The acoustic enclosure modifies the conditions of sound propagation. Sound bounces off the walls, and the waves overlap each other. At long distances, the time it takes for the bounces to reach the listener becomes noticeable, and undesirable effects such as echo and reverberation appear, reducing intelligibility. It is influenced by the materials of the walls, floors, and ceilings, as well as the furnishings and the listeners themselves, and requires careful speaker placement, audio signal processing, and controlled power application.
We are talking about three types of fields:
- Direct field is the area where the sound reaches the listener directly.
- Reflected field is the area where the sound reaches the listener out of phase after having been reflected off an obstacle.
- Diffuse or reverberated field is the area where the sound reaches the listener after multiple reflections and their corresponding phase shifts.
