{TAIL ~ A hearing aid apparatus} employs a single side band modulator which serves to convert an audio band of {HEAD ~ frequencies} into an upper and lower side band signal 
{ TAIL ~ A hearing aid apparatus } employs a single side band modulator which serves to convert an audio band of { HEAD ~ frequencies } into an upper and lower side band signal
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH