What is sound ?

What is sound ?

Sound is a energy that can be hear by human's and animals.

The sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.

Sound is one of the important senses of the human body. 

The propagation of the sound wave is not possible through the vacuum. The medium here can be gas, liquid or solid.

Humans can hear sounds ranging from 20 Hz to 20 kHz.

Ultrasound

Sounds with frequencies above the range of human hearing are called ultrasound.

The sound waves of frequency greater than 20 kHz are called ultrasonic sounds.

Bats, praying mantis, dolphins, dogs, frogs, toads, etc. communicate via ultrasonic sounds.

Infrasound

Sounds with frequencies below the range of human hearing are called infrasound.

The sound waves of frequency below the range of 20 Hz are called infrasonic sound.

Rhinos, hippos, elephants, whales, octopuses, pigeons, squid, cuttlefish, cod, Guinea fowl, etc. communicate via infrasonic sounds.

Sound waves fall into three categories: longitudinal waves, mechanical waves, and pressure waves.

Longitudinal wave

Longitudinal waves are waves where the displacement of the medium is in the same direction as the direction of the travelling wave.

Mechanical wave

Mechanical wave is a wave that is not capable of transmitting its energy through a vacuum. 

Mechanical waves require a medium in order to transport their energy from one location to another.

Pressure waves

Pressure waves are the longitudinal waves which involve changes in volume and pressure during their propagation through a medium.

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