Abstract: A composite board having an excellent vibration-suppressing sound-shielding performance can be obtained by joining a plurality of board materials with each other by the intermediary of a tacky adhesive. This tacky adhesive contains, as its principal components, one or more kinds of polymers selected from the group consisting of natural rubber, synthetic rubbers, various resins (acrylic resin, silicone resin, etc.). A sheet-like base material such as a paper sheet can be used in association with the tacky adhesive layer in the composite board, and such type of composite boards have an excellent vibration-suppressing sound-shielding performance as compared to the composite boards in which the tacky adhesive layer is not associated with a sheet-like material.

Abstract: A perlite sound absorbing plate and a sound insulating wall constructed by arranging a number of said plates side by side and by assembling together into one integral body are disclosed. The plate is composed of a mixture including 1,000 cm.sup.3 by bulk volume of formed perlite particles each having a diameter of 0.1 to 7.0 mm, 100 to 140 g of cement, liquid rubber latex containing 5 to 20 g of solid ingredients and a suitable amount of water and produced by press molding with a compression ratio of 1.10 to 1.30. The wall is constructed by assembling a number of said plates each provided with a side groove with the aid of supporting columns and reinforcing plates, each having a ridge adapted to be engaged with the side groove of said plate.