Harvard Professors Develop Raid Siren

Mounted on the back of a truck, a new siren, developed by several Harvard professors in collaboration with the Bell Laboratories, was given a 20 minute test from New York's Manhattan Bridge, and officials pronounced it "one of the nation's leading sirens."

One of the projects of the National Defense Research Council, the siren problem was brought to Harvard by Dr. Harvey Fletcher, director of physical research at the Bell Laboratories under the arrangement whereby Harvard facilities are opened to research of this nature.

With the exception of some "deal spots" in lower Manhattan, the blasts were heard over a great part of the city, with sound readings running between 95 and 105 decibels. This compared favorably with the sound of an airplane motor at eighteen feet, which measures 115 decibels.

Headed by Dr. Fletcher, the project was studied by S. Smith Stevens, assistant professor of Psychology, and Dr. Hallowell Davis, associate professor of Physiology.