Acoustics (Theatre). In a dwelling, it is desirable to a short but detectable reverberation time. We are now talking about noise. The noise can be transmitted through multiple pathways. Through the air or through a solid medium in which part of the sound it will reflect, some will be absorbed, and the remainder transmitted through the object.
The amount of sound reflected, absorbed or transmitted depends on the properties of the object, its shape, thickness and method of mounting, as well as the angle of incidence and the incident sound wave. The sound to move away from the source of noise intensity level decreases by 6 dB each time is twice the distance from the source in a free field. No less important are the materials: materials, in fact, in acoustics can be used to reduce the time of reverberation of a room or used as a barrier to reduce the intensity of the sound that travels from one point to another. Perhaps the most important of these materials are porous materials, which are constituted by a solid structure within which there is a series of cavities or pores interconected among themselves and with the outside world. Porous materials include rock wool, foam polystyrene, carpets, etc.
To modify the reverberations, the architect has two types of materials to cover surfaces in a room: that reflect sound and those who absorb it. The soft materials such as cork or felt absorb most of the sound that strikes them, although they may reflect some low frequency sounds. Hard materials such as stone or metals reflect almost all sound that reaches them. The acoustics of a large auditorium can be very different when it is full and when is empty: empty seats reflect the sound, while the audience absorbs it. In the majority of cases, the acoustics of a Hall is satisfactory if achieved an appropriate balance between sound-absorbent and reflective materials.