Understanding Acoustic Emission Testing- Reading 1 Part B-A

Area surveys using acoustic loggers
In the last few years other acoustic techniques have been developed to
optimise water leakage management in identifying leakage areas prior to
directing leak detection operators to pinpoint the leak.
Thus have been developed systems for acoustic noise monitoring and
recording that can be permanently or time limited installed at hydrants, valves
or house connections. These "noise loggers" record typical noises in the
network during low consumption hours at night and identify areas of potential
leakage for further investigation. The ultimate advance consists in
transmission of leak presence from the noise loggers to a receiver module,
which may be hand carried or vehicle-mounted.
Charlie Chong/ Fion Zhang
http://www.ndt.net/article/wcndt00/papers/idn183/idn183.htm