Amusing things found while reading at work:

Apparently the tried and tested method of finding a cable fault is to attach a thumper to one end, then employ the “fault-locator-ear-on-the-ground-butt-in-the-air” technique.

Traffic cones are suggested as an alternate tool for sound amplification.

From the Megger document “Fault Finding Solutions” -

For the un-initiated: a “thumper” is a device that sends repeated electrical surges down a cable. When a surge of energy hits the fault location, it makes a audible sound which you can pinpoint by listening for the ’thumps’ in the ground.

Needless to say, don’t do this while any electronics are connected to the cable.