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