Sound wave is a Longitudinal Wave. When Sound Wave travels through air it will create expanding or shrinking column of airs called Rarefraction and RareExpansion.
- Sound Wave | || | ||
Sound Wave Characteristics
- Sound does not exist in vacuum .
- Sound wave requires medium of matter to spread itself . Sound wave travels through any medium Solid , Liquid , Gas
- The speed of Sound wave varies with Pressure and Temperature of the medium . Sound wave travels at a speed v = λ f . At Standard Pressure & Temperature in air the speed is calculated equal to v = 333 m/s
- Sound Wave that is audible to human ear is in the frequency range 20Hz - 20KHz .
When Sound wave travel through a medium if there is a blocking object that has a height greater than the wavelength of sound wave . Sound wave will suffer from the following effects
- Sound wave being reflected back to the medium it comes from and can create interference with other wave in the medium
- When two sound waves travel toward each other will interfere either Constructively or Destructively to produce different sound interferences like Noise, Echoe, Intermittent, No sound
In Tele Communication, in order to carry Sound wave over a long distance sound wave must be mixed with a high frequency carrier wave in a process called Modulation .
In Radio Communication, There are 3 modulations methods are used in mixing Sound wave and Carrier wave namely AM - Amplitude Modulation, FM - Frequency Modulation, PM - Phase Modulation.
In analog electronics , AM and FM is widely used . In digital electronic, PM is used