Ground microphones work on the principle of sound amplification. When water leaks from a pipe underground, it creates noise due to the pressure difference and the turbulence of the water flow. This noise, though often faint, can be detected by sensitive microphones.

The ground microphone is placed directly on the ground or on the surface of the pipe. It picks up the sounds generated by the leak, which are often at frequencies that are not easily heard by the human ear.

The operator listens to the sounds picked up by the microphone through headphones or a speaker attached to the device. By moving the microphone around the area suspected of having a leak, the operator can pinpoint the location of the leak based on the intensity and quality of the sound detected.

Ground microphones often have filters and amplification controls to help isolate and enhance the sounds of the leak while minimizing background noise. This makes it easier for the operator to distinguish the leak sounds from other environmental noises.

Once a potential leak location is identified using the ground microphone, it’s often confirmed using other methods such as correlators or leak noise correlators. These devices analyze the sound picked up by multiple microphones placed at different points along the pipe to triangulate the exact location of the leak.