Abstract :
NOISES ORIGINATING from electrical machinery are of two general types, namely, direct air noise, and noise transmitted through the machine foundations to the framework of the enclosing structure. (A. L. Kimball, Journal of the Acoustical Society, Vol. 2, No. 2, Oct. 1930, pp. 297–304.) Disturbances of the latter type often may be reduced by a properly designed elastic support between the machine and building.
