ABSTRACT
This chapter will try to review the state of the art in environmental noise measurements and monitoring, and nally provide a wide perspective on the role of measurements in Noise Directive 2002/49/EC.1 This also includes the estimation of the indicators Lden and Lnight, as dened by this directive. It is well known that to develop noise maps from noise measurements is not a good idea. There are many inconveniences in making maps in that way. (See Figure 3.1.)
Basically, what we try to capture during the measuring interval is not the total amount of noise detected at the microphone. What we really want to know is the specic sound,2 in other words, the noise generated by the target noise sources. The rest is the residual noise. Probably one of the most important problems that concern technicians is how to manage to avoid this residual noise, and sometimes it is quite complicated, even impossible.
