Stig Ingamansson’s Noise Control: Principles and Practice

B1 – Sound from Vibrating Plates – Size and Thickness

MAKE VIBRATING SURFACES AS SMALL AS POSSIBLE

An object with a small surface area may vibrate intensely without a great deal of noise being radiated.  The higher the frequencies, the smaller the surface must be to prevent disturbance. Since machines will always vibrate to some extent, noise will be reduced if the machinery parts and covers are kept as small as possible.

B2 – Sound from Vibrating Plates – Size and Thickness

DENSELY PERFORATED PLATES PRODUCE LESS NOISE

Large vibrating surfaces cannot always be avoided. The vibrating surface pumps air back and forth like the piston of a pump, causing sound radiation. If the panel is perforated, the “piston” leaks, and the pump functions poorly. Alternatives to perforated plates include mesh, gratings, and expanded metal.