a plurality of {HEAD ~ level control units} receiving said modified signals and providing {TAIL ~ normalized modified signals} having a constant amplitude 
a plurality of { HEAD ~ level control units } receiving said modified signals and providing { TAIL ~ normalized modified signals } having a constant amplitude
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH