Acoustic impedance

Have you ever tried to whisper into a wall and see that it doesn't work very well? That's because the wall has a different "resistance" to sound waves than the air does. This resistance to sound waves is called acoustic impedance.

Think of it like trying to swim through water versus trying to swim through honey. The honey is thicker and stickier, so it's much harder to move through it than through water. Similarly, the air has a certain "thickness," and materials like walls or water have a different thickness or resistance to sound.

When sound waves travel through different materials, their strength changes based on the impedance of that material. So if you're trying to listen to music through a wall, the sound waves will become weaker and quieter because the wall is impeding the sound.

Scientists can measure acoustic impedance using a special unit called a "rayl." This helps them understand how sound behaves in different materials, which is important for things like designing speakers or understanding how sound travels through different parts of the body.