Single index for evaluating the sound absorption DLα

Definition and scope

Determination of the absorption performance of road noise barriers according to DIN EN 1793-1.

This assessment "does not determine in situ (extrinsic performance) which also depends on factors not related to the product itself, for example, screen size, and quality of installation work or , factors related to the site as the impedance of the ground, the geometry of the site, etc.. "(Extract from DIN EN 1793-1: 1997).

Evaluation method according to DIN EN ISO 354 

Expression of results: Calculation of the single index for evaluating the sound absorption DLα air according to DIN EN 1793-1 and 3

For each third octave band, weighting of the index index αs in accordance with normalized traffic spectrum (L) defined in standard NF EN 1793-3

The single index for evaluating the sound absorption DLα is classified as follows:

Catégory

DLα in dB

A0

undetermined

A1

<4

A2

4 à 7

A3

8 à 11

A4

>11

Example DLα test results