While sound waves can exert a force on objects, they are generally not suitable for propelling objects through the air in a practical way. Here's why:
Sound waves propagate through the air as pressure variations, compressions, and rarefactions. These pressure fluctuations do create a force, but it is generally too weak to produce significant propulsion. The forces generated by sound waves are typically much smaller compared to other means of propulsion, such as those used in aviation or rocketry.
Sound waves travel in all directions from their source, rather than being focused in a specific direction. To propel an object effectively, you need a directed force that can push it in a specific direction. Sound waves, being omnidirectional, would exert forces in all directions, making it challenging to achieve controlled and directed movement.
The energy required to generate sound waves is usually inadequate for producing substantial propulsion. The amount of energy needed to create sound waves capable of propelling an object with significant speed and force would typically be impractical or inefficient compared to other propulsion methods.
That being said, there are experimental concepts that involve using high-intensity sound waves, such as acoustic levitation or acoustic propulsion, to create localized forces and movement. These methods utilize intense sound fields and specific acoustic principles to manipulate objects in controlled environments. However, they are still limited in their application and have not been developed for widespread use in propelling objects through the air.
For practical purposes of propulsion, other means such as mechanical propulsion (e.g., engines, rockets), aerodynamic forces (e.g., wings, propellers), or electromagnetic propulsion (e.g., electric motors) are commonly employed instead.