The weighted characteristic A approximates the sound insulation of the cabin.

Professional Definition

Weighted characteristic A of the approximate sound insulation of the cabin (D'A) – the difference between the A-weighted sound level measured respectively in the room and in the cabin, while the background noise is used as a noise source.

This parameter is crucial in in situ studies (in the installation place). Unlike laboratory tests, where generated pink or white noise is used, here the source of excitation is actual background noise (e.g., machinery operation). The use of a A-weighting filter ensures that the measurement reflects how noise reduction is perceived by the human ear, placing less emphasis on very low frequencies to which we are less sensitive.

Acoustics in Simple Words

Imagine standing in the rain (background noise) and stepping under a tent (cabin). To check how good this tent is, you do not pour water on it with a garden hose (artificial sound source), but check how much drier you are using the rain that is already falling. A-weighted insulation is a measure that tells us: "it is this much quieter inside than outside," with the measurement adjusted to what is most bothersome to your ears, not the measuring equipment.

Summary

This is a practical indicator determining the actual acoustic effectiveness of the cabin at its installation site, utilizing the existing background noise. The result is given in decibels (dB) considering the A-weighting curve, allowing for an assessment of real working comfort inside the enclosure.