{HEAD ~ A hands free telephone set} has {TAIL ~ both transmit and receive channels} open for the reception of signals, while still inhibiting feedback singing 
{ HEAD ~ A hands free telephone set } has { TAIL ~ both transmit and receive channels } open for the reception of signals , while still inhibiting feedback singing
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH