The social environments most people call “echo chambers” map entirely incorrectly to the metaphor of acoustic physics, whereas true “echo chambers” have the structure of something like a large cathedral…

…true sound absorption/anti-echo materials in contrast by definition include highly manifold structures with many internal divisions.

How does acoustic foam work? All we have to do to understand how does acoustic foam works is to look at the individual cell structure of the foam. You can see that the cell structure is open or porous in nature. This cell structure type allows for air to flow into the foam and enter the individual cells. Once it is in the cells, it moves around and this movement creates friction. We all know that friction can produce heat. If you have ever rubbed sticks together when camping to create a fire, you realize how friction works. Once the friction starts to produce heat, an energy transformation occurs. We do not lose energy, we change its form to heat.

https://www.acousticfields.com/how-does-acoustic-foam-work/

It is well known that the acoustic absorption capacity depends on the acoustic porosity content (open porosity). Indeed, scientists have focused on materials with interconnected porosity, especially foams made from polyurethane [1], [2], [3], [4], [5], [6], [7], [8]. It is essential to determine parameters such as the airflow resistivity, tortuosity and acoustic porosity to understand acoustic phenomena.

https://www.sciencedirect.com/science/article/abs/pii/S0167577X14000779

this is a structure that deadens echos