The acoustic effects of the audience in the modern use the of ancient theatres

The ancient theatres are used in modern age for different kinds of shows. Today the ancient theatres have been returned to be the center of cultural activities during the summer seasons. Although many shows do not achieve the success of the critics and of the audience due to the weak acoustics of the theatres. Often the audience criticizes the acoustics, because they consider them lacking for the spoken comprehension and for the weakness of the music. An important aspect is the presence of the audience in the cavea, so it is important to understand whether this has a negative role in the overall acoustics of the theatre. The presence of the audience in the cavea involves variations of the room’s acoustics characteristics. The acoustic measurements are very difficult to carry out when there are people in the theatre. So it is possible to simulate the presence of the audience, in a virtual way, by using a software for architectural acoustics, in which the presence of the audience is simulated changing the value of the absorption coefficient of the surfaces of the cavea. The analysis of the numerical simulations show that the influence of the audience on the acoustics of theatres varies depending on the geometry of the theatre, and by the fraction of area of the cavea occupied by the audience.