Inaudible smart crowds security through existing loudspeakers”
Zoovel Ultrasound Connectivity (Zoovel-UC) project is a D2D  connectivity to raise the safety and security in crowded areas such as sports stadiums, concert halls, open space events, subway, etc. providing real-time crowd management. Zoovel-UC technology performs direct and selective communication to the spectators and utilizes geospatial intelligence to shift the flow of fans and minimize crowds in real-time, improving the efficiency of current security protocols. 
Since the attack on the Twin Towers in 2001, terrorism has been on our collective unconscious as the main threat to security. The recently attacks happened in Paris and Brussels again reminded the vulnerability of the international security system and the difficulty to deal effectively with this type of unconventional threat. Crowd events provide a potential target for terrorist activity, besides they are susceptible to other various threats, such as natural disasters, crowding and fan violence. With the uncertainty of terrorist actions and fan behaviour, it is impossible to ensure a risk-free environment at crowd venues. It is therefore a matter of how event organizers prepare, respond, and recover to mitigate the consequences of emergencies. Good countermeasures and contingency planning can protect crowd areas from disruption and ultimately enhance spectator confidence.