Sound insulation

Professional Definition

Sound insulation is the resistance of a partition to the transmission of airborne or impact sounds.

This parameter determines how effectively a wall, ceiling, or window blocks the flow of acoustic energy from one room to another. We distinguish between insulation from airborne sounds (e.g., speech, music), expressed by the indicator $R_w$, and insulation from impact sounds (e.g., footsteps, moving furniture), expressed by the level $L_{n,w}$. Physically, insulation mainly depends on the mass of the partition and its tightness, according to the so-called mass law.

Acoustics in Simple Words

To understand the role of insulation, imagine an aquarium. To prevent water from leaking outside, you need thick, airtight glass – this is insulation (blocking). It should not be confused with a sponge thrown inside, which absorbs water (that would be acoustic adaptation/absorption). Sound insulation acts like a solid shield – the heavier and tighter it is, the less “shot” (sound) will pass to the other side.

Summary

Sound insulation is the ability of a building partition to keep noise from external or neighboring rooms at bay. It is crucial to distinguish between protection against airborne noise (conversations) and impact noise (footsteps), as they require different technical solutions.