The setting is there, it is called Sens followed by the usual XXXX format. Right now I am busy with another game...

but if you se this to zero, for which, the Hydrophones or the active sonar, or both?
ther is a unique value for Sens for each Active sonar of seven, and the pasive hydrophones of seven types.
Making it zero would make then un able to detect you?
I thought you wish them to be as above post?
Anyway, open AI_Sensors.dat, look for say "Type144P" following past that is "Sensitivity" after that a "ways beyond XX_XX_XX" is the real setting, it is not following immediately as normal (thus that tool will not work). that is where it lies.
I never really did anything with it (expect copy down the numbers), I know someone did and it does change the detection rate, better or worst.