Why are sound waves called mechanical waves?

Explanation

Because, medium is essential for propagation of mechanical waves. When sound waves propagate in the medium, disturbance moves in the medium. Disturbance means intervention produced in the medium.
Now, due to the disturbance produced particles of the said part oscillate. Now these oscillated particles transmit this effect to the nearby particles due to the property of elasticity of the medium.
So, these nearby particles start oscillating Thus, during propagation of sound waves in air, oscillations of particles are seen which are necessary for propaagation of mechanical waves.So sound waves are called mechanical waves