Roads and traffic are the most important source of noise in the environment. Moreover, much research effort has been aimed to identify and to quantify road impacts on animal populations. Species composition, richness and abundance are modified by road presence. Thus, roads not only alter natural soundscapes by traffic noise but also by changes in the animal communities which are involved in the creation of that soundscape. Furthermore, other indirect impacts caused by roads as greater accessibility or land-use changes may become main factors of natural soundscape modification. For all these reasons, the spatial configuration of the soundscapes in a region is related to the road network. Roads, especially main highways, are not distributed at random but tend to follow certain landscape units. Road network is also known to have fractal features and its patterns are closely related to the urban system. This research explores the influence of these factors in the spatial alteration of natural soundscapes caused by traffic noise. Calm areas with low road densities have been proposed as target areas for conservation. The initial purpose was the preservation of relatively unaltered communities far away from road impacts but these zones could be also used to protect natural soundscapes. These calm zones partially overlap with protected areas but there are also important calm areas that remain unprotected. The approach here showed could serve as theoretical framework to study the spatial interactions between road networks and soundscapes and, therefore, be used to locate these calm areas.