Here's why:

* Transverse waves involve oscillations perpendicular to the direction of wave propagation. Think of a wave on a string: the string moves up and down (perpendicular) while the wave travels horizontally.

* Longitudinal waves involve oscillations parallel to the direction of wave propagation. Imagine a spring: when you compress it, the coils move back and forth (parallel) as the compression travels along the spring.

Sound waves travel through a medium by causing particles within that medium to vibrate back and forth. These vibrations are parallel to the direction the sound is traveling.

Think of it like this:

* When you speak, your vocal cords vibrate, creating pressure changes in the air.

* These pressure changes cause the air molecules to compress and expand, creating a series of compressions and rarefactions.

* These compressions and rarefactions travel outward from the source, causing the air particles to vibrate back and forth along the same direction as the sound wave is traveling.

Therefore, sound waves are longitudinal waves, not transverse waves.