The Effectiveness Of Sonic Outdoor Warning Devices Final Report

Sonic outdoor warning devices were used extensively in World War II to alert the population for air raids. On the assumption that sufficient information exists on the effectiveness of different types of sonic outdoor warning devices used in World War II, the Federal Civil Defense Administration asked Stanford Research Institute to combine this information on effectiveness with information from psychological and acoustical studies to determine the best type of warning devices for present installations. This study was initiated to compare the coverage of various type signals and to provide information to the Federal Civil Defense Administration and local civil defense units that will be helpful in planning an effective air-raid warning system.