Here's how it works:

* Sound is a vibration: When something vibrates (like a drumhead or your vocal cords), it causes the air molecules around it to vibrate as well.

* Compression and rarefaction: These vibrations create areas of high pressure (compressions) where the molecules are close together, and areas of low pressure (rarefactions) where the molecules are farther apart.

* Wave propagation: These compressions and rarefactions travel outwards from the source, forming a sound wave. The air molecules themselves don't travel far, but the disturbance (the compression and rarefaction) moves through the air.

So, while the air molecules vibrate back and forth, they don't travel long distances. It's the disturbance, the wave of compressions and rarefactions, that moves forwards.