The Little Theatre in New York City, with an auditorium forty-eight feet long and forty-nine feet wide, and with a ceiling twenty-eight feet high in front and twenty-three feet high in the rear, is a fine example of a theatre especially designed to carry the delicate shades of modulated tone with unusual precision. In this theatre, the front walls on either side of the proscenium opening are symmetrically curved and paneled, and the rear walls follow the curved line of the seats. In order still further to reduce reverberation, in each of the side walls are installed three 6 by 13 foot "acoustic felt" panels, and in the rear wall seven similar panels, two being 4 feet 5 inches by 13 feet; two 5 feet by 10 feet; two 2 feet by 4 feet, and one 8 feet by 7 feet. As will be seen by the illustration on Page 167 there are no stage boxes to lessen or destroy sound.
Professor Sabine, in his experiments for remedying the faults of the New Century Theatre, made photographic tests of its sound waves before and after correction. (See illustrations preceding this chapter.) To make these photographs a small model of the theatre as used, the actual sounds and their echoes being photographed by the Toepler-Boyes-Foley method as air disturbances passing through it.
The reproductions of the original sound waves and the new sound waves after a remedial canopy had been installed in the ceiling visually illustrate the possibility of acoustic correction. This canopy was oval in shape and somewhat larger than the ceiling oval which it replaced, and from which originally hung the central chandelier. It prevented disturbing sound reflections, and Professor Sabine declares that since this correction there are few theatres of its size and capacity in America as free from sound diffraction as this one.
The presence of an audience in a theatre usually improves its acoustics. Within the inclosing walls of an auditorium, where the distance traveled is not too great, the voice, rebounding directly from the ceiling oval which it replaced, and from which the ceiling and side walls, arrives almost simultaneously with the direct sound, each spoken syllable being audibly strengthened as a single sound by the resulting "consonance."