The Privacy Risk Area Assessment Tool (PRAAT) for audio monitoring has been developed in the frame of EAR-IT, a European research project exploring the potential of audio monitoring for smart buildings and smart cities. The project addresses several privacy related issues in different countries and contexts, including outdoor and indoor audio monitoring. By involving real end-users in different legal environments, the project has to be very careful in respecting the privacy rights and has to make sure that its experiments are compliant with the a complex web of International, European and national obligations. Based on a detailed legal analysis, the authors have elaborated a Privacy Risk Area Assessment Tool (PRAAT) for audio monitoring. It has been designed to be user-friendly for users with limited legal background, such as researchers, public administrations and other interested stake holders in evaluating the level of legal risk bound to any project of audio monitoring deployment.