Advances in technology (Bluetooth headsets, ‘iPods’, quieter cars, helmets) are leading to situations where an individual's perception of the surrounding environment is hindered, making him/her more vulnerable to accidents and/or intentional dangers. Examples include: a driver unaware of a fast moving emergency vehicle; a motorbike or cyclist wearing a protection helmet; a civil protection foraging robot or vehicle on patrol. This PhD research project aims to study and develop detection and warning systems for users or equipment, allowing constant sound monitoring of the environment and identification of potential threats. The project straddles across a set of multi-disciplinary skills such as sensor engineering (with particular emphasis on acoustic detection), digital signal processing and cognitive behaviour. The research and development of advanced acoustic sensor networks and associated signal acquisition and analysis would form the core of the doctorate. Collaboration with psychology and social sciences partners will be provided to support the areas of cognition and human behaviour.