A pool monitoring system includes a hydrophone configured to generate an electrical signal in response to receiving a pressure wave in the liquid of a pool, and a processor configured to receive the electrical signal and generate a trigger signal, when the electrical signal includes a characteristic signature over a time period within a predetermined range of time periods.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of and claims priority to U.S. application Ser. No. 10/697,143, filed on Oct. 30, 2003.
