Impact of radiated energy on the environment
Sound energy exchanges between several rooms - Industrial site Applications

Another consequence of the relationship e₂ = k₂ e₁ appears in predictive studies of noise transmission in the environment.

Determining sound levels in a room with known absorption characteristics enables us to predict sound levels at different points in the environment.

To determine the sound level at a point P outside a room containing an omnidirectional source located at M (figure 3).

The room has an opening of area S, which we'll assume is far enough away from the source that we can neglect the component of the direct field compared with that of the reverberant field.