What are the three acoustic variables that characterize sound waves?

The three acoustic variables that characterize sound waves are pressure, density, and particle motion (which can also be described in terms of distance). These variables are essential in understanding how sound propagates through different media.

Pressure relates to the force exerted by sound waves on a surface area and is a direct measure of the acoustic energy transmitted through a medium. Density pertains to the mass of the medium per unit volume, which influences how sound travels through that medium. Lastly, particle motion indicates how particles in the medium vibrate as the sound wave passes through. This vibration is what creates the compressions and rarefactions necessary for sound propagation.

By understanding these acoustic variables, one gains insight into the fundamental behavior of sound waves and how they interact with various materials, which is crucial for applications in sonography.