What's going on next door?
Total sound insulation is the ability of a total construction (partitions, ceiling, floor and all connections) to prevent sound from travelling through the ceiling void and through building elements. Sound insulation of ceilings is measured using the Ceiling Attenuation Class value (CAC); sound insulation of walls is measured using the Sound Transmission Class value (STC). The higher the CAC/STC value (in dB), the better the performance.
Mass, airtightness and sound absorption are the main properties that determine the sound insulation capacity of any material.