Typically, {HEAD ~ some subband data} is replaced with {TAIL ~ zeros} so that an error causes some of the frequency components to be lost 
is replaced with
Typically , { HEAD ~ some subband data } is replaced with { TAIL ~ zeros } so that an error causes some of the frequency components to be lost
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH