Question

how is sound produced

Answer 1

Sound is produced when something vibrates. The vibrating body causes the medium (water, air, etc.) around it to vibrate. Vibrations in air are called traveling longitudinal waves, which we can hear. Sound waves consist of areas of high and low pressure called compressions and rarefactions, respectively.

as we speak, we push the air particles near our lips. therefore the particles present our lips pushes the adjacent particle, hence we see that the direction of disturbance of particle and direction of propagation of wave both are parallel to each other.

here's the diagram which will help you relate.