How an Acoustic Water Leak Detector Finds Hidden Leaks An acoustic water leak detector listens for vibrations made by water escaping a pressurized pipe. To locate a hidden leak, a technician listens at accessible points along the pipe, then checks the floor or ground nearby. Comparing the sounds helps narrow down where to inspect or repair, often without opening a large area first. The sound travels through pipe walls and soil, so depth, pipe material, and traffic noise can m