ISO 5128:2023

This document specifies an engineering method 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 (e.g. 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.