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