Calibration of the system is provided by means for {HEAD ~ an operator} to specify {TAIL ~ tone densities} for the second medium that correlate to signal levels derived from the first medium for each channel 
to specify
Calibration of the system is provided by means for { HEAD ~ an operator } to specify { TAIL ~ tone densities } for the second medium that correlate to signal levels derived from the first medium for each channel
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH