Sound Transmission: Glass vs. Wood Doors

[ananthu]

Homework Statement

when people speak inside a closed cabin with glass doors, sound is not heard outside where as with wooden doors it is heard outside. What is the correct explanation? Is it because, sound is not at all transmitted through glass, or, absorbed by the glass? What is the exact mechanism involved?

Homework Equations

The Attempt at a Solution

 

[mgb_phys]

Glass doors are almost airtight so you need the sound to be transmitted into the glass and then from the glass back into the air. The efficency of this transfer is something like the difference in density squared (not really but in simple terms) so very little energy gets into heavy glass and out again.

The wooded door probably doesn't seal well so the air (an the sound in the air) can go through the gaps. Also the air will couple to the light wood better