Sound Insulation Theory
Sound is the propagation of mechanical energy through vibrations in the air. When these vibrations hit upon a surface, they are either transmitted, reflected or absorbed (& dissipated in form of heat).

Noise Insulation by Reflection:
Monolithic glass and insulated glass units (without gas) work mainly on the principle of sound reflection.  In this case sound energy is not converted into a different energy form, but its direction of propagation is changed.

Noise Insulation by Absorption:
In this case the material absorbs the sound energy and dissipates in form of heat.

Dual Action of AIS Acousticglas™
The first pane of AIS AcousticglasTM performs the role of mainly reflecting the sound waves. Sound energy that gets transmitted through the first pane, is then further absorbed by the interlayers and dissipated in in form of heat. This dual action, results in significantly better acoustic insulation compared to both monolithic glass as well as most insulated glass units.