:: Also, a note about power ratings-there is " power rating " and there is " actual power consumption . " These two numbers are not necessarily at all correlated, thanks to the magic of marketing B . S .-and electrical power may have absolutely no meaningful bearing on acoustic power out.
22.
The combination of location within the ocean and the sensitivity of arrays allowed the system to detect acoustic power of less than a watt at ranges of several hundred kilometres ( The system is so sensitive that it can even detect the presence of Soviet / Russian Tu-95 Bear 4-engine bombers flying overhead; the tips of the bombers'long propellers exceed the speed of sound, creating sonic booms as they rotate.
23.
However, the "'amplitude "'[ the amount of air displacement, or the distance a freely suspended surface ( a la a microphone diapham or an eardrum ) will move ] is proportional to the square root of the acoustic power, just as the voltage in an electric device is proportional to the square root of the power . "'Two sound sources being indentical in all respects except being out of phase cannot just cancel, as this would mean energy destroyed " '.
