ABSTRACT
To achieve this it was necessary for electroacoustics to reach a sufficient level of development. Before this many of the modern tasks of sound reinforcement engineering could be fulfilled either not at all or only by means of room acoustics or other technical means. In churches, for example, the pulpits were provided with canopies that produced additional reflection to amplify and project the human voice. Acoustic funnels or speaking tubes were already widely used in antiquity [2.1], and in shipbuilding long tube systems were commonly used for transmitting speech. Many signals were transmitted by means of large and small bells or horns. Stage effects were produced by means of special devices such as wind machines, or metal plates for simulating thunder.
