This question is difficult to answer on a general basis, as many other questions published here.
Details are needed as acoustics tests instrumentation/devices are available from different producers,in different forms and for different fluids. Accuracy will differ, and be greatly dependent also on fluid conditions and flow downstream/upstream and local disturbances.
Secondly comes the requirement for allowable leakage, which consequences a leakages of a given size will have, and the time and means of reporting and reaction if there is a failure.
The company's QA procedures, existing and new, would also be an issue. It seems obvious for me that it would be difficult to reach the same accuracy as a full, standard visual or 'normal' directly observed leakage test on a general basis.
Others might have practical experience if you details your question.
