Abstract :
With the aid of sound measurements made with an analyzing type of sound meter, it has been possible to ascertain the principal sources of noise in an electric power substation in a residential district and to reduce the noise to an unobjectionable level. The principal sources of noise were found to be an outdoor 6,000-kva transformer and the voltage regulators inside the station building; by replacing the noisy transformer with a quieter one and replacing the ventilating louvers in the regulator rooms with steel plates, the noise on neighboring properties was reduced to about 4 per cent of its original loudness.