MJM Acoustical Consultants INC. has been retained by the Canada Mortgage and Housing Corporation to conduct a research project on the noise produced by plumbing installations in multi-dwelling buildings. The main objective of this study was to investigate the acoustical performance of difference plumbing installations using materials and techniques readily available in the construction industry. Over two hundred seventy-three tests were conducted in the acoustical laboratories of the National Research Council of Canada in Ottawa under the supervision of Dr. A.C.C. Warnock and under the direction of the undersigned.