first summing amplifier means for generating a left right summing output signal which is a function of {HEAD ~ the sum} of said {TAIL ~ left and right output pulses} 
first summing amplifier means for generating a left right summing output signal which is a function of { HEAD ~ the sum } of said { TAIL ~ left and right output pulses }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL