How does the sound produced by a vibrating object in a medium reach your ear ?

Solution:
Air is the most common material through which sound propagates. When a vibrating object like prongs of tuning fork move forward, they push the molecules of the air in front of them. This is turn compresses the air, thus creating a region of high pressure and high density called compression. This compression in the air travels forward. When the prongs of the tuning fork move backward, they create a region of low pressure and low density in the air, commonly called rarefraction. As the tuning fork continues to vibrates, it produces a series of successive compressions and rarefractions in the air, thus, propagating sound through the air which finally reaches our ears.