Weighted sound insulation index of the cabin

Professional Definition

The acoustic insulation of the cabin in the normative frequency range reduced to a single numerical value according to the method specified in the standard PN-EN ISO 717-1.

This indicator is the result of a mathematical weighting procedure that overlays the measured sound insulation characteristic of the cabin onto a reference curve. The purpose of this procedure is to account for the physiology of human hearing – our ears are not equally sensitive to all sounds. By reducing multiple measurement values (for 1/3 octave or octave bands) to a single number, it is possible to quickly compare the acoustic properties of different cabins with respect to the standard PN-EN ISO 717-1.

Acoustics in Simple Terms

Imagine that the acoustic insulation of a cabin is a shield protecting against gunfire (sound). In reality, this shield is thicker in one place (better at damping higher frequencies) and thinner in another (less effective at damping lower frequencies). Instead of describing the thickness of the shield in every millimeter, we provide a single number that indicates its overall strength class. The weighted index is precisely such a "final grade" on the cabin's certificate. The higher this value, the less noise penetrates inside (or escapes outside), and we perceive this as "better silence."

Summary

The weighted acoustic insulation index of the cabin is a standard, single numerical parameter that defines the sound insulation effectiveness of the complete cabin structure. It allows for objective comparison of products from different manufacturers without the need for deep spectral analysis.