a first filter bank receiving an input signal and providing frequency estimates for {HEAD ~ an initial indication} of {TAIL ~ a presence} of each of said targeted frequencies 
a first filter bank receiving an input signal and providing frequency estimates for { HEAD ~ an initial indication } of { TAIL ~ a presence } of each of said targeted frequencies
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH