A room acoustic investigation of an actor’s position and orientation for drama performances

This study is concerned with optimum positions and orientations of theatre performers when acting off stage. Five audience settings of a drama theatre; a proscenium, an arena and three extended stages have been numerically investigated after a calibration. An analysis of a human voice pattern in a free-field concludes that the sound pressure levels in the range of the azimuth angle [-50º, 50º] with respect to the performer’s frontal direction are equally loud. This holds irrespective of frequency and the elevation angle. Although this optimum speech aperture angle (OSAA) is based on the free-field speech directivity, fairly uniform spatial distributions of D50 were found within the OSAA range for most theatre settings. Among several orientations of the actor tested, an orientation based on the OSAA results in the highest speech intelligibility. For an actor on the extended stage, the verge of the stage gives the best results. When the actor performs among the audience in an U-shaped or arena configurations, the boundary of the acting area is generally recommended rather than the central region.