in air and water.
Sound is an energy medium which enables us to communicate with each other. What we speak is sound caused by the vibration of our vocal chords. We can hence clearly say that vibration is the main cause of creation of sound. Hence anything which vibrates always tends to produce a sound and tend to do in tandem with each other.
Before we move into the effects of sound on human life, let us know more about sound.
Our human ear has the capability to hear sounds in the range of 20 Hertz to 20000 Hertz. Sounds that occur lesser than this and higher than this cannot be heard by the human ear. Sound can be classified as two types based on its use to mankind.
- Sound that is useful to mankind like music, speech which we use for communication,
- Sound that is not useful to mankind like the sound from an aircraft, bursting of high intensity crackers, blaring sound speakers etc. We call this Noise.
We tend to like sound mainly based on its intensity or the sound level. This means that like sound too has a unit of measurement. We measure sound in its following areas
- Sound Pressure Level: The common measurement what we carry out for sound measurement. This is also a direct measurement quantity. This is a property which measures the pressure fluctuations of the sound. The basic unit for measurement of Sound pressure is dB (Decibels). The unit has three weightage scales. We will discuss in detail on the above scales in the next article.
- Sound Intensity Level: This is also a direct measurement quantity. This is a measure of the amount of sound energy flowing at a given position through a defined area. The unit for sound intensity is (W/m^2) Watts per Meter Square.
- Sound Power Level: This is a quantity calculated from the measurement of sound pressure or sound intensity measurements. This is a measure of the total acoustical energy emitted from a device. The unit of this is Watts.
We will look further into the measurement of each of these measurements in the forthcoming articles.
We basically measure sound to know its effects on the mankind. Sound tends to produce a soothing effect on our minds like music as well as a frightening effect like sound from an aircraft, cracker blast, etc based on its intensity.
A small figure showing the intensity of the sound levels in what we work and live in will help us to understand the importance of sound in our lives. Click here to see the levels of sound intensity. The reduction of sound levels will play a vital role in the quality of life we live in.
Sound and its Importance in Engineering
Sound Intensity Measurement / Measurment of Sound Intensity