MO-74-04-3 -- Noise Reduction by Vibration Isolation

Noise reduction by vibration isolation primarily concerns reducing the forces and motions transmitted to noise radiating surfaces. Machinery noise problems, as shown in Fig. 1, may be caused by a slde panel of the machine being excited by transmitted machinery motion or by an outside wall surface being excited by transmitted forces from the machine. Direct connection of the machine to the noise radiating structure allows very efficient transfer, while vibration isolators placed at convenient locations between the source of the vibratory excitation and the radiating surface will materially reduce the transmission and noise radiation.

The effectiveness of the isolator is measured by the reduction of the transmitted forces or motion from the excitation.