Safety is neither the acoustic output of a street nor a stable feeling carried into it by an isolated pedestrian. Pereira and colleagues use interactive virtual-reality simulations of shared spaces, where vehicles and people coexist, to investigate how different soundscapes affect perceived safety under pedestrian and leisure scenarios. Natural, human and mechanical sound elements are integrated into spatially recognisable situations. This design makes participant activity part of the interpretation: the auditory signals relevant to someone crossing an ambiguous traffic space need not be evaluated like those relevant to someone dwelling there. The distinctive operation lies in manipulating a multisensory environment while retaining the perspective and task of its prospective user. Urban transport design, virtual-reality experimentation and psychoacoustics are thereby made commensurable for a bounded question. The experiment cannot claim to reproduce the risks or embodied vigilance of a live street; simulated exposure and stated safety remain different evidential registers from actual avoidance, collision probability or habitual use. That gap is productive for comparative design: it identifies conditions to test subsequently through ordinary walking rather than presenting laboratory-like immersion as a substitute for it.
