The Noise-Reduction Manual was prepared under the auspices of the U.S. Office of Naval Research and was originally intended to constitute the introductory sections of a more extensive study of noise-reduction problems encountered aboard ship. There is a sustained emphasis on the practical techniques for the reduction of airborne noise, the treatment of each problem tacitly deprecating the need for, and even the practical value of, mathematical investigation of noise sources and noise fields as compared to the greater importance of careful acoustical measurements designed to direct the proper...