METHOD FOR ESTIMATING AUDIBILITY AND EFFECTIVE LOUDNESS OF SIRENS AND SPEECH IN AUTOMOBILES

By using the parameters for the [human] ear and the equations for a communication theory model of the behavior of the ear, a family of masking curves were drawn up which were applied to the conditions prevalent in automotive vehicles. From the behavior of the ear and its ability to resolve sounds in noise, estimates were made of the conditions under which sirens and speech communications will be audible within motor vehicles moving in traffic, and some estimate was also made as to their potential for attracting notice. These quantities can be read off by graphic techniques. Examples of their use were given.