How does the sound produced by a vibrating object in a medium reach your ear ?
Hint: Sound waves need medium to travel in order to reach detectors or sensors. Sound propagates because of continuous compression and rarefaction happening in the medium particles. In the case of humans, detectors or sensors are our ears which receive sound waves resulting in vibration of tympanic membrane thus causing the sensation of hearing.
Complete answer: Sound is produced whenever there is certain disturbance in the medium. The disturbance results in vibration in the medium which propagates and reaches to our ear and hence we are able to acknowledge it. In a material medium whenever a disturbance is created or suppose a vibration source is introduced it results in compressing of air particles and thereby increasing the density locally.
Compressed particles collide with each other thereby expanding and reducing the density, but this expansion which we term as rarefaction results in compression of the next layer of medium particles and hence again results in compression, and this cycle keeps on repeating.
This continuous compression and rarefaction of particles in the medium resulting due to a vibrating body or certain disturbances, produce sound which traverses the medium and reaches our ear. Example: When a tuning fork is vibrated in air, it creates a random motion in air particles in the form of compression and rarefaction which propagates the medium, reaches our ears and we are able to acknowledge it.
Note:Sound waves which we are talking about here are termed as mechanical waves. Mechanical wave is a wave which needs medium to travel or in other words waves which are not capable of transmitting its energy in vacuum. Like here we won’t be able to hear tuning fork in vacuum since the wave or pulse being produced by vibrating needs medium to travel.