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