An acoustic emission leak simulator (10) for a nondestructive simulation of a leak in a structure employs a fluid supply with variable orifice (18) for controllably releasing the fluid to create a simulated leak source (20). An acoustic waveguide (22) acoustically coupled to the variable orifice (18) couples the sound waves into the structure (12) for simulation of a leak signal. Transducer (30) positioned at a predetermined distance from the simulated leak source (20) characterize the leak signals for a leak detection system.