Question

What is the importance of air in transmission of sound?

Answer 1

We know that sound travels in the form of waves through any given medium. It can travel through any medium and the speed at which the sound waves travels through the given medium depends on the nature of the medium. Thus we can say that medium is an important criteria for the propagation of sounds.

Complete step-by-step solution:
We know that sound is a mechanical wave which needs a medium for propagation, as it oscillates the particles of the medium to travel across it. The motion of the particles of waves, suggests that sound waves are longitudinal waves.
Consider a person from one corner of the room, calls to the other person on the other side of the room, then the disturbance causes a to and fro motion of the particles of air present in the room, which in turn pass the energy between them, and thus sound is heard from one corner to the other of the room.
Since air acts as a medium of propagation for sound waves, we can say that without air the sound waves do not get transferred from one corner of the room to the other.

Note: Only sound waves between $20\;Hz$ and $20\;kHz$ can be heard by the human ear and this range is called the audible range. However, ranges above $20\;Hz$ is called ultrasound which is used by dolphins and bats for communication and ranges below $20\;Hz$ is called infrasound and is used to monitor and study earthquakes and volcanoes. The ultrasounds and infrasound are not audible to the human ear.