Electric road vehicles emit a very low level of noise when being driven because the noise emission of the electric motor is negligible compared with that of an Internal Combustion (I.C.) engine. On the other hand, electric road vehicles emit noise when they are stationary and the battery is on charge. If an electric road vehicle is equipped with an on-board charger, this can be a source of noise during charging, together with a number of other components which may also be operating and producing noise. Such airborne noise should be minimised, to avoid public nuisance, and its intensity should be no higher than that permitted under existing limits or recommendations. This is the reason why it is important to measure the noise emission of the whole vehicle under precisely defined conditions. The airborne acoustical noise emission is expressed in terms of the sound power level of the electric road vehicle.