Saturday, 27 July 2013

Sound - A Wave




Sound is simply defined as a sequence of waves transmitted through a compressible medium like gas and liquids. Different types of sounds have different wave lengths, speed, intensity and different frequencies which are measured in Hertz (Hz).  

Study of Sound





 






Study of sound is often known as acoustics. This is important for architectural engineers, sound detecting devices, musical instruments and studying how animal react with different types of sounds.
 

Properties




Sound has various properties. It has wave lengths, intensity, speed and frequencies. Sound is transmitted when a medium gives energy to a particle and that particle gives it to the next and so on. This process is very fast on solids as the molecules are close to each other and slowest in gases and molecules are far away from each other.

    Speed


Speed of sound depends upon the temperature, air pressure and the fundamental property of the medium through which it is passing. In air, sound travels at a speed of 332 m/s. For Example, Sound travels fastest in solids and the slowest in gases and travels medium in liquids. Speed of sound in air is 1,230 km/h and in liquids, it is 5,337 km/h and in solids, it is approximately 21,460 km/h.

Amplitude

Amplitude is the displace of a vibrating body from its original position. A body producing high amplitudes produces high sounds which we can hear from far away.

    Frequency







Sound has different frequencies. Frequency is the number of vibrations produced by a body in a second.Sound audible to human ear can have frequencies from 20 Hz to 20000 Hz. So, sound less or more than this range is not audible to human ear. It. depends upon the wave length of the wave. If the wave length is short, it produces more frequencies and if it long, it produces less frequencies.

Wave Length




Wave Length is the distance between the points where the wave's shape repeats. These points can be between the crests and the wave crossing zero or troughs. When wave length is short, that means more waves and high frequency. If wave length is long then less waves and frequencies.

Echo



Sometimes, when we say something, that sound is again and again heard in decreasing manner. That is actually the reflection of sound in a room or any other place where the distance is from 17 mm to 17 m as human ear's audible range is from 20 Hz to 20000 Hz. When sound is produced, it travels to the front and touches the wall of the room. As the wall is solid and strong, the molecules absorb very less energy as they are close together. The rest energy is reflected back. This process continues till the wall absorbs all the energy from that sound. That's why we hear multiple echos, but it becomes less audible when we hear it again and again.

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Now, see the following video from youtube that shows a bit about Musical Acoustics and explains frequencies and wave lengths:

                                              

Please Comment about this blog. This is a newly started blog. I wish to view viewers suggestions and tips. Thank You.

                                                                                                                       Article by - M. Santosh
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