Example 3: compensating for the failure of a classic law
Methodological guide for the acoustic study of rooms. Approach by models

Many of the models used to describe the behavior of sound in a room are based on statistical laws. This choice is easily explained by the fact that, beyond a critical distance, the dominant field is the reverberant field. However, this critical distance is always very small compared to the dimensions of the room (for the meeting room in the first example, it remains less than 1 m even after treatment).

All the laws relating to the reverberant field (starting with Sabine's formula) are based on the principle of homogeneous diffusion. However, homogeneous diffusion is rarely observed in reality, even in relatively regular rooms. In irregular rooms, we can therefore find ourselves in situations where the classical laws become grossly false. The simplest case of an irregular room is that of a long room (X >> Y, Z).