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