The Directive 2002/49 on evaluation and management of the environmental noise demands in case of agglomerations, a series of information that one must communicate to the Commission, between which there is the number of people whose housings are exposed to every range of values of Lden and Lnight in dBA. In this work they present the criteria contemplated in the delimiting of the agglomerations inside Catalonia's territory, as well as the methodologies used in the estimation of the audible levels and the population exposed to the different indicators of noise with the results obtained.