Sound waves propagate through air by causing disturbances or variations in air pressure. When a sound is produced, such as by a vibrating object or a speaker, it creates compressions and rarefactions in the surrounding air molecules, leading to the formation of a sound wave.
As the sound wave travels, it creates alternating areas of high pressure (compressions) and low pressure (rarefactions) in the air. During a compression, the air molecules are pushed closer together, resulting in an increase in air pressure. Conversely, during a rarefaction, the air molecules spread out, leading to a decrease in air pressure.
These variations in air pressure caused by the sound wave create a series of successive compressions and rarefactions, forming a pattern of oscillations that propagate outward from the sound source. The sound wave continues to travel through the air, carrying the energy of the sound.
As the sound wave interacts with the air, it causes the air molecules to vibrate back and forth along the direction of wave propagation. This vibration transfers the sound energy from the source to the surrounding air. The air molecules essentially act as a medium for the transmission of the sound wave.
When the sound wave reaches our ears, it causes the eardrum to vibrate, which in turn stimulates the auditory system, allowing us to perceive sound. The way in which the air molecules are disturbed by the sound wave determines the characteristics of the sound, such as its frequency, amplitude, and timbre.
In summary, sound waves affect the air by creating variations in air pressure, leading to compressions and rarefactions. These pressure changes propagate as a series of oscillations through the air, carrying the energy of the sound and allowing us to perceive it.