The method 2 further comprising updating {HEAD ~ trackers} before determining a respective said fundamental frequency of the respective time frame, wherein said updating of {TAIL ~ the trackers} includes at least one of: 
The method 2 further comprising updating { HEAD ~ trackers } before determining a respective said fundamental frequency of the respective time frame , wherein said updating of { TAIL ~ the trackers } includes at least one of :
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH