{HEAD ~ Each} of these spectral regions is defined by {TAIL ~ a respective center frequency} within a common frequency range 
is defined by
{ HEAD ~ Each } of these spectral regions is defined by { TAIL ~ a respective center frequency } within a common frequency range
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH