Dependence of sound insulation of building constructions on the acoustic properties of materials

The article deals with some acoustic properties of materials that have an impact on the sound insulation of building constructions, including sound absorption (abatement). These are namely, the capacity of materials to absorb, i.e. to reduce the sound energy passing through a building construction, the influence of an angle of sound wave incidence onto the partition (construction), etc. Sound pressure on the area of the partition may be uniform, whereas the amplitude of oscillations gets changed throughout the whole area of the partition. The article explores in what cases sound will pass most strongly through the partition of finite dimensions when space-frequency resonance occurs.Investigation showed that the sound energy absorption depended on deformation losses in that material. Changes in the angle of the sound wave incidence at the same frequencies create the opportunity for manifestation of alternation of maximums and minimums in the motion of plate amplitudes. The property of sound wave incidence, at the sound transmission through the plate of finite dimensions, confirms the rightfulness of the division of the curve of the frequency dependence of sound insulation into three ranges of frequencies with the different intensity of sound transmission.