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