Room acoustics describes how sound behaves in an enclosed space.

The way that sound behaves in a room can be broken up into roughly four different frequency zones:

The sound wave has reflections at the walls, floor and ceiling of the room. The incident wave then has interference with the reflected one. This action creates standing waves that generate nodes and high pressure zones.

In 1981, in order to solve this problem, Oscar Bonello, professor at the University of Buenos Aires, formulated a modal density concept solution which used concepts from psychoacoustics. Called "Bonello Criteria", the method analyzes the first 48 room modes and plots the number of modes in each one-third of an octave. The curve increases monotonically (each one-third of an octave must have more modes than the preceding one). Other systems to determine correct room ratios have more recently been developed

After determining the best dimensions of the room, using the modal density criteria, the next step is to find the correct reverberation time. The reverberation time depends on the use of the room. Times about 1.5 to 2 seconds are needed for opera theaters and concert halls. For broadcasting and recording studios and conference rooms, values under one second are frequently used. The recommended reverberation time is always a function of the volume of the room. Several authors give their recommendations A good approximation for Broadcasting Studios and Conference Rooms is: TR[1khz] = [0,4 log (V+62)] – 0,38 TR in seconds and V=volume of the room in m³ The ideal RT60 must have the same value at all frequencies from 30 to 12,000 Hz. Or, at least, it is acceptable to have a linear rising from 100% at 500 Hz to 150 % down to 62 Hz