{HEAD ~ A tone detector} for detecting {TAIL ~ a tone} having a plurality of targeted frequencies, comprising: 
for detecting
{ HEAD ~ A tone detector } for detecting { TAIL ~ a tone } having a plurality of targeted frequencies , comprising :
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH