Abstract
Moto- cross is widely spread in the Netherlands. While it is a noisy activity, a study is made to quantify the current noise emission. Another important aim of the study was to indicate an emission measurement method by which the noise production of individual motorcycles can be checked in a way that is representative for the noise production while racing. Measurements have been performed during varies moto- cross races - at distance and along the track - and on individual motorcycles in several categories.