Talking about the three conditions that must be met to form a diffuse sound field

Whether it’s a stage or a large-scale speech hall, a scientifically designed sound reinforcement system is needed. Now we can use stage sound equipment to achieve this purpose, but when we didn’t have these equipment before or didn’t want to use these equipment, the sound can be diffused perfectly by the design of the venue. Go to the purpose of the entire venue? This is feasible. Like the previous royal worship venues and ancient Greek circular conference halls, they have this function, which involves the knowledge of sound diffusion and reverberation environment. As long as you understand this knowledge, you can reduce modern sound reinforcement. The sound can be diffused perfectly without the use of sound reinforcement equipment or equipment. The statistical research of indoor sound field is based on the analysis of indoor reverberation process as its main content. When statistical acoustics is used to analyze the indoor sound field, the first condition to be met is that the sound field must be a diffuse sound field. It can be seen that diffusion and reverberation have a very close relationship. The reverberation can be described as follows: when the indoor sound field is stable, the sound source stops sounding, and the phenomenon that it continues due to multiple reflections or scattering of the sound is called reverberation. This phenomenon is an important feature of the sound field in a closed space (indoor). Consider an extreme situation. Imagine a beam of sound waves (represented by a sound ray) propagating in a large room with an irregularly shaped rigid wall. Obviously, this sound beam is before reaching the boundary surface (wall, ceiling or ground); it travels in a straight line. Once it reaches a certain boundary surface, it reflects according to the law of reflection. The reflected sound beam will change its original propagation direction and continue to propagate. After a certain propagation distance, it reaches another boundary surface, and reflects again, and continues to propagate forward in the new propagation direction, and so on. For a large room with irregular shapes, the incident wave in any direction can always be changed into a reflected sound propagating in a specific direction after several reflections. Since the sound waves are continuously reflected on each reflecting surface in the room and continuously change its propagation direction, this kind of sound field that enables sound waves at any position in the room to propagate in all directions is called a diffuse sound field. What is said here: 'Diffusion' has a clear. Physical meaning. Strictly speaking, the diffuse sound field must meet the following three conditions: (1) The sound energy density in the room is uniform, that is, the sound energy density is equal everywhere; (2) The probability of sound energy transmission in all directions in the room is equal; (3) From each room in the room The phase of a sound wave arriving at any point in its direction is random. In such a sound field, the sound waves will not 'cluster' invariably in either the spatial position or the propagation direction, but gradually expand and spread out as the propagation process progresses until it fills the entire space. In all directions.