Exhibitors Herald and Moving Picture World (Oct-Dec 1928)

102 BETTER THEATRES SECTION OF October 27, 1928 A CAREFUL analysis of the comments by prominent theatre architects on the four questions submitted by the editor and published in the September 1 issue of Better Theatres reveals a wide diversity of opinion on the general subject of acoustics in relation to talking picture theatres. The theatre owner who contemplates installing sound film reproduction equipment is apt to be bewildered and even appalled by the expense which such an undertaking would apparently contemplate. Let us, therefore, examine these questions and answers from the standpoint of the acoustical engineer and from the standpoint of this very exact and practical science known as Architectural Acoustics. For the sake of refreshing the memory, we will repeat the four topics that were discussed. No. 1 — What effect will synchronized pictures have on the acoustics in building the theatre of the future? As a matter of fact, the use of synchronized pictures should have no extraordinary effect on future theatre building. A theatre is built primarily for entertainment purposes and if it is to fulfill this function successfully, it should be good acoustically. This has been true of the motion picture theatre just as much as the legitimate theatre for drama, due to the constantly increasing use of presentation programs and incidental orchestral features. The science has been available to all architects for years and the widest conceivable publicity has been given the practical application of the science to the design of theatres. Many theatres fall short of what might be termed perfect acoustical conditions only because of carelessness or indifference on the part of some architects, and their failure to take advantage of the science. The fact is, that poor acoustical conditions will only become noticeably apparent in many theatres as talking pictures are introduced. This is due to the somewhat different standards of what constitutes good acoustics for speech and for music. Large theatres are apt to be very reverberant, particularly if less SOME COMMENT on the SOUND PICTURE SURVEY By R. V. PARSONS * Acoustical Engineer, John* Manvillc Corporation, New York City. Pictures illustrate acoustical properties Theatre, Detroit. new Fo.\ than capacity audiences are in attendance. Reverberation, of course, is the prolongation of sound in a room due to its continued reflection for an appreciable length of time after the source of sound has ceased, and it results in the blurring or running together of the syllables of speech and the notes of music Where the source of sound heretofore has been that of an orchestra or organ only, the effect of reverberation has been simply to provide a blending of notes that in many cases was not unpleasant. We must not overlook the fact that the standards of good acoustics after all are based on the consensus of public opinion, and public opinion is more or less swayed and formulated by the conditions with which it has to contend. Expressed in another way, we have to a certain extent become "used" to conditions which, while not perfect still are not so flagrantly bad as to be objectionable. However, when speech is introduced in these same reverberant theatres, a more precise standard becomes necessary because any blurring or running together of the syllables of speech makes audition very difficult, if not impossible. Good acoustics demands that each syllable of speech shall stand out clear and distinct; that the speech shall reach auditors sufficiently loud to be heard and understood with comfort, and the speech or music shall not be disturbed by extraneous noises. These should be the standards for theatres and auditoriums of every character, so that as a matter of fact, the effect of synchronized pictures will simply be to bring about a more rigid adherence to these known and accepted standards of good acoustics. It should be continually borne in mind that the acoustics of any theatre or auditorium, depend upon three factors, and three factors only — the size, shape and materials comprising the interior finish, which latter would include furnishings and the audience. When the acoustical problem can be approached in advance of construction, all these factors can be manipulated to provide good acoustics. Changes can be effected in shape to direct reflected sound so as to provide a well distributed degree of loudness or inten (Continucd cm papr 131)