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The evolution of the world has been carried out from a relatively silent atmosphere to that one extremely noisy that we know today. The human ear is carried to close themselves, psychically, and to exclude the sounds that they upset it. Main task of the acoustic systems today is above all the isolation, from the outside towards the inside, an inside to the other. A musician cannot herself be allowed too much strong noises, but not even its public. A planner of control systems, in the actual musical production, must attend to isolation as far as the corrected dimensioning, in musical sense, of spaces, often employing a big part of the efforts for the first one to penalize the second.

To compensate the architectonic errors, to the ends of sufficient a sonorous calibration, is a process often much more expensive than one intelligent architecture. In each and every sonorous atmosphere that we find ourselves to live are defects necessary to compensate, in the search of a healthy environment. In the fifth book, part of the ten parts of “de architectura”, Vitruvio introduces the notion of the use of “resonant vases” in order to improve the quality of the sound in the theatres. These vessels, they must be integrated in the structure of the building, are true and tested cases of resonance, if well tuned they will be in a position to rendering a fuller and powerful sound.

In the mosque of Shah Abbas in Isfahan they have been used, likewise in the XV century small chapel in Pleterje, Slovenia between Ljubljiana and Zagreb, where they have been employed to absorb a frequency band, between 80 and 250 Hertz, to avoid a time of riverberazione that would have been way too long. The control of the duration of the time of reverberation is in fact one of the priorities in the planning of an acoustically important building. The duration of reverberation removes clarity and definition to the events and, when it is not understand as a musical effect, cause confusion and disorder.

If we assess in 2,30 second the time of ideal reverberation of an empty room, we discover that the value is that the Gewandhaus di Lipsia had, before being razed to the ground in the strafing of the 1944. W.C. Sabine, in front of the requirement of an auditorium larger a 70% more than Lipsia, succeeded in maintaining the same time also in its plan for the Symphony Hall di Boston, probably the best concert hall in north America, open in 1900. A determining experience and a much simple one for the development of a greater acoustic attention are just the perception of the time of reverberation during listening.