What is the Acoustic Impedance of Wool?

[Coolguynice]

Homework Statement

I need this to find the the reflective coefficient and multiply this by 100 to find the percentage of original energy reflected back however i cannot find the acoustic impedance of wool no matter how hard i try.

Homework Equations

Im using the reflective coefficient formula which reads as ((Z2-Z1))^2/((Z2+Z1))^2 where z is a sound impedance. In this case Z1 is the sound impedance of air and Z2 is the sound impedance of wool. I also found a formula to calculate acoustic impedance which reads as Z=density of material(pressure*speed of sound through the material) however it doesn't specify whether the pressure is a constant or not and like the acoustic impedance, i also cannot find the speed of sound through wool after all this time.

The Attempt at a Solution

Any help or directions to decent sources would be extremely helpful. I know exactly what to do but these lack of values is holding me back from finishing anything else. Any help would be greatly appreciated.

 

[gneill]

When you say "wool" do you mean natural fiber sheep's wool, or something like mineral wool or glass wool or fiberglass wool which are commonly used as acoustic insulation?

 

[Coolguynice]

Glass or fiberwool would be the best but honestly, at this rate i would be fine with any value regardless of the type of wool. Also thanks for replying.

 

[gneill]

You may have to do some prowling through the search results, but try Google with a keyword phrase like "Acoustic impedance table wool".