Agree to Sarah...
Interestingly the term went already into all the major german-english online dictionaries (dict.cc, odge.de). So, who is copying whom?
Furthermore the misleading meaning (supersonic sounding - "Beschallung") is indeed (in relation with PA-systems) only used in german sites as ondondon irl already dicovered and I can confirm.
To sum up: at least replace the [engin.] and add a [coll.] and maybe something like "Geiler Sound", "Wahnsinns-sound" at the german side.
The term seems apperantly not to be show up in English in the meaning of official (=engineering) usage for electro-acoustical sound systems.
It's your choice and needs a further discussion to add the new technical terms like "Echolot" or "Ultraschall-Untersuchung", maybe also "Sonar" (see the Wikipedia-links below).
I just found that the english Wikipedia calls the "Echolot" "Echo sounding". Sorry, I have no time to do further research now.
(By the way RADAR is working with electromagnetic, Echolot of course with ulrrasonic sound waves)http://de.wikipedia.org/wiki/Echolothttp://en.wikipedia.org/wiki/Echo_soundinghttp://en.wikipedia.org/wiki/Sonarhttp://de.wikipedia.org/wiki/Sonar