DIN ISO 5128:2026-11

This document specifies an engineering method of accuracy class 2 for measuring the interior sound of road vehicles of categories M and N under typical driving conditions. It does not apply to agricultural tractors and field machinery. It specifies the conditions for obtaining reproducible and comparable measurements of sound pressure levels inside a vehicle. These measurements are used to obtain a representative average sound level during a typical driving cycle to enable assessment of adverse effects on human health. The results can be used for - standardized assessment of interior sound for comparisons (for example, benchmark, consumer information programs), - verification tests, to decide whether or not the sound inside the vehicle is in accordance with specifications, - regulatory purposes, for example for evaluation of sound in relation to labour or for general health standards, and - monitoring tests, in order to check that the sound inside the vehicles has not changed since delivery, or between individual units of a consignment of vehicles. This document does evaluate the exposure to interior sound of vehicles in a way as it is commonly used for scientific effects on human health. It does not assess maximum interior sound of a vehicle under extreme driving situations, as today's measured maximum sound pressure levels inside vehicles are far away from the risk to create instantaneous hearing damages. The responsible national standardization committee is Working Committee NA 001-01-05 AA "Geräuschemissionsmessungen an Fahrzeugen einschließlich Messungen im Fahrgastraum und am Arbeitsplatz" ("Measurement of sound exposition on road vehicles, including measurements inside the passenger compartment and at the workplace") at DIN/VDI Standards Committee Acoustics, Noise Control and Vibration Engineering (NALS).