During censuses of wolves, performed with the wolf howling technique, in the Foreste Casentinesi National Park, we recorded answers of wolf packs and isolated individuals. Most difficulties were caused by the distance between wolves and the recording equipment. The aim of this preliminary analysis was to verify if it was possible, in the wild, to distinguish by means of sonagraphic analysis: at adults from pups; b) the number of individuals of each pack; c) different adult individuals from each other. The first distinction is possible thanks to the different frequency range of adult and pup vocalisations. The substantial overlapping of different vocalisations makes the second aim difficult, but it is possible to determine a minimum number of individuals. The third aim is difficult to achieve because only few vocalisations of each individual can be collected.