Comments on ‘Absorption mechanisms for waterborne sound in Alberich anechoic layers’

The vibrational behaviour of Alberich-type absorbers is reviewed once more. Two types of resonance mechanisms are known to be present in such layered configurations. One is due to the radial motion of the hole wall and the other to the drum-like oscillations of the cover layer. The relative importance of these two mechanisms is discussed, and criticisms of an earlier paper of the author are answered, and are placed in proper perspective.