A comparator receives a threshold value and compares {HEAD ~ each} of the intermediate amplitude values to {TAIL ~ the threshold value} 
to
A comparator receives a threshold value and compares { HEAD ~ each } of the intermediate amplitude values to { TAIL ~ the threshold value }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL